阅读说明：本技术 太赫兹元件、半导体装置
(Terahertz element and semiconductor device
) 是由 向井俊和
金在瑛
外山智一郎 于 2018-06-26 设计创作，主要内容包括：本发明的一方案提供的太赫兹元件具备半导体基板、第一导电层、第二导电层、能动元件。上述第一导电层以及第二导电层分别形成于上述半导体基板且相互绝缘。上述能动元件形成于上述半导体基板并与上述第一导电层以及上述第二导电层导通。上述第一导电层包括沿第一方向延伸的第一天线部、在上述半导体基板的厚度方向视角上相对于上述能动元件位于第二方向侧的第一电容部、连接于上述第一电容部的第一导电部。上述第二方向与上述厚度方向和上述第一方向正交。上述第二导电层包括第二电容部。上述第二电容部层叠于上述第一电容部且从上述第一电容部绝缘。上述半导体基板包括从上述第一电容部以及上述第二电容部露出的露出部。上述第一导电部具有在上述厚度方向视角上隔着上述露出部从上述第一天线部向上述第二方向离开的部位。(The terahertz element provided by one aspect of the invention comprises a semiconductor substrate, a first conductive layer, a second conductive layer and an active element. The first conductive layer and the second conductive layer are formed on the semiconductor substrate and insulated from each other. The active element is formed on the semiconductor substrate and is electrically connected to the first conductive layer and the second conductive layer. The first conductive layer includes a first antenna portion extending in a first direction, a first capacitor portion located on a second direction side with respect to the active element in a thickness direction view of the semiconductor substrate, and a first conductive portion connected to the first capacitor portion. The second direction is orthogonal to the thickness direction and the first direction. The second conductive layer includes a second capacitor portion. The second capacitor portion is stacked on the first capacitor portion and insulated from the first capacitor portion. The semiconductor substrate includes an exposed portion exposed from the first capacitor portion and the second capacitor portion. The first conductive portion has a portion separated from the first antenna portion in the second direction through the exposed portion in the thickness direction viewing angle.)
1. A terahertz element is characterized in that,
the disclosed device is provided with:
a semiconductor substrate;
a first conductive layer and a second conductive layer formed on the semiconductor substrate, respectively, and insulated from each other; and
an active element formed on the semiconductor substrate and electrically connected to the first conductive layer and the second conductive layer,
the first conductive layer includes a first antenna portion extending in a first direction, a first capacitor portion located on a second direction side with respect to the active element in a thickness direction view of the semiconductor substrate, and a first conductive portion connected to the first capacitor portion, the second direction being orthogonal to the thickness direction and the first direction,
the second conductive layer includes a second capacitor portion stacked on the first capacitor portion and insulated from the first capacitor portion,
the semiconductor substrate includes an exposed portion exposed from the first capacitor portion and the second capacitor portion,
the first conductive portion has a portion separated from the first antenna portion in the second direction through the exposed portion in the thickness direction viewing angle.
2. The terahertz element of claim 1,
the second conductive layer includes a second antenna portion extending in a third direction opposite to the first direction.
3. The terahertz element of claim 2,
the first conductive layer includes a first inductance part connected to the first antenna part and the first capacitance part and extending from the first antenna part to the first capacitance part along the second direction,
the second conductive layer includes a second inductance part connected to the second antenna part and the second capacitance part and extending from the second antenna part to the second capacitance part along the second direction.
4. The terahertz element according to claim 2 or 3,
the first capacitor portion has a first capacitor portion side surface located on the first direction side in the first capacitor portion,
a side surface of the first capacitor portion is located closer to the third direction than a front end of the first antenna portion on the first direction side,
the second capacitor portion has a first capacitor portion side surface located on the first direction side in the second capacitor portion,
the first capacitor portion side surface of the second capacitor portion is located closer to the third direction side than the tip end of the first antenna portion on the first direction side.
5. The terahertz element of claim 4,
the first capacitor portion has a second capacitor portion side surface located on the third direction side in the first capacitor portion,
the second capacitor portion side surface of the first capacitor portion is located closer to the first direction side than the tip of the second antenna portion on the third direction side,
the second capacitor portion has a second capacitor portion side surface located on the third direction side in the second capacitor portion,
the second capacitor portion side surface of the second capacitor portion is located closer to the first direction side than the tip of the second antenna portion on the third direction side.
6. The terahertz element according to any one of claims 1 to 5,
the first capacitor portion has a size in the first direction different from a size of the second capacitor portion in the first direction.
7. The terahertz element according to any one of claims 1 to 6,
the first conductive part has a first conductive part side surface separated from the first antenna part in the second direction,
the first conductive part side surface extends in the first direction.
