阅读说明：本技术 电阻元件及功率放大电路 (Resistance element and power amplification circuit ) 是由 宫岛贤一 加藤由明 西尾明彦 本吉要 于 2020-03-24 设计创作，主要内容包括：电阻元件(100)具备基板(101)、第1氮化物半导体层(102)、第2氮化物半导体层(103)、设置在第1氮化物半导体层(102)与第2氮化物半导体层(103)的界面的第1氮化物半导体层(102)侧的二维电子气层(107)、与二维电子气层(107)欧姆连接的第1电极(113)、与二维电子气层(107)欧姆连接的第2电极(114)、以及在平面视图中设置在第1电极(113)与第2电极(114)之间的绝缘层；二维电子气层(107)作为电阻要素发挥功能；在平面视图中在第1电极(113)与第2电极(114)之间的绝缘层的上方不配置导电层；具有电阻值稳定化构造,该电阻值稳定化构造用于使电阻要素的电阻值一定。(The resistance element (100) is provided with a substrate (101), a 1 st nitride semiconductor layer (102), a 2 nd nitride semiconductor layer (103), a two-dimensional electron gas layer (107) arranged on the 1 st nitride semiconductor layer (102) side of the interface of the 1 st nitride semiconductor layer (102) and the 2 nd nitride semiconductor layer (103), a 1 st electrode (113) in ohmic connection with the two-dimensional electron gas layer (107), a 2 nd electrode (114) in ohmic connection with the two-dimensional electron gas layer (107), and an insulating layer arranged between the 1 st electrode (113) and the 2 nd electrode (114) in a plan view; the two-dimensional electron gas layer (107) functions as a resistance element; a conductive layer is not disposed over the insulating layer between the 1 st electrode (113) and the 2 nd electrode (114) in a plan view; the resistance value stabilizing structure is provided for making the resistance value of the resistance element constant.)

1. A resistance element, characterized in that,

the disclosed device is provided with:

a substrate;

a 1 st nitride semiconductor layer provided above the substrate;

a 2 nd nitride semiconductor layer provided above the 1 st nitride semiconductor layer and having a band gap larger than that of the 1 st nitride semiconductor layer;

a two-dimensional electron gas layer provided on the 1 st nitride semiconductor layer side of the interface between the 1 st nitride semiconductor layer and the 2 nd nitride semiconductor layer;

a 1 st electrode provided above the 1 st nitride semiconductor layer and ohmically connected to the two-dimensional electron gas layer;

a 2 nd electrode disposed above the 1 st nitride semiconductor layer and spaced apart from the 1 st electrode in a plan view, and ohmically connected to the two-dimensional electron gas layer; and

an insulating layer which is in contact with an upper surface of the 2 nd nitride semiconductor layer and is provided between the 1 st electrode and the 2 nd electrode in a plan view;

the two-dimensional electron gas layer provided between the 1 st electrode and the 2 nd electrode in a plan view functions as a resistance element;

a conductive layer is not provided above the insulating layer between the 1 st electrode and the 2 nd electrode in a plan view;

the resistance value stabilizing structure is provided for making the resistance value of the resistance element constant.

2. A resistive element comprising a resistive element portion and a conductive control layer,

the resistance element portion includes:

a substrate;

a 1 st nitride semiconductor layer provided above the substrate;

a 2 nd nitride semiconductor layer provided above the 1 st nitride semiconductor layer and having a band gap larger than that of the 1 st nitride semiconductor layer;

a two-dimensional electron gas layer provided on the 1 st nitride semiconductor layer side of the interface between the 1 st nitride semiconductor layer and the 2 nd nitride semiconductor layer;

a 1 st electrode provided above the 1 st nitride semiconductor layer and ohmically connected to the two-dimensional electron gas layer;

a 2 nd electrode disposed above the 1 st nitride semiconductor layer and spaced apart from the 1 st electrode in a plan view, and ohmically connected to the two-dimensional electron gas layer; and

an insulating layer which is in contact with an upper surface of the 2 nd nitride semiconductor layer and is provided between the 1 st electrode and the 2 nd electrode in a plan view;

the two-dimensional electron gas layer provided between the 1 st electrode and the 2 nd electrode in a plan view functions as a resistance element;

the above-mentioned conductive control layer is,

an insulating layer disposed between the 1 st electrode and the 2 nd electrode in a plan view;

a length of the conductive control layer in a direction in which the 1 st electrode and the 2 nd electrode are arranged in a plan view is 1/2 or more of an interval between the 1 st electrode and the 2 nd electrode;

applying an electric field to the two-dimensional electron gas layer in response to a voltage supplied from the outside of the resistance element portion to control a resistance value of the resistance element;

the resistance element has a resistance value stabilizing structure for making the resistance value of the resistance element constant.

3. The resistive element of claim 1 or 2,

the resistance value stabilization structure is configured as follows:

the insulating layer is made of silicon nitride (SiN),

the composition ratio Si/N of the insulating layer at the interface between the insulating layer and the 2 nd nitride semiconductor layer is 1.1 to 2.3.

4. The resistive element according to any one of claims 1 to 3,

the resistance value stabilization structure described above is a structure having the 1 st hole injection electrode,

the 1 st hole injection electrode is provided in contact with the upper surface of the 2 nd nitride semiconductor layer on the 1 st electrode side between the 1 st electrode and the 2 nd electrode, is electrically connected to the 1 st electrode, and injects holes into the 2 nd nitride semiconductor layer when the 1 st electrode is at a high potential with respect to the 2 nd electrode.

5. The resistive element of claim 4,

the resistance value stabilization structure also has a 2 nd hole injection electrode,

the 2 nd hole injection electrode is provided in contact with the upper surface of the 2 nd nitride semiconductor layer on the 2 nd electrode side between the 1 st electrode and the 2 nd electrode, is electrically connected to the 2 nd electrode, and injects holes into the 2 nd nitride semiconductor layer when the 2 nd electrode is at a high potential with respect to the 1 st electrode.

6. The resistive element according to any one of claims 1 to 3,

the resistance value stabilization structure is a structure having a 1 st electron extraction electrode,

the 1 st electron extraction electrode is provided in contact with an upper surface of the 2 nd nitride semiconductor layer on the 1 st electrode side between the 1 st electrode and the 2 nd electrode in a plan view, is electrically connected to the 1 st electrode, and extracts electrons from the 2 nd nitride semiconductor layer when the 1 st electrode has a high potential with respect to the 2 nd electrode.

7. The resistive element of claim 6,

the resistance value stabilization structure also has a 2 nd electron extraction electrode,

the 2 nd electron extracting electrode is provided in contact with an upper surface of the 2 nd nitride semiconductor layer on the 2 nd electrode side between the 1 st electrode and the 2 nd electrode in a plan view, is electrically connected to the 2 nd electrode, and extracts electrons from the 2 nd nitride semiconductor layer when the 2 nd electrode has a high potential with respect to the 1 st electrode.

8. The resistive element according to any one of claims 1 to 7,

the resistance value stabilization structure has a stress buffer layer provided above the insulating layer.

9. The resistive element according to any one of claims 1 to 8,

the resistance value stabilization structure described above is a structure having an element separation layer,

the element separation layer is provided so as to surround the 1 st nitride semiconductor layer in a plan view, and contains inactive ions;

a distance between an upper surface of the element separation layer and an upper surface of the substrate is smaller than a distance between a lower surface of the two-dimensional electron gas layer and the upper surface of the substrate.

10. The resistive element according to any one of claims 1 to 9,

the resistance value stabilizing structure described above is a structure having a high resistance layer,

the high-resistance layer is provided between the substrate and the 1 st nitride semiconductor layer, and has a higher resistivity than the substrate.

11. The resistive element according to any one of claims 1 to 10,

the resistance value stabilization structure includes a low-temperature characteristic resistance element portion which is provided above the substrate and has a temperature coefficient smaller than that of the two-dimensional electron gas layer;

the low-temperature characteristic resistance element portion includes a 3 rd electrode and a 4 th electrode provided at a position spaced apart from the 3 rd electrode in a plan view;

the 1 st electrode is connected to the 3 rd electrode;

the 2 nd electrode is connected to the 4 th electrode.

12. The resistive element according to any one of claims 1 to 3,

the resistance value stabilization structure is configured as follows:

the 1 st electrode and the 2 nd electrode are embedded in a part of the 1 st nitride semiconductor layer from the upper surface of the 2 nd nitride semiconductor layer so as to be in contact with the two-dimensional electron gas layer, respectively.

13. The resistive element according to any one of claims 1 to 12,

the resistance value stabilization structure is configured as follows:

the insulating layer is provided at a distance from each of the 1 st electrode and the 2 nd electrode in a plan view.

14. A power amplifying circuit, characterized in that,

comprising:

a resistive element according to any one of claims 1 to 13;

a field effect transistor disposed above the substrate; and

a capacitor;

the field effect transistor has a source electrode, a drain electrode, and a gate electrode;

one of the 1 st electrode and the 2 nd electrode is electrically connected to the gate electrode;

the other of the 1 st electrode and the 2 nd electrode is electrically connected to the drain electrode via the capacitor.

15. A power amplifying circuit, characterized in that,

comprising:

a field effect transistor disposed above the substrate; and

a bias circuit for providing a gate voltage of the field effect transistor and setting a drain current of the field effect transistor;

the bias circuit includes the resistor element according to any one of claims 1 to 13.

Technical Field

The present invention relates to a semiconductor device, and more particularly to a resistance element made of a nitride semiconductor and a power amplifier circuit using the resistance element.

Background

Group III nitride semiconductors, particularly GaN and AlGaN, have a high dielectric breakdown voltage due to the size of their band gap (gap). Further, a hetero (hetero) structure such as AlGaN/GaN can be easily formed. In this heterostructure, a channel (two-Dimensional Electron Gas, 2DEG (2Dimensional Electron Gas)) of electrons having a high mobility and a high concentration can be generated on the GaN layer side of the AlGaN/GaN interface, based on spontaneous polarization due to a difference in ion radius, fixed charges due to piezoelectric polarization caused by a difference in lattice constant between AlGaN and GaN, and a difference in band gap. By controlling the two-dimensional Electron gas channel, a High Electron Mobility Transistor (HEMT) can be formed. Group III nitride semiconductors are used in electronic devices such as Field Effect Transistors (FETs) and diodes for power applications due to their characteristics of high withstand voltage, high speed, and large current.

In recent years, not only discrete products in which an FET and a diode are used alone, but also integrated circuits including a resistor element and a capacitor have been increasingly used. Examples of the resistive element used here include a metal thin film resistor, an n-type or p-type group III nitride semiconductor grown by epitaxy, and a resistive element using a two-dimensional electron gas as described in patent document 1. In particular, when the resistance element is formed on the same chip as the HEMT, the resistance element using the two-dimensional electron gas can be formed at the same time as the HEMT, which is advantageous in terms of manufacturing cost.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 5707463

Disclosure of Invention

Problems to be solved by the invention

However, in a resistance element using a two-dimensional electron gas as a resistance element, the carrier concentration of the two-dimensional electron gas changes due to various reasons, and thus the resistance value may fluctuate during use. For example, in a circuit including the resistance element, a wiring layer (conductive layer) disposed particularly in the circuit strongly affects a resistance value by generating an electric field in the periphery. In this case, power consumption of the circuit increases or a desired characteristic is not obtained, and in the worst case, a trouble occurs in which the circuit does not operate. The reason why the resistance value varies is considered to be several factors, including depletion of carriers by electron traps at the semiconductor surface level, increase of carrier diffusion due to heat, and the like. In addition, since a high-concentration two-dimensional electron gas is generated at a hetero interface of GaN/AlGaN or the like by piezoelectric polarization of a group III nitride semiconductor, particularly GaN and AlGaN, the carrier concentration also fluctuates due to a change in external stress. This variation in carrier concentration causes variation in resistance value. In the case of element isolation by ion implantation, ions injected into the element isolation region by self-heating during operation move, carriers diffuse, and the resistance value varies.

Accordingly, an object of the present invention is to provide a resistance element or the like exhibiting a stable resistance value with little variation.

Means for solving the problems

A resistance element according to an aspect of the present invention includes: a substrate; a 1 st nitride semiconductor layer provided above the substrate; a 2 nd nitride semiconductor layer provided above the 1 st nitride semiconductor layer and having a band gap larger than that of the 1 st nitride semiconductor layer; a two-dimensional electron gas layer provided on the 1 st nitride semiconductor layer side of the interface between the 1 st nitride semiconductor layer and the 2 nd nitride semiconductor layer; a 1 st electrode provided above the 1 st nitride semiconductor layer and ohmically connected to the two-dimensional electron gas layer; a 2 nd electrode disposed above the 1 st nitride semiconductor layer and spaced apart from the 1 st electrode in a plan view, and ohmically connected to the two-dimensional electron gas layer; and an insulating layer which is in contact with an upper surface of the 2 nd nitride semiconductor layer and is provided between the 1 st electrode and the 2 nd electrode in a plan view; the two-dimensional electron gas layer provided between the 1 st electrode and the 2 nd electrode in a plan view functions as a resistance element; a conductive layer is not provided above the insulating layer between the 1 st electrode and the 2 nd electrode in a plan view; the resistance value stabilizing structure is provided for making the resistance value of the resistance element constant.

In addition, a resistance element according to an aspect of the present invention is a resistance element including a resistance element portion and a conductive control layer, the resistance element portion including: a substrate; a 1 st nitride semiconductor layer provided above the substrate; a 2 nd nitride semiconductor layer provided above the 1 st nitride semiconductor layer and having a band gap larger than that of the 1 st nitride semiconductor layer; a two-dimensional electron gas layer provided on the 1 st nitride semiconductor layer side of the interface between the 1 st nitride semiconductor layer and the 2 nd nitride semiconductor layer; a 1 st electrode provided above the 1 st nitride semiconductor layer and ohmically connected to the two-dimensional electron gas layer; a 2 nd electrode disposed above the 1 st nitride semiconductor layer and spaced apart from the 1 st electrode in a plan view, and ohmically connected to the two-dimensional electron gas layer; and an insulating layer which is in contact with an upper surface of the 2 nd nitride semiconductor layer and is provided between the 1 st electrode and the 2 nd electrode in a plan view; the two-dimensional electron gas layer provided between the 1 st electrode and the 2 nd electrode in a plan view functions as a resistance element; the conductive control layer is disposed above the insulating layer between the 1 st electrode and the 2 nd electrode in a plan view; a length of the conductive control layer in a direction in which the 1 st electrode and the 2 nd electrode are arranged in a plan view is 1/2 or more of an interval between the 1 st electrode and the 2 nd electrode; applying an electric field to the two-dimensional electron gas layer in response to a voltage supplied from the outside of the resistance element portion to control a resistance value of the resistance element; the resistance element has a resistance value stabilizing structure for making the resistance value of the resistance element constant.

In addition, a power amplifier circuit according to an aspect of the present invention includes: the above-described resistance element; a field effect transistor disposed above the substrate; and a capacitor; the field effect transistor has a source electrode, a drain electrode, and a gate electrode; one of the 1 st electrode and the 2 nd electrode is electrically connected to the gate electrode; the other of the 1 st electrode and the 2 nd electrode is electrically connected to the drain electrode via the capacitor.

In addition, a power amplifier circuit according to an aspect of the present invention includes: a field effect transistor disposed above the substrate; and a bias circuit for providing a gate voltage of the field effect transistor and setting a drain current of the field effect transistor; the bias circuit includes the above-described resistance element.

Effects of the invention

According to the present invention, a resistance element or the like exhibiting a stable resistance value with little variation can be provided.

Drawings

Fig. 1 is a plan view and a sectional view of a resistance element according to embodiment 1.

Fig. 2A is a cross-sectional view of the resistive element according to embodiment 1 before and after voltage application.

Fig. 2B is a conceptual diagram showing current-voltage characteristics before and after voltage application of the resistive element according to embodiment 1.

Fig. 3 is a cross-sectional view of the resistance element according to modification 1 of embodiment 1 and a diagram showing a resistance value change rate.

Fig. 4A is a plan view and a cross-sectional view of a field effect transistor formed on the same substrate as the resistance element of modification 1 of embodiment 1.

Fig. 4B is a graph showing the relationship between the resistivity and the composition ratio Si/N of the insulating layer 1 in modification 1 of embodiment 1.

Fig. 5 is a cross-sectional view of the resistance element according to modification 2 of embodiment 1 and the resistance element according to modification 3 of embodiment 1.

Fig. 6 is a cross-sectional view of the resistance element according to modification 4 of embodiment 1 and the resistance element according to modification 5 of embodiment 1.

Fig. 7A is a cross-sectional view of a resistance element according to modification 6 of embodiment 1.

Fig. 7B is a conceptual diagram illustrating current-voltage characteristics before and after stress is applied from the outside to the resistive element according to modification 6 of embodiment 1.

Fig. 8A is a diagram illustrating movement of the inactive ions of the resistance element according to embodiment 1.

Fig. 8B is a conceptual diagram showing current-voltage characteristics before and after the migration of the inactive ions of the resistance element according to embodiment 1.

Fig. 9 is a plan view and a cross-sectional view of a resistance element according to modification 7 of embodiment 1.

Fig. 10A is a diagram illustrating the resistance of the resistive element according to embodiment 1.

Fig. 10B is a conceptual diagram showing current-voltage characteristics at normal temperature and at high temperature of the resistive element according to embodiment 1.

Fig. 11 is a cross-sectional view of a resistance element according to modification 8 of embodiment 1.

Fig. 12 is a plan view and a cross-sectional view of a resistance element according to modification 9 of embodiment 1.

Fig. 13 is a plan view and a cross-sectional view of a resistance element according to modification 10 of embodiment 1.

Fig. 14 is a plan view and a cross-sectional view of a resistance element according to modification 11 of embodiment 1.

Fig. 15A is a circuit diagram showing a power amplifier circuit according to embodiment 2.

Fig. 15B is a diagram showing the temperature dependence of the gain of the field effect transistor included in the power amplifier circuit of embodiment 2.

Fig. 16A is a circuit diagram showing a power amplifier circuit according to embodiment 3.

Fig. 16B is a diagram showing the temperature dependence of the gate voltage of the field effect transistor and the temperature dependence of the drain current of the field effect transistor included in the power amplifier circuit of embodiment 3.

Fig. 17 is a plan view and a sectional view of a resistance element according to embodiment 4.

Fig. 18 is a diagram showing a state of generation of a two-dimensional electron gas layer in a case where a potential is applied to the 1 st conductive control layer of the resistive element according to embodiment 4.

Fig. 19 is a plan view and a cross-sectional view of a resistance element according to modification 1 of embodiment 4.

Fig. 20 is a plan view and a cross-sectional view of a resistance element and a field effect transistor according to modification 1 of embodiment 4.

Fig. 21A is a circuit diagram showing a power amplifier circuit according to embodiment 5.

Fig. 21B is a diagram showing the temperature dependence of the gain of the field effect transistor included in the power amplifier circuit of embodiment 5.

Fig. 22A is a circuit diagram showing a power amplifier circuit according to embodiment 6.

Fig. 22B is a diagram showing a relationship between a control voltage and a drain current of a field effect transistor included in a power amplifier circuit according to embodiment 6.

Fig. 23A is a circuit diagram showing a power amplifier circuit according to embodiment 7.

Fig. 23B is a graph showing the temperature dependence of the gate voltage and the temperature dependence of the drain current of the field-effect transistor in embodiment 7.

Detailed Description

Hereinafter, the resistance element according to the embodiment will be specifically described with reference to the drawings. The embodiments described below are all examples of general or specific. The numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of the constituent elements, and the like shown in the following embodiments are examples and are not intended to limit the present invention.

In the following embodiments, the terms "upper" and "lower" do not refer to upper (vertically upper) and lower (vertically lower) in absolute space recognition. The terms "upper" and "lower" are applicable not only to a case where two components are disposed with a space therebetween and another component is present between the two components, but also to a case where two components are disposed in close contact with each other and the two components are in contact with each other.

In the present specification and the drawings, the x-axis, the y-axis, and the z-axis represent three axes of a three-dimensional orthogonal coordinate system. In each embodiment, the z-axis direction is assumed to be a vertical direction, and a direction perpendicular to the z-axis (a direction parallel to the xy plane) is assumed to be a horizontal direction. In the embodiments described below, the z-axis positive direction may be referred to as the upper side, the z-axis negative direction may be referred to as the lower side, and the surface on the z-axis positive direction side may be referred to as the upper surface and the surface on the z-axis negative direction side may be referred to as the lower surface.

In the present specification, the "plan view" refers to a view of the substrate side of the resistive element when the substrate is viewed from the z-axis direction, and the view in this case is referred to as a plan view. The cross-sectional view is a view showing only a plane indicated by the cross-section.

In this specification, the electrical connection is also referred to simply as connection.

In this specification, silicon is sometimes represented as Si, silicon carbide is sometimes represented as SiC, aluminum nitride is sometimes represented as AlN, gallium nitride is sometimes represented as GaN, indium nitride is sometimes represented as InN, indium gallium nitride is sometimes represented as InGaN, aluminum gallium nitride is sometimes represented as AlGaN, aluminum indium gallium nitride is sometimes represented as AlInGaN, hydrogen is sometimes represented as H, helium is sometimes represented as He, boron is sometimes represented as B, and boron fluoride is sometimes represented as BF₂Silicon nitride as SiN and silicon oxide as SiO₂Silicon oxynitride is denoted as SiON, titanium as Ti, aluminum as Al, chromium as Cr, gold as Au, titanium nitride as TiN, aluminum as Al, tungsten as W, molybdenum as Mo, tantalum as Ta, tantalum nitride as TaN, platinum as Pt, palladium as Pd, nickel as Ni, iron as Fe, silver as Ag, copper as Cu, and tungsten silicon nitride as WSiN.

(embodiment mode 1)

First, the structure of the resistive element 100 according to embodiment 1 will be described with reference to fig. 1.

Fig. 1 is a plan view and a cross-sectional view of a resistance element 100 according to embodiment 1. More specifically, (a) of fig. 1 is a plan view of the resistor element 100, and (b) of fig. 1 is a cross-sectional view of the resistor element 100 taken along line I-I of fig. 1.

The resistive element 100 includes a substrate 101, a 1 st nitride semiconductor layer 102, a 2 nd nitride semiconductor layer 103, a two-dimensional electron gas layer 107, a 1 st electrode 113, a 2 nd electrode 114, and an insulating layer (hereinafter referred to as a 1 st insulating layer 106). The resistance element 100 has a resistance value stabilization structure. The resistance element 100 may also have an element separation layer 104.

The substrate 101 is composed of an Si substrate. The substrate 101 may be made of a substrate such as Sapphire, SiC, GaN, or AlN. The substrate 101 is a support member for mounting the following components.

The 1 st nitride semiconductor layer 102 is a layer provided above the substrate 101. In this embodiment, the 1 st nitride semiconductor layer 102 is provided in contact with the upper surface of the substrate 101. The 1 st nitride semiconductor layer 102 is composed of GaN. The 1 st nitride semiconductor layer 102 may be formed of, for example, InGaN, AlGaN, AlInGaN, or the like, which is a group III nitride semiconductor material.

The 2 nd nitride semiconductor layer 103 is a layer provided above the 1 st nitride semiconductor layer 102. In this embodiment, the 2 nd nitride semiconductor layer 103 is provided in contact with the upper surface of the 1 st nitride semiconductor layer 102. The 2 nd nitride semiconductor layer 103 is composed of AlGaN. The 2 nd nitride semiconductor layer 103 may be formed of, for example, GaN, InGaN, AlGaN, AlInGaN, or the like, which is a group III nitride semiconductor. The 2 nd nitride semiconductor layer 103 has a larger band gap than the 1 st nitride semiconductor layer 102.

As described above, the 2 nd nitride semiconductor layer 103 may be made of AlGaN, but is not limited thereto. The 2 nd nitride semiconductor layer 103 may be a stacked body including an AlGaN layer and other layers. For example, as another layer, the 2 nd nitride semiconductor layer 103 may include a cap (cap) layer composed of GaN on the uppermost layer (i.e., the face on the upper side of the 2 nd nitride semiconductor layer 103). For example, the 2 nd nitride semiconductor layer 103 may include a layer made of AlN in a layer in contact with the 1 st nitride semiconductor layer 102 (i.e., an interface between the 1 st nitride semiconductor layer 102 and the 2 nd nitride semiconductor layer 103) as another layer.