8. The terahertz element according to any one of claims 1 to 7,
the first conductive portion has a portion directly connected to the semiconductor substrate.
9. The terahertz element according to any one of claims 1 to 8,
the second conductive layer includes a second conductive portion connected to the second capacitor portion,
the first conductive portion and the second conductive portion are separated from each other in the first direction.
10. The terahertz element of claim 1,
the first conductive part includes a first conductive portion and a first extension portion extending from the first conductive portion,
the first extension part is connected to the first capacitor part,
the second conductive part includes a second conductive portion and a second extending portion extending from the second conductive portion,
the second extending portion is connected to the second capacitor portion.
11. The terahertz element of claim 3,
the second conductive layer includes a second conductive portion disposed on the opposite side of the first conductive portion with the active element interposed therebetween.
12. The terahertz element of claim 11,
the entire first capacitor portion overlaps the first conductive portion in the first direction.
13. The terahertz element according to claim 11 or 12,
the first conductive layer includes a third capacitor portion and a third inductor portion,
the third capacitor portion is located on the opposite side of the first capacitor portion with the first antenna portion interposed therebetween,
the third inductance part is connected to the first antenna part and the third capacitance part and extends from the third capacitance part to the first antenna part along the second direction,
the second conductive layer includes a fourth capacitor portion and a fourth inductor portion,
the fourth capacitor portion is located on the opposite side of the second capacitor portion with the second antenna portion interposed therebetween,
the fourth inductance part is connected to the second antenna part and the fourth capacitance part and extends from the fourth capacitance part to the second antenna part along the second direction.
14. The terahertz element of claim 1,
the semiconductor device further includes an insulating layer interposed between each of the first conductive layer and the second conductive layer and the semiconductor substrate.
15. The terahertz element of claim 14,
a portion of the insulating layer is interposed between the first capacitor portion and the second capacitor portion.
16. A semiconductor device is characterized in that a semiconductor element,
the disclosed device is provided with:
a support body;
the terahertz element according to claim 1, which is disposed on the support; and
an insulating part arranged on the supporting body,
an opening for accommodating the terahertz element is formed in the insulating portion,
the opening has a first side surface inclined with respect to a thickness direction of the support body.
17. The semiconductor device according to claim 16,
the opening has a second side surface surrounding the terahertz element, the second side surface being located between the first side surface and the support body in a thickness direction of the support body,
the second side surface extends in the thickness direction of the support body.
18. The semiconductor device according to claim 17,
the size of the second side surface of the support in the thickness direction is larger than the size of the terahertz element in the thickness direction of the support.
19. The semiconductor device according to claim 17 or 18,
the metal layer is disposed on the first side surface.
20. The semiconductor device according to any one of claims 16 to 19,
the terahertz element further comprises a metal wire bonded to the terahertz element and the support body.
Technical Field
The invention relates to a terahertz element and a semiconductor device.
Background
In recent years, electronic devices such as transistors have been miniaturized, and a new phenomenon called quantum effect has been observed because of their nanometer size. Further, development is being made to achieve ultra-high-speed devices and new functional devices that utilize the quantum effect. In such an environment, tests are also performed for performing large-capacity communication, information processing, imaging, measurement, and the like using a frequency region of 0.1THz to 10THz, which is called a terahertz band. This frequency region is an undeveloped region between light and radio waves, and if a device operating in this frequency band is realized, it is expected to be used in various applications such as measurement in various fields of physics, astronomy, biology, and the like, in addition to the above-described imaging, large-capacity communication, and information processing.
Disclosure of Invention
According to a first aspect of the present invention, a terahertz element is provided. The terahertz element includes a semiconductor substrate, a first conductive layer, a second conductive layer, and an active element. The first conductive layer and the second conductive layer are formed on the semiconductor substrate and insulated from each other. The active element is formed on the semiconductor substrate and is electrically connected to the first conductive layer and the second conductive layer. The first conductive layer includes a first antenna portion extending in a first direction, a first capacitor portion located on a second direction side with respect to the active element in a thickness direction view of the semiconductor substrate, and a first conductive portion connected to the first capacitor portion. The second direction is orthogonal to the thickness direction and the first direction. The second conductive layer includes a second capacitor portion. The second capacitor portion is stacked on the first capacitor portion and insulated from the first capacitor portion. The semiconductor substrate includes an exposed portion exposed from the first capacitor portion and the second capacitor portion. The first conductive portion has a portion separated from the first antenna portion in the second direction with the exposed portion interposed therebetween in the thickness direction viewing angle.