The two-dimensional electron gas layer 107 is a layer provided on the 1 st nitride semiconductor layer 102 side of the interface between the 1 st nitride semiconductor layer 102 and the 2 nd nitride semiconductor layer 103. As described above, when the 2 nd nitride semiconductor layer 103 is AlGaN and the 1 st nitride semiconductor layer 102 is GaN, the two-dimensional electron gas layer 107 having a high concentration of electrons is generated on the GaN layer side near the AlGaN/GaN interface due to piezoelectric polarization charges generated by the difference in lattice constants of AlGaN and GaN and the difference in band gap between AlGaN and GaN. The two-dimensional electron gas layer 107 provided between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view functions as a resistance element.

The element separation layer 104 is a layer for separating the resistance element 100 from elements other than the resistance element 100. The element separation layer 104 is obtained by inactivating a part of the 1 st nitride semiconductor layer 102 and the 2 nd nitride semiconductor layer 103 by ion implantation. As the ion, H, He, B or BF is used₂And the like.

The element isolation layer 104 may be a layer insulated by thermal oxidation.

The element separation layer 104 is provided so as to surround the 1 st nitride semiconductor layer 102. In this embodiment, the element separation layer 104 is provided so as to surround the 1 st nitride semiconductor layer 102, the 2 nd nitride semiconductor layer 103, and the two-dimensional electron gas layer 107.

The 1 st electrode 113 is an electrode provided above the 1 st nitride semiconductor layer 102 and ohmically connected to the two-dimensional electron gas layer 107. The 2 nd electrode 114 is an electrode which is disposed above the 1 st nitride semiconductor layer 102 and at a position spaced apart from the 1 st electrode 113 in a plan view, and is ohmically connected to the two-dimensional electron gas layer 107. In this embodiment, the 1 st electrode 113 and the 2 nd electrode 114 are provided in contact with the upper surface of the 2 nd nitride semiconductor layer 103. The two-dimensional electron gas layer 107 located between the two electrodes provided at an interval serves as a resistance element.

The 1 st electrode 113 and the 2 nd electrode 114 have a laminated structure including at least one of Ti and Al. The 1 st electrode 113 and the 2 nd electrode 114 may be formed of a laminated structure containing at least one of Cr and Au, for example. The 1 st electrode 113 and the 2 nd electrode 114 may have a laminated structure including at least two of Ti, Al, Cr, and Au, for example. The 1 st electrode 113 and the 2 nd electrode 114 may have the same laminated structure or different laminated structures.

The 1 st insulating layer 106 is in contact with the upper surface of the 2 nd nitride semiconductor layer 103, and is provided between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view. In addition, the region where the 1 st insulating layer 106 is provided is not limited to between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view. As shown in fig. 1 (a), the 1 st insulating layer 106 may be provided so as to surround the 1 st electrode 113 and the 2 nd electrode 114, respectively, in a plan view. As shown in fig. 1 (b), the 1 st insulating layer 106 is not provided and an opening is provided above the 1 st electrode 113 and the 2 nd electrode 114. Therefore, the top surfaces of the 1 st electrode 113 and the 2 nd electrode 114 are exposed.

The 1 st insulating layer 106 is made of SiN. The 1 st insulating layer 106 may be made of, for example, SiO₂SiON, AlN, etc.

Further, over the 1 st insulating layer 106 between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view, a conductive layer is not disposed. Further, the conductive layer may not be disposed in a region above the 2 nd nitride semiconductor layer 103 and between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view.

Here, the conductive layer is, for example, a conductive member such as a gate electrode in a field effect transistor, or a wiring layer for supplying power to the 1 st electrode 113 and the 2 nd electrode 114. If such a conductive layer is disposed above the 1 st insulating layer 106 between the 1 st electrode 113 and the 2 nd electrode 114, an electric field is generated around the conductive layer, and thus the resistance value of the two-dimensional electron gas layer 107 changes and becomes unstable. In this embodiment, since such a conductive layer is not provided, the resistance value of the two-dimensional electron gas layer 107 is less likely to change. That is, the resistance element 100 exhibiting a stable resistance value with little variation can be provided.

The resistance value stabilizing structure functions to make the resistance value of the resistance element constant. By providing the resistance value stabilizing structure, the resistance value of the two-dimensional electron gas layer 107 is further less likely to change.

Further, the resistance value stabilizing structure will be described in detail below using modifications of embodiment 1.

(modification 1 of embodiment 1)

In the present modification, the resistance value stabilizing structure is a structure in which the composition ratio Si/N of the 1 st insulating layer made of SiN is 1.1 or more and 2.3 or less. In this modification, the components common to those of embodiment 1 are not described in detail.

First, problems that may occur in the resistive element 100 of embodiment 1 will be described with reference to fig. 2A and 2B.

Fig. 2A is a cross-sectional view of the resistive element 100 according to embodiment 1 before and after voltage application. More specifically, (a) of fig. 2A is a cross-sectional view before voltage application, and (b) of fig. 2A is a cross-sectional view after voltage application. As shown in fig. 2A (a), a surface level 108 causing electron traps, such as an oxide layer or defects, is formed on the surface of the 2 nd nitride semiconductor layer 103 (more specifically, at the interface between the 2 nd nitride semiconductor layer 103 and the 1 st insulating layer 106). When a certain voltage is applied between the 1 st electrode 113 and the 2 nd electrode 114, electrons flow in the two-dimensional electron gas layer 107 due to the potential difference. At this time, electrons in the two-dimensional electron gas layer 107 are accelerated by an electric field generated by voltage application, and the electrons may be trapped by the surface level 108 (see fig. 2A (b)). Since the trapped electrons 109 deplete the underlying two-dimensional electron gas layer 107, the carrier concentration of the two-dimensional electron gas layer 107 decreases.

Fig. 2B is a conceptual diagram showing current-voltage characteristics before and after voltage application of the resistive element 100 according to embodiment 1. As described above, the carrier concentration of the two-dimensional electron gas layer 107 decreases by the voltage application, and the resistance value of the resistance element 100 may increase.

Therefore, in the present modification, a resistance value stabilizing structure, which is a structure relating to the insulating layer, is provided.

Fig. 3 is a cross-sectional view of the resistance element 100a according to modification 1 of embodiment 1 and a diagram showing a resistance value change rate. More specifically, (a) of fig. 3 is a cross-sectional view of the resistance element 100a, and corresponds to (b) of fig. 1. Fig. 3 (b) is a graph showing the relationship between the resistance change rate when 50V is applied to the resistive element 100a and the composition ratio Si/N of the 1 st insulating layer 106 a.

The resistance element 100a of modification 1 includes a substrate 101, a 1 st nitride semiconductor layer 102, a 2 nd nitride semiconductor layer 103, an element separation layer 104, a 1 st insulating layer 106a, a two-dimensional electron gas layer 107, a 1 st electrode 113, and a 2 nd electrode 114. The resistance element 100a has a resistance value stabilization structure. In the resistive element 100a, a conductive layer is not disposed over the 1 st insulating layer 106a between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view.

The 1 st insulating layer 106a of the present modification is made of silicon nitride (SiN). The composition ratio Si/N of the 1 st insulating layer 106a at the interface between the 1 st insulating layer 106a and the 2 nd nitride semiconductor layer 103 is 1.1 or more and 2.3 or less. For example, in a region within 10nm from the interface, the composition ratio Si/N of the 1 st insulating layer 106a is 1.1 or more and 2.3 or less. The resistance value stabilizing structure of the present modification example is a structure in which the 1 st insulating layer 106a has the above-described structure.

Here, the resistance value fluctuation rate is a value indicating a fluctuation rate of the resistance value before and after voltage application. As shown in FIG. 3 (b), if Si/N is increased, the resistance value fluctuation ratio is suppressed. This will be explained as follows. By making Si of SiN excessive, many Si dangling bonds (dangling bonds) exist in SiN, and the Si dangling bonds acquire oxygen of a surface oxide layer which is one cause of the surface level 108, so that the surface level 108 is eliminated. By eliminating the surface level 108, generation of the trapped electrons 109 as shown in fig. 2A is suppressed, and the resistance value fluctuation rate is suppressed.

Further, by setting Si/N to 1.1 or more, the resistance value fluctuation rate is sufficiently lower than 20%. By setting the resistance change rate to 20% or less, the required specifications of the product can be sufficiently satisfied. Further, the resistance change rate can be made 10% or less by making Si/N1.2 or more, and can be made 5% or less by making Si/N1.5 or more. Therefore, the requirement specification of a product with higher difficulty can be fully met.

Here, a field effect transistor 200 formed on the same substrate (substrate 101) as the resistance element 100a of the present modification will be described. As described in the background art, an integrated circuit including an FET and a resistance element is known. Fig. 4A is a plan view and a cross-sectional view of a field effect transistor 200 in which a resistor element 100a is formed on the same substrate (substrate 101) as that of modification 1 of embodiment 1. More specifically, (a) of fig. 4A is a plan view of the field effect transistor 200, and (b) of fig. 4A is a cross-sectional view of the field effect transistor 200 taken along line IV-IV of fig. 4A.

The field effect transistor 200 includes a substrate 101, a 1 st nitride semiconductor layer 102, a 2 nd nitride semiconductor layer 103, a two-dimensional electron gas layer 107, a source electrode 110, a gate electrode 111, a drain electrode 112, a 1 st insulating layer 106a, a 2 nd insulating layer 126, and an element separation layer 104.

For example, the components given the same reference numerals may be formed at the same time in the resistance element 100a and the field effect transistor 200.

In the field effect transistor 200, the 1 st insulating layer 106a is provided in contact with the upper surface of the 2 nd nitride semiconductor layer 103. A source electrode 110 and a drain electrode 112 are provided in the opening of the 1 st insulating layer 106 a. The source electrode 110 and the drain electrode 112 are electrodes that are ohmically connected to the two-dimensional electron gas layer 107. Between the source electrode 110 and the drain electrode 112, a gate electrode 111 forming a schottky junction with the 2 nd nitride semiconductor layer 103 is provided. The gate electrode 111 and the 2 nd nitride semiconductor layer 103 may be a pn junction. Further, a gate insulating layer may be provided. A gate insulating layer may be interposed between the gate electrode 111 and the 2 nd nitride semiconductor layer 103 to constitute an MIS (metal-insulator-semiconductor) structure.

Further, the 2 nd insulating layer 126 is provided over the 1 st insulating layer 106a, the source electrode 110, the gate electrode 111, and the drain electrode 112. The 2 nd insulating layer 126 is made of SiN. The 2 nd insulating layer 126 may be made of, for example, SiO₂SiON, AlN, etc. Here, the 2 nd insulating layer 126 and the 1 st insulating layer 106a may also be the same material and the same composition, but are not limited thereto.

Fig. 4A (b) shows a path of a gate-drain leakage current of the field effect transistor 200. The path of the leak current includes a path from the drain electrode 112 to the gate electrode 111 through the two-dimensional electron gas layer 107, and a path from the drain electrode 112 to the gate electrode 111 through the 1 st insulating layer 106 a.

Here, fig. 4B is a diagram showing a relationship between the resistivity and the composition ratio Si/N of the 1 st insulating layer 106a in modification 1 of embodiment 1. If Si/N becomes large, the resistivity decreases. Therefore, if Si/N is too large, leakage current through the 1 st insulating layer 106a increases, and reverse leakage between the gate and the drain increases. Here, by setting Si/N to 2.3 or less, the resistivity can be made 1.7X 10²Omega cm or more. This makes it possible to reduce the amount of current flowing through the 1 st insulating layer 106a in the reverse leakage between the gate and the drain to 10% or less of the total amount of leakage current (the sum of the path through the two-dimensional electron gas layer 107 and the path through the 1 st insulating layer 106 a). Namely, the required specifications of the product can be fully satisfied. Further, by setting Si/N to 2.0 or less, the resistivity can be set to 3.0 × 10²Omega cm or more, and further, by setting Si/N to 1.8 or less, the resistivity can be made 4.0X 10²Omega cm or more. Therefore, the requirement specification of a product with higher difficulty can be fully met.

With the above structure, the surface level is eliminated by the Si dangling bond, and thus the resistance value of the two-dimensional electron gas layer 107 is not easily changed. That is, the resistance element 100a exhibiting a stable resistance value with little variation can be provided.

Further, by setting the composition ratio Si/N to the above ratio, the required specifications of a difficult product can be sufficiently satisfied.

(modification 2 and modification 3 of embodiment 1)

In modification 1 of embodiment 1, the resistance value stabilizing structure is a structure in which the composition ratio Si/N of the insulating layer made of SiN is 1.1 or more and 2.3 or less, but is not limited thereto.

In modification 2, the resistance value stabilizing structure has a 1 st hole injection electrode. In modification 3, the resistance value stabilizing structure has a 1 st hole injection electrode and a 2 nd hole injection electrode. In this modification, the components common to embodiment 1 and modification 1 are not described in detail.

Fig. 5 is a cross-sectional view of a resistive element 100b according to modification 2 of embodiment 1 and a resistive element 100c according to modification 3 of embodiment 1. More specifically, (a) of fig. 5 is a cross-sectional view of the resistance element 100b according to modification 2 of embodiment 1. Fig. 5 (b) is a cross-sectional view of the resistance element 100c according to modification 3 of embodiment 1.

First, a resistance element 100b according to modification 2 will be described with reference to fig. 5 (a).

The resistance element 100b of modification 2 includes the constituent elements included in the resistance element 100 of embodiment 1 and the 1 st hole injection electrode 115. In the resistance element 100b of modification 2, a conductive layer is not disposed above the 1 st insulating layer 106 between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view.

The 1 st hole injection electrode 115 is provided in contact with the upper surface of the 2 nd nitride semiconductor layer 103 on the 1 st electrode 113 side between the 1 st electrode 113 and the 2 nd electrode 114. In the present modification, as shown in fig. 5 (a), the 1 st hole injection electrode 115 is interposed between the 2 nd nitride semiconductor layer 103 and a part of the 1 st electrode 113. The 1 st hole injection electrode 115 is electrically connected to the 1 st electrode 113.

Further, the 1 st hole injection electrode 115 is made of p-type GaN. The 1 st hole injection electrode 115 may be formed of, for example, InGaN, AlGaN, AlInGaN, or the like, which is a p-type group III nitride semiconductor. The resistance value stabilizing structure of the present modification is a structure in which the 1 st hole injection electrode 115 has the above-described structure.

The 1 st hole injection electrode 115 injects holes into the 2 nd nitride semiconductor layer 103 when the 1 st electrode 113 is at a high potential with respect to the 2 nd electrode 114.

Specifically, the following is made. By making the potential of the 1 st electrode 113 higher than the potential of the 2 nd electrode 114, a current flows from the 1 st electrode 113 toward the 2 nd electrode 114. Thus, holes are injected from the 1 st hole injection electrode 115, and the holes can eliminate the electrons 109 trapped by the surface level of the 2 nd nitride semiconductor layer 103.

As described above, the trapped electrons 109 can cause an increase in the resistance value of the two-dimensional electron gas layer 107.

With the above configuration, the trapped electrons 109 can be eliminated, and therefore the resistance value of the two-dimensional electron gas layer 107 is not easily changed. That is, the resistance element 100b exhibiting a stable resistance value with little variation can be provided.

In the resistive element 100b according to the present modification, the resistive element 100b may be used so that the 1 st electrode 113 is supplied with a higher potential than the 2 nd electrode 114. Thus, holes are injected from the 1 st hole injection electrode 115, electrons 109 trapped at the surface level of the 2 nd nitride semiconductor layer 103 can be eliminated, and the resistance element 100b exhibiting a stable resistance value with little variation can be obtained.

Next, a resistance element 100c according to modification 3 will be described with reference to fig. 5 (b).

The resistance element 100c of modification 3 includes the components of the resistance element 100 of embodiment 1, the 1 st hole injection electrode 115, and the 2 nd hole injection electrode 116. In the resistance element 100c of modification 3, a conductive layer is not disposed above the 1 st insulating layer 106 between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view.

The 1 st hole injection electrode 115 of modification 3 has the same structure as the 1 st hole injection electrode 115 of modification 2.

The 2 nd hole injection electrode 116 is provided in contact with the upper surface of the 2 nd nitride semiconductor layer 103 on the 2 nd electrode 114 side between the 1 st electrode 113 and the 2 nd electrode 114. In the present modification, as shown in fig. 5 (b), the 2 nd hole injection electrode 116 is interposed between the 2 nd nitride semiconductor layer 103 and a part of the 2 nd electrode 114. The 2 nd hole injection electrode 116 is electrically connected to the 2 nd electrode 114.

Further, the 2 nd hole injection electrode 116 is made of p-type GaN. The 2 nd hole injection electrode 116 may be formed of, for example, InGaN, AlGaN, AlInGaN, or the like, which is a p-type group III nitride semiconductor. The resistance value stabilizing structure of the present modification is a structure in which the 1 st hole injection electrode 115 and the 2 nd hole injection electrode 116 have the above-described structures.

The 2 nd hole injection electrode 116 injects holes into the 2 nd nitride semiconductor layer 103 when the 2 nd electrode 114 is at a high potential with respect to the 1 st electrode 113.

In this modification, holes are injected from the 1 st hole injection electrode 115 by setting the potential of the 1 st electrode 113 higher than the potential of the 2 nd electrode 114, and holes are injected from the 2 nd hole injection electrode 116 by setting the potential of the 2 nd electrode 114 higher than the 1 st electrode 113. In either case, the injected holes can eliminate the electrons 109 trapped by the surface level of the 2 nd nitride semiconductor layer 103. That is, hole injection is performed from two electrodes (the 1 st electrode 113 and the 2 nd electrode 114).

With the above configuration, the trapped electrons 109 can be eliminated, and thus the resistance value of the two-dimensional electron gas layer 107 is less likely to change.

That is, the resistance element 100c exhibiting a stable resistance value with little variation can be provided.

In the resistance element 100c of the present modification, hole injection is performed from two electrodes, and the resistance element 100c can be used as an element for causing a current to flow in both directions.

(modification 4 and modification 5 of embodiment 1)

The resistance value stabilizing structure is not limited to the structure described in embodiment 1 and the modifications.

In modification 4, the resistance value stabilizing structure has the 1 st electron extracting electrode. In modification 5, the resistance value stabilizing structure has a 1 st electron extracting electrode and a 2 nd electron extracting electrode. In this modification, the components common to embodiment 1 and each modification are not described in detail.

Fig. 6 is a cross-sectional view of a resistance element 100d according to modification 4 of embodiment 1 and a resistance element 100e according to modification 5 of embodiment 1. More specifically, (a) of fig. 6 is a cross-sectional view of the resistance element 100d according to modification 4 of embodiment 1. Fig. 6 (b) is a cross-sectional view of the resistance element 100e according to modification 5 of embodiment 1.

First, a resistance element 100d according to modification 4 will be described with reference to fig. 6 (a).

The resistance element 100d of modification 4 includes the constituent elements included in the resistance element 100 of embodiment 1 and the 1 st electron extracting electrode 117. In the resistance element 100d of modification 4, a conductive layer is not disposed above the 1 st insulating layer 106 between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view.

The 1 st electron extracting electrode 117 is provided in contact with the upper surface of the 2 nd nitride semiconductor layer 103 on the 1 st electrode 113 side between the 1 st electrode 113 and the 2 nd electrode 114. In the present modification, as shown in fig. 6 (a), the 1 st electron extraction electrode 117 is interposed between the 2 nd nitride semiconductor layer 103 and a part of the 1 st electrode 113. The 1 st electron extraction electrode 117 is electrically connected to the 1 st electrode 113.

Further, the 1 st electron extraction electrode 117 forms a schottky junction with the 2 nd nitride semiconductor layer 103. The 1 st electron extracting electrode 117 is formed of a laminated structure including Ni. The 1 st electron extracting electrode 117 may have a laminated structure including at least one of 1 kind of Ti, TiN, Hf, Pd, and Pt, for example. The resistance value stabilizing structure of the present modification is a structure in which the 1 st electron extracting electrode 117 has the above-described structure.

The 1 st electron extraction electrode 117 extracts electrons from the 2 nd nitride semiconductor layer 103 when the 1 st electrode 113 is at a high potential with respect to the 2 nd electrode 114.

Specifically, the following is made. By making the potential of the 1 st electrode 113 higher than the potential of the 2 nd electrode 114, a current flows from the 1 st electrode 113 toward the 2 nd electrode 114. Thus, the 1 st electron extraction electrode 117 forming the schottky junction can extract the electrons 109 trapped by the surface level.

As described above, the trapped electrons 109 can cause an increase in the resistance value of the two-dimensional electron gas layer 107.

With the above configuration, the trapped electrons 109 can be extracted, and therefore the resistance value of the two-dimensional electron gas layer 107 is less likely to change. That is, the resistance element 100d exhibiting a stable resistance value with little variation can be provided.

Next, a resistance element 100e according to modification 5 will be described with reference to fig. 6 (b).

The resistance element 100e of modification 5 includes the constituent elements of the resistance element 100 of embodiment 1, the 1 st electron extraction electrode 117, and the 2 nd electron extraction electrode 118. In the resistance element 100e of modification 5, a conductive layer is not disposed above the 1 st insulating layer 106 between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view.

The 1 st electron extracting electrode 117 of modification 5 has the same configuration as the 1 st electron extracting electrode 117 of modification 4.

The 2 nd electron extracting electrode 118 is provided in contact with the upper surface of the 2 nd nitride semiconductor layer 103 on the 2 nd electrode 114 side between the 1 st electrode 113 and the 2 nd electrode 114. In the present modification, as shown in fig. 6 (b), the 2 nd electron extraction electrode 118 is interposed between the 2 nd nitride semiconductor layer 103 and a part of the 2 nd electrode 114. The 2 nd electron extracting electrode 118 is electrically connected to the 2 nd electrode 114.

The 2 nd electron extracting electrode 118 has a laminated structure including Ni. The 2 nd electron extracting electrode 118 may have a laminated structure including at least one of 1 kind of Ti, TiN, Hf, Pd, and Pt, for example. The resistance value stabilizing structure of the present modification is a structure in which the 1 st electron extracting electrode 117 and the 2 nd electron extracting electrode 118 have the above-described structures.

The 2 nd electron extracting electrode 118 extracts electrons from the 2 nd nitride semiconductor layer 103 when the 2 nd electrode 114 is at a high potential with respect to the 1 st electrode 113.

In the present modification, the 1 st electron extracting electrode 117 extracts electrons by setting the potential of the 1 st electrode 113 to be higher than the potential of the 2 nd electrode 114, and the 2 nd electron extracting electrode 118 extracts electrons by setting the potential of the 2 nd electrode 114 to be higher than the 1 st electrode 113.

With the above configuration, the trapped electrons 109 can be extracted, and therefore the resistance value of the two-dimensional electron gas layer 107 is less likely to change.

That is, the resistance element 100e exhibiting a stable resistance value with little variation can be provided.

(modification 6 of embodiment 1)

The resistance value stabilizing structure is not limited to the structure described in embodiment 1 and the modifications.

In modification 6, the resistance value stabilizing structure has a stress buffer layer. In this modification, the components common to embodiment 1 and each modification are not described in detail.

Fig. 7A is a cross-sectional view of a resistance element 100f according to modification 6 of embodiment 1. Fig. 7A shows stress P applied from the outside.

The resistance element 100f of modification 6 includes the constituent elements included in the resistance element 100 of embodiment 1 and a stress relaxation layer 119. In the resistance element 100f of modification 6, a conductive layer is not disposed above the 1 st insulating layer 106 between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view.

The stress buffer layer 119 is a layer provided over the 1 st insulating layer 106. The planar shape of the stress buffer layer 119 may coincide with the planar shape of the 1 st insulating layer 106. The stress buffer layer 119 is a layer for relaxing stress from the outside. The resistance value stabilizing structure of the present modification is a structure in which the stress buffer layer 119 has the above-described structure.

Here, stress applied to the resistance element 100f from the outside is described. In the process of manufacturing the resistance element 100f, for example, when forming a sealing material for semiconductor chip assembly, stress is applied to the resistance element 100f from the outside. The influence of the stress on the current-voltage characteristics will be described with reference to fig. 7B.

Fig. 7B is a conceptual diagram illustrating current-voltage characteristics before and after stress is applied from the outside to the resistive element 100f according to modification 6 of embodiment 1. In the present modification, the two-dimensional electron gas layer 107 generated on the GaN layer (1 st nitride semiconductor layer 102) side of the AlGaN (2 nd nitride semiconductor layer 103)/GaN (1 st nitride semiconductor layer 102) interface is caused by piezoelectric polarization charges. Therefore, if this stress is applied, the carrier concentration changes, and the resistance value of the two-dimensional electron gas layer 107 changes.

The stress buffer layer 119 is made of polyimide. The stress buffer layer 119 may be made of, for example, a fluorine-based resin, a BCB (benzocyclobutene) resin, a photosensitive insulating layer, or the like. The stress relaxation layer 119 may be made of a material having a sufficient degree of elasticity in order to relax the stress P from the outside. The resistance value stabilizing structure of the present modification is a structure in which the stress buffer layer 119 has the above-described structure.