According to a second aspect of the present invention, a semiconductor device is provided. The semiconductor device includes a support, the terahertz element provided by the first aspect and disposed on the support, and an insulating portion disposed on the support. An opening for accommodating the terahertz element is formed in the insulating portion. The opening has a first side. The first side surface is inclined with respect to a thickness direction of the support body.
"something a is formed on something B" and "something a is formed on something B" include "something a is formed directly on something B" and "something a is formed on something B with another object interposed therebetween" unless otherwise specifically prohibited. Similarly, "something a is disposed on something B" and "something a is disposed on something B" include "something a is disposed directly on something B" and "something a is disposed on something B with another object interposed therebetween" unless otherwise specifically prohibited. Similarly, "something a is stacked on something B" and "something a is stacked on something B" include "something a is stacked directly on something B" and "something a is stacked on something B with another object interposed therebetween" unless otherwise specifically prohibited.
Drawings
Fig. 1 is a perspective view of a semiconductor device according to a first embodiment.
Fig. 2 is a plan view of the terahertz element of the first embodiment.
Fig. 3 is a diagram in which the first conductive portion and the first capacitor portion are omitted from fig. 2.
Fig. 4 is a partially enlarged view of a region IV of fig. 2.
Fig. 5 is a detailed cross-sectional view showing the active element of the first embodiment.
Fig. 6 is a partially enlarged view of fig. 5.
Fig. 7 is a sectional view taken along line VII-VII of fig. 2.
Fig. 8 is a sectional view taken along line VIII-VIII of fig. 2.
Fig. 9 is a sectional view taken along line IX-IX of fig. 2.
Fig. 10 is a further sectional view along line IX-IX of fig. 2.
Fig. 11 is a sectional view taken along line XI-XI of fig. 2.
Fig. 12 is a sectional view taken along line XII-XII of fig. 2.
Fig. 13 is another sectional view taken along line XII-XII of fig. 2.
Fig. 14 is a sectional view taken along the line XIV-XIV of fig. 2.
Fig. 15 is a sectional view taken along the line XV-XV of fig. 2.
Fig. 16 is a cross-sectional view of the semiconductor device of fig. 1.
Fig. 17 is a plan view showing a modification of the terahertz element.
Fig. 18 is a top view of the terahertz element of the second embodiment.
Fig. 19 is a top view of the terahertz element of the third embodiment.
Fig. 20 is a top view of the terahertz element of the fourth embodiment.
Fig. 21 is a perspective view of a semiconductor device of an embodiment.
Fig. 22 is a partial sectional view of the semiconductor device of the embodiment.
Fig. 23 is a graph showing antenna gain of terahertz waves with respect to frequencies for a plurality of different values of inner diameter.
Fig. 24 is a graph showing antenna gain of terahertz waves with respect to frequencies for a plurality of different values of size.
Fig. 25 is a graph showing antenna gain of terahertz waves with respect to frequencies for a plurality of different values of size.
Detailed Description
Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
< first embodiment >
A first embodiment of the present invention will be described with reference to fig. 1 to 17. Fig. 1 is a perspective view of a semiconductor device according to a first embodiment.
The semiconductor device a1 shown in the figure is a terahertz oscillation device. The semiconductor device a1 includes a terahertz element B1, a support (including a wiring board 81), an insulating portion 85, and wires 871 and 872.
Fig. 2 is a plan view of the terahertz element of the first embodiment.
The terahertz element B1 shown in the figure is an element that oscillates a high-frequency electromagnetic wave of a terahertz band frequency. The terahertz element B1 includes a semiconductor substrate 1, a first conductive layer 2, a second conductive layer 3, an insulating layer 4 (see fig. 7 and the like), and an active element 5.
The semiconductor substrate 1 is made of a semiconductor and has a semi-insulating property. The semiconductor constituting the semiconductor substrate 1 is, for example, lnP. The semiconductor substrate 1 has a surface 11. The surface 11 faces one direction of the thickness direction Z1 of the semiconductor substrate 1.
The semiconductor substrate 1 includes edges 131 to 134. The edge 131 and the edge 133 are away from each other in the first direction X1. The rim 131 as well as the rim 133 extend in the second direction X2. The second direction X2 is orthogonal to the first direction X1. The rim 132 and the rim 134 are spaced apart from each other in a second direction. The rim 132 and the rim 134 both extend in the first direction X1. Rim 131 is connected to rim 132, rim 132 is connected to rim 133, rim 133 is connected to rim 134, and rim 134 is connected to rim 131.
Fig. 4 is a partially enlarged view of a region IV of fig. 2. As shown in fig. 4, a semiconductor layer 91a is formed on the semiconductor substrate 1. The semiconductor layer 91a is formed of GalnAs, for example.