With the above configuration, stress from the outside is relaxed, and therefore, it is possible to suppress a change in the carrier concentration of the two-dimensional electron gas layer 107 due to the stress.

That is, the resistance element 100f exhibiting a stable resistance value with little variation can be provided.

(modification 7 of embodiment 1)

The resistance value stabilizing structure is not limited to the structure described in embodiment 1 and the modifications.

In modification 7, the resistance value stabilizing structure is a structure having an element separation layer containing inactive ions provided so as to surround the 1 st nitride semiconductor layer. In this modification, the components common to embodiment 1 and each modification are not described in detail.

First, problems that may occur in the resistive element 100 of embodiment 1 will be described with reference to fig. 8A and 8B.

Fig. 8A is a diagram illustrating movement of the inactive ions in the resistance element 100 according to embodiment 1. More specifically, (a) of fig. 8A is a plan view of the resistance element 100. Fig. 8A (b) is a cross-sectional view showing a cross-section of the resistive element 100 before the migration of the inactive ions along line VIII-VIII in fig. 8A (a). Fig. 8A (c) is a cross-sectional view showing the resistive element 100 after the migration of the inactive ions along line VIII-VIII in fig. 8A (a). In fig. 8A (c), the direction M of movement of the inactive ions is indicated by an arrow.

The inactive ions implanted for element separation may be moved by heat treatment or the like. When the moved inactive ions reach the two-dimensional electron gas layer 107, a region 120 in which the inactive ions have moved is formed in the resistance element 100. Since the carriers in the two-dimensional electron gas layer 107 are inactivated by the moved inactive ions, the region of the resistance element functioning as a resistance component is reduced.

Fig. 8B is a conceptual diagram illustrating current-voltage characteristics before and after movement of the inactive ions in the resistive element 100 according to embodiment 1. As described above, the carrier concentration of the two-dimensional electron gas layer 107 decreases due to the movement of the inactive ions, and thus the resistance value of the resistance element 100 may increase.

Therefore, in the present modification, a resistance value stabilizing structure is provided as a structure relating to the element separation layer.

Fig. 9 is a plan view and a cross-sectional view of a resistance element 100g according to modification 7 of embodiment 1. More specifically, (a) of fig. 9 is a plan view of the resistance element 100g, and (b) of fig. 9 is a sectional view of the resistance element 100g showing a line IX-IX of fig. 9 (a).

The resistive element 100g of modification 7 includes a substrate 101, a 1 st nitride semiconductor layer 102, a 2 nd nitride semiconductor layer 103, an element separation layer 104g, a 1 st insulating layer 106g, a two-dimensional electron gas layer 107, a 1 st electrode 113, and a 2 nd electrode 114. The resistance element 100g has a resistance value stabilization structure. In the resistive element 100g, a conductive layer is not disposed over the 1 st insulating layer 106g between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view.

The element separation layer 104g is a layer containing inactive ions, which is provided so as to surround the 1 st nitride semiconductor layer 102 in a plan view. Further, a distance d1 between the upper surface of the element separation layer 104g and the upper surface of the substrate 101 is smaller than a distance d2 between the lower surface of the two-dimensional electron gas layer 107 and the upper surface of the substrate 101. That is, in this modification, the element separation layer 104g and the two-dimensional electron gas layer 107 do not contact each other. The resistance value stabilizing structure of the present modification is a structure in which the element separation layer 104g has the above-described structure.

The 1 st insulating layer 106g may be configured to cover the upper surface of the 2 nd nitride semiconductor layer 103 and the side surfaces of the 1 st nitride semiconductor, the two-dimensional electron gas layer 107, and the 2 nd nitride semiconductor layer 103.

The resistance element 100g of this modification is produced by the following example. First, the 1 st nitride semiconductor layer 102 and the 2 nd nitride semiconductor layer 103 are sequentially stacked on the upper surface of the substrate 101 (in this case, the two-dimensional electron gas layer 107 is also formed). Next, a part of the 1 st nitride semiconductor layer 102 and the 2 nd nitride semiconductor layer 103 is etched. Specifically, the 1 st nitride semiconductor layer 102 and the 2 nd nitride semiconductor layer 103 are etched halfway from the 2 nd nitride semiconductor layer 103 to the 1 st nitride semiconductor layer 102 so that the two-dimensional electron gas layer 107 is exposed at the side surfaces. At this time, in the 1 st nitride semiconductor layer 102 and the 2 nd nitride semiconductor layer 103, a mesa (mesa) structure 122 is formed. Here, the 1 st nitride semiconductor layer 102 remaining without being etched is ion-implanted to inactivate the 1 st nitride semiconductor layer 102, thereby forming the element separation layer 104 g.

In the resistive element 100g, since the region in which ions are implanted (i.e., the element separation layer 104g) and the two-dimensional electron gas layer 107 are not in contact with each other, it is possible to suppress migration of inactive ions to the two-dimensional electron gas layer 107. That is, the resistance element 100g exhibiting a stable resistance value with little variation can be provided.

(modification 8 of embodiment 1)

The resistance value stabilizing structure is not limited to the structure described in embodiment 1 and the modifications.

In modification 8, the resistance value stabilizing structure has a high resistance layer. In this modification, the components common to embodiment 1 and each modification are not described in detail.

First, problems that may occur in the resistive element 100 of embodiment 1 will be described with reference to fig. 10A and 10B.

Fig. 10A is a diagram illustrating the resistance of the resistive element 100 according to embodiment 1. More specifically, (a) of fig. 10A is a plan view of the resistance element 100. Fig. 10A (b) is a cross-sectional view of the resistive element 100 taken along line X-X in fig. 10A (a).

At normal temperature, the current path of the resistive element 100 having the two-dimensional electron gas layer 107 as the resistive element is a path passing through one of the 1 st electrode 113 and the 2 nd electrode 114 and the two-dimensional electron gas layer 107 and the other of the 1 st electrode 113 and the 2 nd electrode 114.

However, for example, when the substrate 101 is an Si substrate, the resistance value of the substrate 101 decreases at a high temperature. Therefore, as a current path of the resistive element 100 having the two-dimensional electron gas layer 107 as a resistive element, a current path passing through one of the 1 st electrode 113 and the 2 nd electrode 114 and the substrate 101 and the other of the 1 st electrode 113 and the 2 nd electrode 114 may newly occur.

Fig. 10B is a conceptual diagram showing current-voltage characteristics of the resistive element 100 according to embodiment 1 at normal temperature and at high temperature. As described above, the following are the cases: the resistance value of the resistance element 100 at high temperature is lower than the resistance value of the resistance element 100 at normal temperature, and as a result, the current value of the resistance element 100 at high temperature is higher than the current value of the resistance element 100 at normal temperature.

Therefore, in the present modification, a resistance value stabilizing structure is provided as a structure relating to the high-resistance layer.

Fig. 11 is a cross-sectional view of a resistance element 100h according to modification 8 of embodiment 1. More specifically, fig. 11 is a view corresponding to fig. 1 (b).

The resistive element 100h according to this modification includes the components included in the resistive element 100 according to embodiment 1 and the high-resistance layer 123. In the resistance element 100h of the present modification, a conductive layer is not disposed above the 1 st insulating layer 106 between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view.

The high-resistance layer 123 is a layer provided between the substrate 101 and the 1 st nitride semiconductor layer 102. The high-resistance layer 123 has a higher resistivity than the substrate 101. The resistivity of the high-resistance layer 123 may be 1000 Ω cm or more, for example. The high-resistance layer 123 may be a layer having a band gap larger than that of the 1 st nitride semiconductor layer 102 (e.g., an AlGaN layer or an AlN layer), or may be a layer having a superlattice structure composed of AlN/AlGaN. The high-resistance layer 123 may be a layer in which a light element such as helium or hydrogen is implanted at a high acceleration into a region of the 1 st nitride semiconductor layer 102 on the substrate 101 side, or may be an insulating layer epitaxially grown on the upper surface of the substrate 101. The resistance value stabilizing structure of the present modification is a structure in which the high-resistance layer 123 has the above-described structure.

In this structure, even when the resistance of the substrate 101 is lowered at a high temperature, no current flows through the high-resistance layer 123, and thus variation in the resistance value of the resistive element 100h can be suppressed.

That is, the resistance element 100h exhibiting a stable resistance value with little variation can be provided.

(modification 9 of embodiment 1)

The resistance value stabilizing structure is not limited to the structure described in embodiment 1 and the modifications.

In modification 9, the resistance value stabilizing structure is a structure having a low-temperature characteristic resistance element portion. In this modification, the components common to embodiment 1 and each modification are not described in detail.

First, a description will be given of a background using a low-temperature characteristic resistance element portion.

As also shown in patent document 1, a resistive element having a two-dimensional electron gas layer as a resistive element has a characteristic that a resistance value increases greatly (that is, a temperature coefficient of the two-dimensional electron gas layer is large) with a temperature increase. This is because the mobility of the two-dimensional electron gas layer decreases as the temperature increases. Although there is no problem in the above-described increase in resistance value when a circuit configuration that skillfully utilizes such a variation is adopted, the above-described increase in resistance value becomes a problem when the circuit is simply used as a resistance element that exhibits a constant resistance value.

Next, a modified example for solving the problem will be described.

Fig. 12 is a plan view and a cross-sectional view of a resistance element 100i according to modification 9 of embodiment 1. More specifically, (a) of fig. 12 is a plan view of the resistor element 100i, and (b) of fig. 12 is a cross-sectional view of the resistor element 100i taken along line XII-XII of fig. 12 (a).

The resistance element 100i of the present modification includes the constituent elements included in the resistance element 100 of embodiment 1, the low-temperature-characteristic resistance element unit 300, and the two wiring layers 125. In the resistance element 100i of the present modification, a conductive layer is not disposed above the 1 st insulating layer 106 between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view.

The low-temperature-characteristic resistance element portion 300 is provided above the substrate 101. As shown in fig. 12, the low-temperature-characteristic resistive element portion 300 includes an element separation layer 104, a 1 st insulating layer 106, a thin-film resistive layer 124, a 3 rd electrode 130, and a 4 th electrode 131.

The thin-film resistive layer 124 is a layer provided above the element separation layer 104. The thin-film resistance layer 124 is made of a material having a smaller temperature coefficient than the two-dimensional electron gas layer 107. The thin-film resistor layer 124 is a metal resistor made of TiN, for example. The thin-film resistor layer 124 may be made of Al, Au, W, Ti, Mo, Ta, TaN, Pt, Pd, Ni, Cr, Fe, Ag, Cu, SiN, AlN, or the like. The thin-film resistor layer 124 may be a semiconductor resistor made of Si having a negative temperature coefficient. The thin-film resistor layer 124 may be made of, for example, SiN, WSiN, or the like having a high Si composition ratio. The width, thickness, and length of the thin-film resistive layer 124 are determined so as to have a desired resistance value. A 3 rd electrode 130 and a 4 th electrode 131 are stacked on the thin-film resistance layer 124.

The 3 rd electrode 130 and the 4 th electrode 131 are lead electrodes provided above the thin-film resistive layer 124. Between the 3 rd electrode 130 and the 4 th electrode 131, a space is left in a plan view. The 3 rd electrode 130 and the 4 th electrode 131 are electrically connected to the thin film resistance layer 124.

The 3 rd electrode 130 and the 4 th electrode 131 are made of a material having conductivity. The 3 rd electrode 130 and the 4 th electrode 131 may be made of, for example, metal. The 3 rd electrode 130 and the 4 th electrode 131 may have a laminated structure including at least 1 of Ti, Al, Cr, and Au, for example. In addition, the 3 rd electrode 130 and the 4 th electrode 131 may be composed of the same material, but are not limited thereto.

The 1 st insulating layer 106 is in contact with the upper surface of the element separation layer 104, and is provided between the 3 rd electrode 130 and the 4 th electrode 131 in a plan view. The 1 st insulating layer 106 is provided so as to surround the thin resistive layer 124, and the 3 rd and 4 th electrodes 130 and 131, respectively.

The temperature coefficient of the low-temperature-characteristic resistive element portion 300 configured as described above is smaller than the temperature coefficient of the two-dimensional electron gas layer 107 (the increase in the resistance value due to the temperature increase is small). Alternatively, the temperature coefficient of the low-temperature-characteristic resistive element portion 300 is negative (the resistance value decreases as the temperature increases).

The temperature coefficient of the low-temperature-characteristic resistive element portion 300 is smaller than the temperature coefficient of the two-dimensional electron gas layer 107. That is, the resistance value of the low-temperature-characteristic resistive element portion 300 is less likely to increase at high temperature than the resistance value of the two-dimensional electron gas layer 107.

The 1 st electrode 113 is connected to the 3 rd electrode 130, and the 2 nd electrode 114 is connected to the 4 th electrode 131. Specifically, the electrodes are connected by two wiring layers 125. For example, one of the two wiring layers 125 connects the 1 st electrode 113 and the 3 rd electrode 130, and the other connects the 2 nd electrode 114 and the 4 th electrode 131. In other words, in the present modification, the 1 st electrode 113, the two-dimensional electron gas layer 107, and the 2 nd electrode 114 are connected in parallel to the low-temperature-characteristic resistive element portion 300. Two wiring layers 125 may connect the electrodes across the top of the 1 st insulating layer 106. The two wiring layers 125 are provided separately.

The two wiring layers 125 are made of a material having conductivity. The two wiring layers 125 may be made of metal, for example. The two wiring layers 125 may have a laminated structure containing at least 1 of Al, Au, Ag, and Cu, for example. In addition, the two wiring layers 125 may be respectively composed of the same material, but are not limited thereto. The resistance value stabilizing structure of the present modification is a structure in which the low-temperature characteristic resistance element portion 300 has the above-described structure.

Thus, the combined resistance value of the resistance element of the two-dimensional electron gas layer 107 and the low-temperature-characteristic resistance element portion 300 is less likely to change even at a high temperature than the resistance value of the resistance element of the two-dimensional electron gas layer 107 alone.

That is, the resistance element 100i exhibiting a stable resistance value with little variation can be provided.

(modification 10 of embodiment 1)

The resistance value stabilizing structure is not limited to the structure described in embodiment 1 and the modifications.

In modification 10, the resistance value stabilizing structure relates to the structure of the 1 st electrode and the 2 nd electrode. In this modification, the components common to embodiment 1 and each modification are not described in detail.

Fig. 13 is a plan view and a cross-sectional view of a resistance element 100j according to modification 10 of embodiment 1. More specifically, (a) of fig. 13 is a plan view of the resistor element 100j, and (b) of fig. 13 is a cross-sectional view of the resistor element 100j taken along line XIII-XIII in fig. 13 (a).

The resistance element 100j according to modification 10 includes a substrate 101, a 1 st nitride semiconductor layer 102, a 2 nd nitride semiconductor layer 103, an element isolation layer 104, a 1 st insulating layer 106, a two-dimensional electron gas layer 107, a 1 st electrode 113j, and a 2 nd electrode 114 j. The resistance element 100j has a resistance value stabilization structure. In the resistance element 100j, a conductive layer is not disposed over the 1 st insulating layer 106 between the 1 st electrode 113j and the 2 nd electrode 114j in a plan view.

In the present modification, the 1 st electrode 113j and the 2 nd electrode 114j are buried in a part of the 1 st nitride semiconductor layer 102 from the upper surface of the 2 nd nitride semiconductor layer 103 so as to be in contact with the two-dimensional electron gas layer 107. In other words, the 1 st electrode 113j and the 2 nd electrode 114j are buried from the upper surface of the 2 nd nitride semiconductor layer 103 until reaching the two-dimensional electron gas layer 107.

In this case, the two-dimensional electron gas layer 107 between the 1 st electrode 113j and the 2 nd electrode 114j provided at an interval in a plan view also serves as a resistance element.

With this configuration, the contact resistance component that varies depending on the size of the 1 st electrode 113j and the 2 nd electrode 114j can be removed from the resistance components of the 1 st electrode 113j and the 2 nd electrode 114j, and the resistance value can be stabilized. The distance between the 1 st electrode 113j and the 2 nd electrode 114j is constant. The resistance value stabilizing structure of the present modification is a structure in which the 1 st electrode 113j and the 2 nd electrode 114j have the above-described structures.

Thus, the resistance value of the two-dimensional electron gas layer 107 is less likely to depend on the sizes of the 1 st electrode 113j and the 2 nd electrode 114 j.

That is, the resistance element 100j exhibiting a stable resistance value with little variation can be provided.

(modification 11 of embodiment 1)

The resistance value stabilizing structure is not limited to the structure described in embodiment 1 and the modifications.

In modification 11, the resistance value stabilizing structure relates to the structure of the 1 st insulating layer. In this modification, the components common to embodiment 1 and each modification are not described in detail.

Fig. 14 is a plan view and a cross-sectional view of a resistance element 100k according to modification 11 of embodiment 1. More specifically, (a) of fig. 14 is a plan view of the resistor element 100k, and (b) of fig. 14 is a cross-sectional view of the resistor element 100k showing the XIV-XIV line of fig. 14 (a).

The resistive element 100k includes a substrate 101, a 1 st nitride semiconductor layer 102, a 2 nd nitride semiconductor layer 103, an element isolation layer 104, a 1 st insulating layer 106k, a 2 nd insulating layer 126, a two-dimensional electron gas layer 107, a 1 st electrode 113, and a 2 nd electrode 114. The resistance element 100k has a resistance value stabilization structure. In the resistive element 100k, a conductive layer is not disposed over the 1 st insulating layer 106k between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view.

In the present modification, the 1 st insulating layer 106k is provided at a distance from each of the 1 st electrode 113 and the 2 nd electrode 114 in a plan view. That is, the 1 st insulating layer 106k does not contact the 1 st electrode 113 and the 2 nd electrode 114.

The 2 nd insulating layer 126 is provided above the 2 nd nitride semiconductor layer 103 to fill the gap between the 1 st insulating layer 106k and the 1 st and 2 nd electrodes 113 and 114. The 2 nd insulating layer 126 is provided so as to surround the 1 st electrode 113 and the 2 nd electrode 114 in plan view.

The 2 nd insulating layer 126 may be disposed over the 1 st insulating layer 106 k. As shown in fig. 14 (b), the opening is provided above the 1 st electrode 113 and the 2 nd electrode 114 without providing the 2 nd insulating layer 126. Therefore, the top surfaces of the 1 st electrode 113 and the 2 nd electrode 114 are exposed.

The 2 nd insulating layer 126 is made of SiN. The 2 nd insulating layer 126 may be made of, for example, SiO₂SiON, AlN, etc. Here, the 2 nd insulating layer 126 and the 1 st insulating layer 106k may be the same material and the same composition, but are not limited thereto. The resistance value stabilizing structure of the present modification example is a structure in which the 1 st insulating layer 106k has the above-described structure.

Here, a method for manufacturing the resistance element 100k of the present modification will be briefly described. In order to ohmic-connect the 1 st electrode 113 and the 2 nd electrode 114 to the two-dimensional electron gas layer 107, a heat treatment of about 500 ℃ is required. For example, when the 1 st electrode 113 and the 2 nd electrode 114 are in contact with the 1 st insulating layer 106k, the metal constituting the 1 st electrode 113 and the 2 nd electrode 114 may be thermally diffused into the 1 st insulating layer 106k during the heat treatment. When the metal is thermally diffused into the 1 st insulating layer 106k, there is a possibility that the reliability of the resistive element 100k is adversely affected by a short circuit between the 1 st electrode 113 and the 2 nd electrode 114, a breakdown withstand voltage drop of the 1 st insulating layer 106k, or the like. Therefore, in the method of manufacturing the resistive element 100k according to the present modification, the 1 st insulating layer 106k is formed so as not to contact the 1 st electrode 113 and the 2 nd electrode 114 as in the above-described configuration, and then the above-described heat treatment is performed. Then, a 2 nd insulating layer 126 is formed.

This suppresses diffusion of the metal into the 1 st insulating layer 106k by the heat treatment, and a highly reliable resistive element 100k can be obtained.

(embodiment mode 2)

Here, a power amplifier circuit using the resistive element according to embodiment 1 and each modification will be described. In the present embodiment, the components common to embodiment 1 and the modifications are not described in detail.

Fig. 15A is a circuit diagram showing a power amplifier circuit 500 according to embodiment 2. Fig. 15B is a diagram showing the temperature dependence of the gain of the power amplifier circuit 500 according to embodiment 2. In addition, the temperature in fig. 15B is the temperature of the power amplification circuit 500.

The power amplifier circuit 500 includes the resistive element 100 shown in embodiment 1, a field effect transistor 401 provided above a substrate 101 included in the resistive element 100, and a capacitor 403.

The field effect transistor 401 has a source electrode, a drain electrode, and a gate electrode. One of the 1 st electrode 113 and the 2 nd electrode 114 included in the resistive element 100 is electrically connected to the gate electrode, and the other is electrically connected to the drain electrode via the capacitor 403.

The power amplifier circuit 500 may include a gate terminal 404 and a drain terminal 405 connected to a gate electrode and a drain electrode of the field-effect transistor 401, and a resistor 402. In this embodiment, the resistance element 100 is a resistor 402 shown in fig. 15A.

The negative feedback circuit is explained here. A negative feedback circuit that attenuates an output signal by a feedback resistor and feeds back an input signal to an input side is used for stabilization of a high frequency circuit. In the negative feedback circuit, if the feedback resistance value becomes small, the stability of the power amplification circuit 500 increases, and the gain decreases.

In this embodiment, a negative feedback circuit including a resistor 402 and a capacitor 403 is connected to a gate terminal 404 and a drain terminal 405 of a field effect transistor 401 for a signal amplifier.

The power amplifier circuit 500 using a semiconductor has a reduced gain due to a reduction in carrier mobility at high temperatures. For example, in the circuit of the comparative example having a resistance with a smaller temperature coefficient than the resistance 402, as shown in fig. 15B, the gain drop at high temperature is large. However, the power amplifier circuit 500 includes the resistive element 100 including the two-dimensional electron gas layer 107 having a large temperature coefficient. Therefore, in the power amplifier circuit 500, the resistance value of the two-dimensional electron gas layer 107 increases at high temperature, and the feedback amount in the negative feedback circuit decreases, so that the gain drop at high temperature is alleviated.

(embodiment mode 3)

Here, a power amplifier circuit using the resistive element according to embodiment 1 and each modification will be described. In embodiment 2, the resistance element constitutes a negative feedback circuit, but is not limited thereto. In embodiment 3, the resistance element constitutes a bias circuit for applying a gate voltage of the field effect transistor and setting a drain current. In the present embodiment, the components common to embodiment 1 and the modifications are not described in detail.

Fig. 16A is a circuit diagram showing a power amplifier circuit 500a according to embodiment 3. Fig. 16B is a diagram showing the temperature dependence of the gate voltage of the field-effect transistor 406 and the temperature dependence of the drain current of the field-effect transistor 406, which are included in the power amplifier circuit 500a according to embodiment 3. More specifically, (a) of fig. 16B shows the temperature dependence of the gate voltage of the field-effect transistor 406, and (B) of fig. 16B shows the temperature dependence of the drain current of the field-effect transistor 406. In addition, the temperature in fig. 16B is the temperature of the power amplification circuit 500 a.

The power amplification circuit 500a has a field effect transistor 406 and a bias circuit. The power amplifier circuit 500a may have a 1 st gate bias terminal 407, a 2 nd gate bias terminal 408, a 1 st resistor 409, a 2 nd resistor 410, and a gate terminal 404a and a drain terminal 405a connected to a gate electrode and a drain electrode of the field effect transistor 406.

The bias circuit includes the resistance element 100 shown in embodiment mode 1. The bias circuit applies the gate voltage of the field effect transistor 406 to set the drain current.

The resistance element 100 is at least one of the 1 st resistor 409 and the 2 nd resistor 410.

The field effect transistor 406 is provided above the substrate 101 provided in the resistance element 100. The field effect transistor 406 has a source electrode, a drain electrode, and a gate electrode.

The 1 st gate bias terminal 407 is applied with a voltage higher than that of the 2 nd gate bias terminal 408, and one of the gate bias terminals may be grounded.

For example, a case where the 2 nd resistor 410 is the resistor element 100 and the temperature coefficient of the 1 st resistor 409 is smaller than that of the 2 nd resistor 410 will be described. In this case, as shown in fig. 16B, the gate voltage of the field-effect transistor 406 increases due to the temperature increase, and the drain current of the field-effect transistor 406 at a high temperature can be increased as compared with the case where the temperature coefficients of the two are equal.