The active element 5 shown in fig. 2 and 4 is formed on the semiconductor substrate 1. The active element 5 is electrically connected to the first conductive layer 2 and the second conductive layer 3. The active element 5 is formed in the semiconductor layer 91 a. The active element 5 forms a resonator between the second conductive layer 3 and the first conductive layer 2. The electromagnetic wave radiated from the active element 5 is reflected by the back reflector metal layer 88, and has a surface emission radiation pattern in a direction perpendicular to the semiconductor substrate 1 (thickness direction).
As the active element 5, RTD is a representative element. However, the active element 5 may be a diode or a transistor other than an RTD. The active element 5 may be, for example, a Tunnel (Tunnel Transit Time) diode, an avalanche Transit Time (IMPATT) diode, a gallium arsenide Field Effect Transistor (FET), a gallium nitride FET, a High Electron Mobility Transistor (HEMT), or a Heterojunction Bipolar Transistor (HBT).
An example of realizing the active element 5 will be described with reference to fig. 5 and 6. As shown in these figures, the semiconductor layer 91a is disposed on the semiconductor substrate 1. The semiconductor layer 91a is formed of, for example, GalnAs as described above, and is doped with n-type impurities at a high concentration. The GalnAs layer 92a is disposed on the GalnAs layer 91a, and is doped with an n-type impurity. GalnAs93a was disposed in the GalnAs layer 92a, and was not doped with impurities. The AlAs layer 94a is disposed on the GalnAs layer 93a, the lnGaAs layer 95 is disposed on the AlAs layer 94a, and the AlAs layer 94b is disposed on the lnGaAs layer 95. The AlAs layers 94a, the lnGaAs layers 95, and the AlAs layers 94b constitute an RTD portion. The GalnAs layer 93b is disposed on the AlAs layer 94b and is not doped with impurities. The GalnAs layer 92b is disposed on the GalnAs layer 93b, and is doped with an n-type impurity. The GalnAs layer 91b is disposed in the GalnAs layer 92b, and is doped with n-type impurities at a high concentration. The first conductive layer 2 is disposed on the GalnAs layer 91 b. The second conductive layer 3 is disposed on the GalnAs layer 91 a.
Unlike fig. 6, a GalnAs layer doped with an n-type impurity at high concentration may be interposed between the GalnAs layer 91b and the first conductive layer 2. This makes the first conductive layer 2 and the GalnAs layer 91b in contact with each other well.
SiO can also be deposited on the side wall of the laminated structure shown in FIG. 62Film, Si3N4Film, SiON film, HfO2Film, Al2O3Films, etc., or insulating films formed of these multilayer films.
As shown in fig. 2, the first conductive layer 2 and the second conductive layer 3 are formed on the respective semiconductor substrates 1. The first conductive layer 2 and the second guide layer 3 are insulated from each other. The first conductive layer 2 and the second conductive layer 3 each have a metal laminated structure. The laminated structure of first conductive layer 2 and second conductive layer 3 is, for example, a structure in which Au, Pd, and Ti are laminated. Alternatively, the laminated structure of each of first conductive layer 2 and second conductive layer 3 is, for example, a structure in which Au and Ti are laminated. The thickness of each of the first conductive layer 2 and the second conductive layer 3 is, for example, about 20 to 2000 nm. The first conductive layer 2 and the second conductive layer 3 are formed by vacuum evaporation, sputtering, or the like.
The first conductive layer 2 includes a first antenna portion 21, a first inductance portion 22, a first capacitance portion 23, and a first conductive portion 25. The second conductive layer 3 includes a second antenna portion 31, a second inductance portion 32, a second capacitance portion 33, and a second conductive portion 35.
The first antenna part 21 extends in the first direction X1. The first inductance part 22 is connected to the first antenna part 21 and the first capacitance part 23, and extends from the first antenna part 21 to the first capacitance part 23 in the second direction X2. The first inductance section 22 functions as an inductance. The length L1 (see fig. 4) of the first inductor 22 in the second direction X2 is, for example, 5 μm to 100 μm. The width of the first inductance section 22 is, for example, 1 μm to 10 μm. As shown in fig. 4, the first inductance section 22 is separated from the semiconductor layer 91a in a view of the thickness direction Z1.
The second antenna portion 31 extends in the third direction X3. The third direction X3 is a direction opposite to the first direction X1. The second inductance section 32 is connected to the second antenna section 31 and the second capacitance section 33, and extends from the second antenna section 31 to the second capacitance section 33 in the second direction X2. The second inductance section 32 functions as an inductance. The length L2 (see fig. 4) of the second inductor 32 in the second direction X2 is, for example, 5 μm to 100 μm. The width of the second inductance section 32 is, for example, 1 μm to 10 μm.