For example, a case where the 1 st resistor 409 is the resistor element 100 and the temperature coefficient of the 1 st resistor 409 is larger than that of the 2 nd resistor 410 will be described. In this case, the gate voltage of the field-effect transistor 406 decreases due to the temperature rise, and the drain current of the field-effect transistor 406 at a high temperature can be reduced as compared with a case where the temperature coefficients of the two are equal.

With the above configuration, the drain current of the field effect transistor 406 can be easily controlled.

Further, the 1 st resistor 409 and the 2 nd resistor 410 may be the resistor element 100, respectively. In this case, the temperature coefficients of the 1 st resistor 409 and the 2 nd resistor 410 may be different.

(embodiment mode 4)

In embodiment 1 and the modifications, an example of a resistive element in which a conductive layer is not disposed above a 1 st insulating layer between a 1 st electrode and a 2 nd electrode in a plan view is shown. However, it is not limited thereto. Embodiment 4 is different from embodiment 1 in that the resistance element includes the conductive control layer. In the present embodiment, the components common to embodiment 1 and the modifications are not described in detail.

Fig. 17 is a plan view and a cross-sectional view of a resistance element 100m according to embodiment 4. More specifically, (a) of fig. 17 is a plan view of the resistor element 100m, and (b) of fig. 17 is a cross-sectional view of the resistor element 100m showing a line XVII-XVII in (a) of fig. 17.

The resistive element 100m includes a resistive element portion 1000 and a conductive control layer (hereinafter referred to as a 1 st conductive control layer 127). The resistance element 100m has a resistance value stabilization structure. The resistive element portion 1000 includes a substrate 101, a 1 st nitride semiconductor layer 102, a 2 nd nitride semiconductor layer 103, an element separation layer 104, a 1 st insulating layer 106, a two-dimensional electron gas layer 107, a 1 st electrode 113, and a 2 nd electrode 114.

The 1 st conductive control layer 127 is disposed above the insulating layer (1 st insulating layer 106) between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view. In this embodiment mode, the 1 st conductive control layer 127 is provided in contact with the insulating layer (the 1 st insulating layer 106). In addition, the 1 st conductive control layer 127 may be provided in a region which is located above the 2 nd nitride semiconductor layer 103 and between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view. Further, the length of the 1 st conductive control layer 127 in the direction in which the 1 st electrode 113 and the 2 nd electrode 114 are aligned in a plan view (length in the x-axis direction in fig. 17) is 1/2 or more of the interval of the 1 st electrode 113 and the 2 nd electrode 114. Further, as shown in fig. 17, the length of the 1 st conductive control layer 127 in this direction may be 3/4 or more of the interval between the 1 st electrode 113 and the 2 nd electrode 114.

The 1 st conductive control layer 127 controls the resistance value of the resistance element by applying an electric field to the two-dimensional electron gas layer 107 in accordance with a voltage supplied from the outside of the resistance element portion 1000. That is, the 1 st conductive control layer 127 can intentionally control the resistance value of the resistance element.

Fig. 18 is a diagram showing a state of generation of the two-dimensional electron gas layer 107 in a case where a potential is applied to the 1 st conductive control layer 127 of the resistive element 100m according to embodiment 4. More specifically, (a) of fig. 18 is a diagram showing a case where the 1 st conductive control layer 127 is applied with a positive potential, and (b) of fig. 18 is a diagram showing a case where the 1 st conductive control layer 127 is applied with a negative potential. For example, as shown in fig. 18 (a), when the 1 st conductive control layer 127 is applied with a positive potential, the conduction band ratio fermi level at the interface between the 1 st nitride semiconductor layer 102 and the 2 nd nitride semiconductor layer 103 is lowered, and more carriers are generated in the two-dimensional electron gas layer 107. In contrast, as shown in fig. 18 (b), when the 1 st conductive control layer 127 is given a negative potential, the energy band of each component is raised (that is, the energy level of each component is shifted to be higher), and the conduction band is located above the fermi level (higher energy side), so that carriers are reduced in the two-dimensional electron gas layer 107. In this way, by changing the potential applied to the 1 st conductive control layer 127, the resistance value of the two-dimensional electron gas layer 107 shows an arbitrary value.

That is, the resistance element 100m having a desired resistance value can be provided. The resistance element 100m of the present embodiment can also be referred to as a variable resistance element.

The 1 st conductive control layer 127 is supplied with a voltage from the outside of the resistive element portion 1000. For example, the 1 st conductive control layer 127 may be supplied with a fixed potential from the outside of the resistance element portion 1000, or may be supplied with a control potential from the outside of the resistance element portion 1000. The potential to which the 1 st conductive control layer 127 is given may also be a ground potential. In addition, the 1 st conductive control layer 127 is not supplied with a voltage from the 1 st electrode 113 and the 2 nd electrode 114.

In addition, the 1 st conductive control layer 127 of this embodiment is not a gate electrode of a field effect transistor. As described above, in the present embodiment, the 1 st conductive control layer 127 controls the resistance value of the resistance element by applying an electric field to the two-dimensional electron gas layer 107, but the resistance element 100m is not a normally-off field effect transistor because conduction between the 1 st electrode 113 and the 2 nd electrode 114 is not interrupted.

Further, since the 1 st conductive control layer 127 is disposed above the 1 st insulating layer 106, insulated from the 2 nd nitride semiconductor layer 103, the resistance element 100m is not a junction field effect transistor. Accordingly, the potential applied to the 1 st conductive control layer 127 for controlling the resistance value of the resistance element 100m may be small, and the resistance element 100m may be a variable resistance element which can be easily used in a control circuit.

In addition, the longer the length of the 1 st conductive control layer 127 in the arrangement direction of the 1 st electrode 113 and the 2 nd electrode 114 is, the larger the area of the 1 st conductive control layer 127 covering the two-dimensional electron gas layer 107 in a plan view is. Therefore, the longer the length of the 1 st conductive control layer 127 is, the more easily the electric field can be applied to the two-dimensional electron gas layer 107, and therefore the resistance value of the two-dimensional electron gas layer 107 can be more easily controlled.

The resistance value stabilizing structure according to the present embodiment may be the resistance value stabilizing structure described in each of the modifications of embodiment 1. In the present embodiment, for example, a potential is applied to the 1 st conductive control layer 127 to set the resistance value of the two-dimensional electron gas layer 107 to a desired value, and the resistance value stabilizing structure is configured to set the resistance value set to the desired value to be constant.

(modification 1 of embodiment 4)

In embodiment 4, an example in which the resistance element includes 1 conductive control layer is shown, but the present invention is not limited thereto. In this modification, the point that the resistance element includes a plurality of conductive control layers is different from embodiment 4. In this modification, the components common to those of embodiment 4 are not described in detail.

Fig. 19 is a plan view and a cross-sectional view of a resistance element 100n according to modification 1 of embodiment 4. More specifically, (a) of fig. 19 is a plan view of the resistor element 100n, and (b) of fig. 19 is a cross-sectional view of the resistor element 100n taken along the XIX-XIX line of fig. 19 (a).

The resistance element 100n includes the constituent elements of the resistance element 100m of embodiment 4, the 2 nd insulating layer 126, and the 2 nd conductive control layer 128.

The 2 nd insulating layer 126 is disposed over the 1 st insulating layer 106 and the 1 st conductive control layer 127. As shown in fig. 19, the 2 nd insulating layer 126 is provided in such a manner as to cover the 1 st conductive control layer 127. The 2 nd insulating layer 126 is provided so as to surround the 1 st electrode 113 and the 2 nd electrode 114 in plan view. As shown in fig. 19 (b), an opening is provided above the 1 st electrode 113 and the 2 nd electrode 114 without providing the 2 nd insulating layer 126. Therefore, the top surfaces of the 1 st electrode 113 and the 2 nd electrode 114 are exposed.

The 2 nd insulating layer 126 is made of SiN. The 2 nd insulating layer 126 may be made of, for example, SiO₂SiON, AlN, etc. Here, the 2 nd insulating layer 126 and the 1 st insulating layer 106 may be the same material and the same composition, but are not limited thereto.

The 2 nd conductive control layer 128 is disposed on the insulating layer (2 nd insulating layer 126) between the 1 st electrode 113 and the 2 nd electrode 114 in a plan view. Further, the length of the 2 nd conductive control layer 128 in the arrangement direction of the 1 st electrode 113 and the 2 nd electrode 114 (length in the x-axis direction in fig. 19) in a plan view is 1/2 or more of the interval of the 1 st electrode 113 and the 2 nd electrode 114. Further, the 1 st conductive control layer 127 and the 2 nd conductive control layer 128 may be arranged to overlap in a plan view.

The 2 nd conductive control layer 128 controls the resistance value of the resistance element by applying an electric field to the two-dimensional electron gas layer 107 in accordance with a voltage supplied from the outside of the resistance element portion 1000.

As described in embodiment 4, the resistance value of the two-dimensional electron gas layer 107 can have any value by changing the potentials applied to the 1 st conductive control layer 127 and the 2 nd conductive control layer 128.

That is, the resistance element 100n having a desired resistance value can be provided. The resistance element 100n of the present embodiment can also be referred to as a variable resistance element.

The potential applied to the 2 nd conductive control layer 128 may be substantially the same as or different from the potential applied to the 1 st conductive control layer 127.

Here, an example is shown in which the resistance element 100n and the field-effect transistor 200n of the present modification are provided on the same substrate (the substrate 101 in the present modification).

Fig. 20 is a plan view and a cross-sectional view of the resistance element 100n and the field-effect transistor 200n according to modification 1 of embodiment 4. More specifically, (a) of fig. 20 is a plan view of the resistance element 100n and the field effect transistor 200n, and (b) of fig. 20 is a cross-sectional view of a cross-section of the resistance element 100n and the field effect transistor 200n along the line XX to XX of fig. 20 (a).

The field effect transistor 200n of the present modification is provided above the substrate 101 provided in the resistance element 100 n. That is, the resistance element 100n and the field effect transistor 200n are monolithic (one chip) type semiconductors provided on the same substrate.

The field effect transistor 200n includes a substrate 101, a 1 st nitride semiconductor layer 102, a 2 nd nitride semiconductor layer 103, a two-dimensional electron gas layer 107, a source electrode 110, a gate electrode 111, a drain electrode 112, a 1 st insulating layer 106, a 2 nd insulating layer 126, an element separation layer 104, and a field plate (field plate) electrode 129.

Further, detailed description of the components included in the field effect transistor 200 shown in the modification 1 of embodiment 1 is omitted.

In the present modification, the resistance element 100n and the field effect transistor 200n are electrically separated by the element separation layer 104.

The field plate electrode 129 reduces electric field concentration, thereby improving the withstand voltage of the field effect transistor 200 n.

As shown in fig. 20, for example, the components given the same reference numerals may be formed at the same time in the resistance element 100n and the field-effect transistor 200 n.

The 1 st electrode 113 and the 2 nd electrode 114 of the resistive element 100n and the source electrode 110 and the drain electrode 112 of the field-effect transistor 200n may have the same stacked structure and may be formed simultaneously in the same step.

The 1 st conductive control layer 127 of the resistive element 100n and the gate electrode 111 of the field-effect transistor 200n may have the same stacked structure and may be formed simultaneously in the same step.

The No. 2 conductive control layer 128 of the resistive element 100n and the field plate electrode 129 of the field effect transistor 200n may have the same stacked structure and may be formed simultaneously in the same process.

In this way, the resistance element 100n and the field effect transistor 200n of the present modification can be provided on the same substrate. Further, since the components of the resistor element 100n and the field-effect transistor 200n can be formed simultaneously in the same step, the resistor element 100n and the field-effect transistor 200n can be manufactured easily.

(embodiment 5)

Here, a power amplifier circuit using the resistive element of embodiment 4 and modification 1 of embodiment 4 will be described. In this embodiment, the components common to embodiment 4 and modification 1 of embodiment 4 are not described in detail.

Fig. 21A is a circuit diagram showing a power amplifier circuit 500B according to embodiment 5, and fig. 21B is a diagram showing a temperature dependence of a gain of the power amplifier circuit 500B according to embodiment 5. In addition, the temperature in fig. 21B is the temperature of the power amplification circuit 500B.

The power amplifier circuit 500b includes the resistive element 100m shown in embodiment 4, a field effect transistor 411 provided above the substrate 101 included in the resistive element 100m, and a capacitor 413.

The field effect transistor 411 has a source electrode, a drain electrode, and a gate electrode. One of the 1 st electrode 113 and the 2 nd electrode 114 included in the resistive element 100m is electrically connected to the gate electrode, and the other is electrically connected to the drain electrode via the capacitor 413.