The length L1 in the second direction X2 of the first inductance part 22 and the length L2 in the second direction X2 of the second inductance part 32 affect the vibration frequency of the terahertz wave. In the present embodiment, the vibration frequency of the terahertz wave is 300 GHz. In order to realize the vibration frequency of 300GHz, the length L1 in the second direction X2 of the first inductance section 22 and the length L2 in the second direction X2 of the second inductance section 32 are 10 μm. As shown in fig. 4, the second inductance section 32 is separated from the semiconductor layer 91a in a view of the thickness direction Z1.
As shown in fig. 2, 4, and the like, the first capacitor 23 is located on the second direction X2 side with respect to the active element 5. In the present embodiment, the first capacitor portion 23 has a rectangular shape in a view of the thickness direction Z1. The first capacitor portion 23 has a first capacitor portion side 231 and a second capacitor portion side 232. The first capacitor portion side 231 is located on the first direction X1 side in the first capacitor portion 23. The first capacitor portion side 231 is located on the third direction X3 side opposite to the first direction X1 with respect to the front end 211 of the first antenna portion 21 on the first direction X1 side. The second capacitor portion side 232 is located on the third direction X3 side in the first capacitor portion 23. The second capacitance section side 232 extends in the second direction X2. The second capacitor portion side 232 is located on the first direction X1 side with respect to the front end 311 of the second antenna portion 31 on the third direction X3 side.
Fig. 3 is a diagram in which the first conductive portion 25 and the first capacitive portion 23 are omitted from fig. 2.
The second capacitor 33 is located on the second direction X2 side with respect to the active element 5. As shown in fig. 15, the first capacitor portion 23 is interposed between the second capacitor portion 33 and the semiconductor substrate 1. Unlike the present embodiment, the second capacitor 33 may be interposed between the first capacitor 23 and the semiconductor substrate 1. The second capacitor portion 33 is laminated on the first capacitor portion 23 and insulated from the first capacitor portion 23 by the insulating layer 4. The second capacitor 33 and the first capacitor 23 constitute a capacitor. In the present embodiment, the second capacitance section 33 is rectangular in shape in a view of the thickness direction Z1. In the present embodiment, as shown in fig. 15, a dimension W2 in the first direction X1 of the second capacitor section 33 is different from a dimension W1 in the first direction X1 of the first capacitor section 23. In the present embodiment, dimension W2 in the first direction X1 of the second capacitor unit 33 is larger than dimension W1 in the first direction X1 of the first capacitor unit 23. Thus, even if the formation position of the second capacitor portion 33 is shifted due to manufacturing errors, the second capacitor portion 33 can be more reliably formed on the first capacitor portion 23. Unlike the present embodiment, the dimension W2 in the first direction X1 of the second capacitor portion 33 may be smaller than the dimension W1 in the first direction X1 of the first capacitor portion 23.
As shown in fig. 3, the second capacitor 33 has a first capacitor side 331 and a second capacitor side 332. The first capacitor portion side surface 331 is located on the first direction X1 side on the second capacitor portion 33. The first capacitor portion side 331 extends in the second direction X2. The first capacitor portion side 331 is located on the third direction X3 side opposite to the first direction X1 with respect to the front end 211 of the first antenna portion 21 on the first direction X1 side. The second capacitor portion side surface 332 is located on the third direction X3 side on the second capacitor portion 33. The second capacitor portion side surface 332 extends in the second direction X2. The second capacitor portion side surface 332 is located on the first direction X1 side with respect to the front end 311 of the second antenna portion 31 on the third direction X3 side.
As shown in fig. 2, the semiconductor substrate 1 includes an exposed portion 12A and an exposed portion 12B. The exposed portions 12A and 12B are exposed from the first capacitor portion 23 and the second capacitor portion 33, respectively. The exposed portion 12A is located on the first direction X1 side with respect to the first capacitor portion 23 and the second capacitor portion 33. The exposed portion 12B is located on the third direction X3 side with respect to the first capacitor portion 23 and the second capacitor portion 33.
The first conductive portion 25 is connected to the first capacitor portion 23. In the present embodiment, the first conductive part 25 has a rectangular shape. In the present embodiment, the first conductive portion 25 is a pad portion to which the wire 871 (see fig. 1) is connected. As shown in fig. 11, the first conductive portion 25 has a portion directly connected to the semiconductor substrate 1. The connecting portion overlaps the wire connecting portion where the wire 871 is connected to the first conductive portion 25 in the view of the thickness direction Z1. As shown in fig. 2, the first conductive portion 25 has a portion 259 separated from the first antenna portion 21 in the second direction X2 through the exposed portion 12A when viewed in the thickness direction Z1. The first conductive portion includes a first conductive portion side surface 251. The first conductive part side surface 251 is separated from the first antenna part 21 in the second direction X2 through the exposed part 12A in the view of the thickness direction Z1. In the present embodiment, the first conductive part side surface 251 has a shape extending in the first direction X1. Unlike the present embodiment, the first conductive part side surface 251 may have a curved shape.
In the present embodiment, as shown in fig. 2, the first conductive portion 25 reaches the edge 131 and the edge 132 in the view of the thickness direction Z1. As shown in fig. 17, the first conductive portion 25 may not reach the edge 131 and the edge 132 in the thickness direction Z1. In this case, in the manufacturing process of the terahertz element B1, the burr generated in the first conductive portion 25 can be suppressed from being cut off when the semiconductor substrate 1 is diced.
The second conductive portion 35 is connected to the second capacitive portion 33. In the present embodiment, the second conductive portion 35 has a rectangular shape. In the present embodiment, the second conductive portion 35 is a pad portion to which the wire 872 is connected. As shown in fig. 12, the second conductive portion 35 has a portion directly connected to the semiconductor substrate 1. The connecting portion overlaps the wire connecting portion where the wire 872 and the second conductive portion 35 are connected, in the view of the thickness direction Z1. As shown in fig. 2, the second conductive portion 35 has a portion 359 spaced apart from the second antenna portion 31 in the second direction X2 through the exposed portion 12B in a view of the thickness direction Z1. The second conductive portion 35 includes a second conductive portion side surface 351. The second conductive part side surface 351 is separated from the second antenna part 31 in the second direction X2 with the exposed part 12B interposed therebetween in the thickness direction Z1. In the present embodiment, the second conductive portion side surface 351 has a shape extending in the first direction X1. Unlike the present embodiment, the second conductive part side surface 351 may have a curved shape.
In the present embodiment, as shown in fig. 2, the second conductive portions 35 reach the edges 133 and 132 in the view of the thickness direction Z1. As shown in fig. 17, the second conductive portion 35 may not reach the edge 133 and the edge 132 in the thickness direction Z1. In this case, in the manufacturing process of the terahertz element B1, the burr generated in the second conductive portion 35 can be suppressed from being cut off when the semiconductor substrate 1 is diced.
The insulating layer 4 shown in FIGS. 8 to 15 is made of, for example, SiO2And (4) forming. Alternatively, the material constituting the insulating layer 4 may be Si3N4、SiON、HfO2Or Al2O3. The thickness of the insulating layer 4 is, for example, about 10nm to 1000 nm. The insulating layer 4 is formed by, for example, a CVD method or a sputtering method. The insulating layer 4 is interposed between the first conductive layer 2 (e.g., the first antenna portion 21, the first inductance portion 22, and the first conductive portion 25) and the semiconductor substrate 1, and between the second conductive layer 3 (the second antenna portion 31, the second inductance portion 32, and the second conductive portion 35) and the semiconductor substrate 1. As described above, a part of the insulating layer 4 is interposed between the first capacitor portion 23 and the second capacitor portion 33 (see fig. 15).
Fig. 16 is a cross-sectional view of the semiconductor device a1 of fig. 1.
The wiring board 81 shown in fig. 16 is, for example, an epoxy glass substrate. The terahertz element B1 is disposed on the wiring board 81. The wiring pattern 82 is formed on the wiring substrate 81. The wiring pattern 82 includes a first portion 821 and a second portion 822. The first portion 821 and the second portion 822 are separated from each other.
The insulating portion 85 is disposed on the wiring board 81. The insulating portion 85 is made of, for example, resin (e.g., epoxy resin). The insulation 85 has a surface 853. The surface 853 faces one direction of the thickness direction of the wiring board 81 (in the present embodiment, coincides with the thickness direction Z1 of the semiconductor substrate 1). An opening 851 for housing the terahertz element B1 is formed in the insulating portion 85. The opening 851 has a first side 851A and a second side 851B. The first side surface 851A is inclined with respect to the thickness direction Z1 of the wiring board 81. The second side surface 851B is located between the first side surface 851A and the wiring board 81 in the thickness direction Z1 of the wiring board 81. The second side surface 851B extends in the thickness direction Z1 of the wiring board 81. The size of the second side surface 851B in the thickness direction Z1 of the wiring substrate 81 is larger than the size of the terahertz element B1 in the thickness direction Z1 of the wiring substrate 81.