The power amplifier circuit 500b may further include a gate terminal 414 and a drain terminal 415 connected to the gate electrode and the drain electrode of the field-effect transistor 411, a voltage generation circuit 417, and a resistor 412. In this embodiment, the resistance element 100m is a resistor 412 shown in fig. 21A. The 1 st conductive control layer 127 included in the resistive element 100m is a conductive control layer 416.

The conductive control layer 416 is connected to a voltage generation circuit 417. The voltage generation circuit 417 has a negative temperature coefficient.

For example, the voltage generation circuit 417 includes a resistor 418 and a diode 419. Resistor 418 has one terminal connected to positive bias application terminal 420 and the other terminal connected to conductive control layer 416. The anode of the diode 419 is connected to the conductive control layer 416, and the cathode of the diode 419 is grounded.

In this embodiment, a negative feedback circuit including a resistor 412 and a capacitor 413 is connected to a gate terminal 414 and a drain terminal 415 of a field effect transistor 411 for a signal amplifier.

Here, in the circuit of the comparative example having a resistance with a smaller temperature coefficient than the resistance 412, as shown in fig. 21B, the gain drop at high temperature is large. However, in the power amplifier circuit 500b, similarly to the power amplifier circuit 500 of embodiment 2, the resistance value of the two-dimensional electron gas layer 107 included in the resistive element 100m increases at high temperature, and the feedback amount in the negative feedback circuit decreases, so that the gain drop at high temperature is alleviated.

Further, in the present embodiment, since the voltage generation circuit 417 has a negative temperature coefficient, the voltage applied to the conductive control layer 416 is decreased at a high temperature. This increases the resistance value of the two-dimensional electron gas layer 107, reduces the feedback amount in the negative feedback circuit, and alleviates the gain drop at high temperatures. Therefore, by using the resistor element 100m including the two-dimensional electron gas layer 107 having a large temperature coefficient for the resistor 412 of the negative feedback circuit and further changing the electric field applied to the two-dimensional electron gas layer 107 by the voltage generation circuit 417, it is possible to suppress a decrease in gain at high temperatures.

(embodiment mode 6)

Here, a power amplifier circuit using the resistive element of embodiment 4 and modification 1 of embodiment 4 will be described. In embodiment 5, the resistance element constitutes a negative feedback circuit, but is not limited thereto. In embodiment 6, the resistance element constitutes a bias circuit for applying a gate voltage of the field effect transistor and setting a drain current. In the present embodiment, the components common to embodiment 4 and the modifications are not described in detail.

Fig. 22A is a circuit diagram showing a power amplifier circuit 500c according to embodiment 6. Fig. 22B is a diagram showing a relationship between a control voltage and a drain current of the field-effect transistor 421 included in the power amplifier circuit 500c according to embodiment 6.

The power amplifier circuit 500c has a field effect transistor 421 and a bias circuit. The power amplifier circuit 500c may have a 1 st gate bias terminal 422, a 2 nd gate bias terminal 423, a 1 st resistor 424, a 2 nd resistor 427, a conductive control layer 425, a control terminal 426, and a gate terminal 414c and a drain terminal 415c connected to a gate electrode and a drain electrode of the field effect transistor 421.

The bias circuit includes the resistance element 100m shown in embodiment mode 4. The bias circuit applies a gate voltage of the field effect transistor 421 to set a drain current.

The resistance element 100m is at least one of the 1 st resistor 424 and the 2 nd resistor 427. In this embodiment, the 1 st resistor 424 is a resistor element 100 m. The 1 st conductive control layer 127 included in the resistive element 100m is a conductive control layer 425. The conductive control layer 425 is connected to the control terminal 426.

The field effect transistor 421 is provided above the substrate 101 included in the resistance element 100 m. The field effect transistor 421 has a source electrode, a drain electrode, and a gate electrode.

A voltage higher than that of the 2 nd gate bias terminal 423 is applied to the 1 st gate bias terminal 422, and one of the gate bias terminals may be grounded.

In this embodiment, as shown in fig. 22B, the resistance value of the 1 st resistor 424 changes due to a change in the voltage (control voltage) applied to the control terminal 426, the gate voltage of the field-effect transistor 421 changes, and the drain current changes. That is, the drain current of the field-effect transistor 421 can be controlled by controlling the voltage applied to the control terminal 426.

Here, the following conditions will be described. Specifically, the following is the case: the field effect transistor 421 is a depletion (normal on) type field effect transistor, and the 2 nd gate bias terminal 423 is given a negative potential. In this case, by applying a positive potential to the control terminal 426, the drain current value of the field-effect transistor 421 can be controlled.

In addition, the 2 nd resistor 427 may be a resistor element 100 m. At this time, the change in the drain current corresponding to the voltage applied to the control terminal 426 is of opposite polarity.

(embodiment 7)

Here, a power amplifier circuit using the resistive element of embodiment 4 and modification 1 of embodiment 4 will be described. In embodiment 6, the conductive control layer provided in the resistance element is connected to the control terminal, but the present invention is not limited thereto. In embodiment 7, the conductive control layer provided in the resistance element is connected to a voltage generation circuit having a positive temperature coefficient. In the present embodiment, the components common to embodiment 4 and the modifications are not described in detail.

Fig. 23A is a circuit diagram showing a power amplifier circuit 500d according to embodiment 7. Fig. 23B is a graph showing the temperature dependence of the gate voltage of the field-effect transistor 428 and the temperature dependence of the drain current of the field-effect transistor 428 in embodiment 7. In addition, the temperature in fig. 23B is the temperature of the power amplification circuit 500 d.

More specifically, (a) of fig. 23B shows the temperature dependence of the gate voltage of the field-effect transistor 428, and (B) of fig. 23B shows the temperature dependence of the drain current of the field-effect transistor 428.

The power amplification circuit 500d has a field effect transistor 428 and a bias circuit. The power amplifier circuit 500d may include a 1 st gate bias terminal 429, a 2 nd gate bias terminal 430, a 1 st resistor 431, a 2 nd resistor 433, a conductive control layer 432, a voltage generation circuit 434, and a gate terminal 444 and a drain terminal 445 connected to a gate electrode and a drain electrode of the field effect transistor 428.

The bias circuit includes the resistance element 100m shown in embodiment mode 4. The bias circuit applies a gate voltage to the field effect transistor 428 to set the drain current.

The resistance element 100m is at least one of the 1 st resistor 431 and the 2 nd resistor 433. In this embodiment, the 1 st resistor 431 is a resistor element 100 m. The 1 st conductive control layer 127 included in the resistive element 100m is a conductive control layer 432. The conductive control layer 432 is connected to a voltage generation circuit 434.

The voltage generation circuit 434 has a positive temperature coefficient. For example, the voltage generation circuit 434 includes a diode 436 and a resistor 437. The anode of the diode 436 is connected to the positive bias application terminal 435, and the cathode of the diode 436 is connected to the conductive control layer 432. One terminal of the resistor 437 is connected to the conductive control layer 432, and the other terminal is grounded.

A voltage higher than that of the 2 nd gate bias terminal 430 is applied to the 1 st gate bias terminal 429, and one of the gate bias terminals may be grounded.

The field effect transistor 428 is provided above the substrate 101 provided in the resistance element 100 m. The field effect transistor 428 has a source electrode, a drain electrode, and a gate electrode.

As shown in the power amplifier circuit 500a of embodiment 3, the drain current of the field effect transistor 428 can be easily controlled by controlling the temperature coefficients of the 1 st resistor 431 and the 2 nd resistor 433.

Further, in the present embodiment, since the voltage generation circuit 434 has a positive temperature coefficient, the voltage applied to the conductive control layer 432 rises at a high temperature. As a result, the resistance of the 1 st resistor 431 is lowered, and thus the gate voltage of the field-effect transistor 428 is raised as shown in fig. 23B. Here, a circuit of a comparative example in which the gate voltage is fixed will be described. For example, as shown in fig. 23B, in the circuit of the comparative example in which the gate voltage is fixed, the current drop at high temperature is large. In contrast, the field-effect transistor 428 of this embodiment can suppress a current drop at high temperatures.

In addition, the 2 nd resistor 433 may be a resistor element 100 m. In this case, the same effect can be obtained when the conductive control layer 432 is connected to a voltage generation circuit having a negative temperature coefficient.

(other embodiments)

The resistor element and the like of the present invention have been described above based on the embodiments and the modifications, but the present invention is not limited to the embodiments and the modifications. The present invention is not limited to the embodiments described above, and various modifications and other modifications may be made without departing from the spirit and scope of the present invention.

Specifically, the resistance value stabilization structure shown in modification 1 of embodiment 1 and the resistance value stabilization structure shown in modification 2 or 3 of embodiment 1 may be combined. In this case, by eliminating the surface energy level by the Si dangling bond and eliminating the trapped electrons, the resistance value of the two-dimensional electron gas layer is less likely to change. Therefore, a resistance element exhibiting a stable resistance value with little variation can be further provided.

As another specific example, a resistance value stabilizing structure in which the resistance value stabilizing structure shown in modification 1 of embodiment 1 and the resistance value stabilizing structure shown in modification 4 or modification 5 of embodiment 1 are combined may be used. In this case, by eliminating the surface level by the Si dangling bond and extracting the trapped electrons, the resistance value of the two-dimensional electron gas layer is less likely to change. Therefore, a resistance element exhibiting a stable resistance value with little variation can be further provided.

In embodiments 2 and 3, an example in which the power amplifier circuit includes the resistance element 100 of embodiment 1 is shown, but the present invention is not limited thereto. For example, the power amplifier circuits according to embodiments 2 and 3 may include the resistance elements according to the modifications of embodiment 1.

In embodiments 5, 6, and 7, examples in which the power amplifier circuit includes the resistance element 100m of embodiment 4 are shown, but the invention is not limited thereto. For example, the power amplifier circuits according to embodiments 5, 6, and 7 may include the resistance element 100n according to modification 1 of embodiment 4.

In the circuit diagrams of fig. 15A, 16A, 21A, 22A, and 23A, the field effect transistor is represented by a symbol of an N-channel junction field effect transistor, but the present invention is not limited thereto. For example, the field effect transistors (i.e., the field effect transistors according to embodiments 2, 3, 5, 6, and 7) in these circuit diagrams may be P-channel junction field effect transistors, N-channel MOS (metal oxide semiconductor) field effect transistors, or P-channel MOS field effect transistors. In the MOS field effect transistor, the gate electrode may be made of a metal or a semiconductor.

The above-described embodiments may be variously modified, replaced, added, omitted, and the like within the scope of the claims and the equivalents thereof.

Industrial applicability

The present invention can provide a resistance element exhibiting a stable resistance value with little variation, and can stabilize the characteristics of a circuit. Further, if the structure in which the conductive control layer is provided is employed, a stable variable resistive element can be obtained by applying an arbitrary potential, and a compensation circuit and the like can be manufactured.

Description of the reference symbols

100. 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, 100j, 100k, 100m, 100n resistance elements

101 substrate

102 st nitride semiconductor layer

103 nd nitride semiconductor layer

104 element separation layer

106. 106a, 106g, 106k insulating layer 1

107 two-dimensional electron gas layer

108 surface energy level

109 captured electrons

110 source electrode

111 gate electrode

112 drain electrode

113. 113j 1 st electrode

114. 114j 2 nd electrode

115 st 1 hole injection electrode

116 nd 2 nd hole injection electrode

117 st electron extracting electrode

118 nd 2 nd electron extracting electrode

119 stress buffer layer

Region after 120 ions move

122 mesa structure

123 high resistance layer

124 thin film resistance layer

125 wiring level

126 No. 2 insulating layer

127 th 1 conductive control layer

128 nd 2 conductive control layer

129 field plate electrode

130 No. 3 electrode

131 th electrode

200. 200n field effect transistor

300 low temperature characteristic resistance element part

401. 406, 411, 421, 428 field effect transistors

402. 412, 418, 437 resistors

409. 424, 431 st resistance

410. 427, 433 No. 2 resistor

403. 413 capacitor

404. 404a, 414c, 444 gate terminal

405. 405a, 415c, 445 drain terminals

407. 408, 422, 423, 429, 430 gate bias terminals

416. 425, 432 conductive control layer

417. 434 voltage generating circuit

419. 436 diode

420. 435 bias applying terminal

426 control terminal

500. 500a, 500b, 500c, 500d power amplifier circuit

1000 resistance element part

d1, d2 distance

Direction of movement of M non-reactive ions

Stress of P