As shown in fig. 16, a metal layer 86 may be disposed on the first side 851A. As shown in this figure, the metal layer 86 may be disposed on the second side 851B. Metal layer 86 may be a metallization layer. The metal layer 86 reflects the terahertz waves more efficiently. The wires 871 and 872 are joined to the terahertz element B1 and the wiring board 81 (more precisely, the wiring pattern 82). The wire 871 is joined to the first conductive portion 25 of the terahertz element B1 and the first portion 821 of the wiring pattern 82. The wire 872 is bonded to the second conductive portion 35 of the terahertz element B1 and the second portion 822 of the wiring pattern 82. The first side 851A and the second side 851B may be made of metal.
In the present embodiment, as shown in fig. 2, the semiconductor substrate 1 includes an exposed portion 12A exposed from the first capacitor portion 23 and the second capacitor portion 33. The first conductive portion 25 has a portion 259 separated from the first antenna portion 21 in the second direction X2 through the exposed portion 12A in a view of the thickness direction Z1. With such a structure, the area of the first conductive layer 2 close to the active element 5 can be further reduced. This can reduce the possibility that the first conductive layer 2 (particularly the first conductive portion 25) exerts an adverse effect on the polarization characteristics of the terahertz wave emitted from the active element 5.
In the present embodiment, as shown in fig. 11, the first conductive portion 25 has a portion directly connected to the semiconductor substrate 1. With such a configuration, the wire can be bonded to a harder position in the first conductive portion 25. This can prevent the wire from coming off the first conductive portion 25. The same advantages apply with respect to the second conductive portion 35 shown in fig. 12.
In the present embodiment, as shown in fig. 16, the opening 851 of the insulating portion 85 has a first side surface 851A. The first side surface 851A is inclined with respect to the thickness direction Z1 of the wiring board 81. According to such a structure, even if the terahertz wave emitted from the terahertz element B1 is reflected by the detection device of the terahertz wave, for example, the terahertz wave can be prevented from being reflected by the first side surface 851A and directed toward the detection device as much as possible. This can reduce the interference effect due to the reflection of the terahertz wave. At the same time, the antenna efficiency can also be improved.
In the present embodiment, as shown in fig. 16, the second side surface 851B extends in the thickness direction Z1 of the wiring board 81. With such a structure, the terahertz wave can be reflected multiple times on the second side surface 851B, and can be directed in the thickness direction Z1. This enables the terahertz wave to be directed more efficiently upward in fig. 16.
In the present embodiment, the size of the second side surface 851B in the thickness direction Z1 of the wiring substrate 81 is larger than the size of the terahertz element B1 in the thickness direction Z1 of the wiring substrate 81. With such a structure, the terahertz wave can be directed more efficiently upward in fig. 16.
< second embodiment >
A second embodiment of the present invention will be described with reference to fig. 18.
In the following description, the same or similar components as those described above are denoted by the same reference numerals as those described above, and the description thereof will be omitted as appropriate.
In the terahertz element B2 shown in fig. 18, the first conductive part 25 includes a first conductive portion 253 and a first extension portion 254 extending from the first conductive portion 253. The first extension portion 254 is connected to the first capacitor portion 23. The second conductive portion 35 includes a second conductive portion 353 and a second extension portion 354 extending from the second conductive portion 353. The second extension portion 354 is connected to the second capacitor portion 33. Other aspects of the terahertz element B2 are substantially the same as those described in the terahertz element B1, and therefore, description thereof is omitted. The present embodiment can also enjoy the same advantages as those described in the first embodiment.
< third embodiment >
A third embodiment of the present invention will be described with reference to fig. 19.
The first conductive layer 2 and the second conductive layer 3 of the terahertz element B3 shown in fig. 19 are different in shape from those of the terahertz element B1. In the terahertz element B3, the first conductive layer 2 and the second conductive layer 3 include the second conductive portion 35 disposed on the opposite side of the first conductive portion 25 with the active element 5 interposed therebetween.
The first conductive layer 2 includes a third inductance part 236 and a third capacitance part 237 in addition to the first antenna part 21, the first inductance part 22, the first capacitance part 23, and the first conductive part 25. Second conductive layer 3 includes fourth inductance part 336 and fourth capacitance part 337 in addition to second antenna part 31, second inductance part 32, second capacitance part 33, and second conductive part 35.
The first antenna part 21 extends in the first direction X1. The first inductance part 22 is connected to the first antenna part 21 and the first capacitance part 23 and extends from the first antenna part 21 to the first capacitance part 23 along the second direction X2. The third inductance part 236 is connected to the first antenna part 21 and the third capacitance part 237 and extends from the third capacitance part 237 to the first antenna part 21 along the second direction X2. The first inductance part 22 and the third inductance part 236 function as inductors.
The lengths of the first inductor 22 and the third inductor 236 in the second direction X2 are, for example, 10 μm to 200 μm. The widths of the first inductor 22 and the third inductor 236 are, for example, 1 μm to 10 μm. In the case where the same vibration frequency as that of the terahertz element B1 of the first embodiment is obtained, the lengths of the first inductance section 22 and the third inductance section 236 in the second direction X2 of the present embodiment may be multiples of the length of the first inductance section 22 of the first embodiment in the second direction X2.
The second antenna portion 31 extends in the third direction X3. The second inductance section 32 is connected to the second antenna section 31 and the second capacitance section 33 and extends from the second antenna section 31 to the second capacitance section 33 in the second direction X2. The fourth inductance portion 336 is connected to the second antenna portion 31 and the fourth capacitance portion 337 and extends from the fourth capacitance portion 337 to the second antenna portion 31 along the second direction X2. The second inductance part 32 and the fourth inductance part 336 function as inductances.
The lengths of the second inductance part 32 and the fourth inductance part 336 in the second direction X2 are, for example, 10 μm to 200 μm. The widths of the second inductor 32 and the fourth inductor 336 are, for example, 1 μm to 10 μm. In the case where the same vibration frequency as that of the terahertz element B1 of the first embodiment is obtained, the lengths of the second inductance section 32 and the fourth inductance section 336 of the present embodiment in the second direction X2 may be multiples of the length of the second inductance section 32 of the first embodiment in the second direction X2.
The first capacitor 23 and the second capacitor 33 are applicable to the description of the first embodiment, and therefore the description thereof is omitted in this embodiment.
The semiconductor substrate 1 includes an exposed portion 12A, an exposed portion 12B, an exposed portion 12C, and an exposed portion 12D. Since the exposed portions 12A and 12B are as described in the first embodiment, the description thereof is omitted in this embodiment. The exposed portion 12C and the exposed portion 12D are exposed from the third capacitor portion 237 and the fourth capacitor portion 337, respectively. The exposed portion 12C is located on the first direction X1 side with respect to the third capacitor portion 237 and the fourth capacitor portion 337. The exposed portion 12D is located on the third direction X3 side with respect to the third capacitor portion 237 and the fourth capacitor portion 337.
The first conductive portion 25 is connected to the first capacitor portion 23. The entire first capacitor portion 23 overlaps the first conductive portion 25 in the first direction X1. In the present embodiment, the first conductive part 25 has a rectangular shape. In the present embodiment, the first conductive portion 25 is a conductive portion of the bonding wire. The first conductive portion 25 has a portion 259A separated from the first antenna portion 21 in the second direction X2 through the exposed portion 12A in a view in the thickness direction Z1. The first conductive portion 25 has a portion 259B separated from the second antenna portion 31 in the second direction X2 through the exposed portion 12B when viewed in the thickness direction Z1.
The second conductive portion 35 is connected to the fourth capacitive portion 337. The entire fourth capacitive portion 337 overlaps the second conductive portion 35 in the first direction X1. In the present embodiment, the second conductive portion 35 has a rectangular shape. In the present embodiment, the second conductive portion 35 is a conductive portion to which a wire is bonded. The second missile portion 35 has a portion 359A separated from the first antenna portion 21 in the fourth direction X4 opposite to the second direction X2 in the thickness direction Z viewing angle through the exposed portion 12C. The second conductive portion 35 has a portion 359B separated from the second antenna portion 31 in the fourth direction X4 through the exposed portion 12B in a view angle in the thickness direction Z1.
Even with such a structure, the same advantages as those described in the first embodiment can be enjoyed.
< fourth embodiment >
A fourth embodiment of the present invention will be described with reference to fig. 20.
In the terahertz element B4 shown in the figure, the first conductive layer 2 has a portion 29, and the second conductive layer 3 has a portion 39. In the present embodiment, the portions 29 and 39 may be mutually insulated and laminated. Even with such a structure, the same advantages as those described in the first embodiment can be enjoyed.
< example >
An example of the first embodiment of the present invention will be described with reference to fig. 21 to 25. Here, although the example of the first embodiment is described, the example is also applied to embodiments (second, third, and fourth embodiments) other than the first embodiment.
As shown in fig. 21 and 22, one side of the semiconductor device a1 in the plan view is defined as a dimension L11, the other side thereof is defined as a dimension L12, and the inner diameter of the opening 851 is defined as an inner diameter D1. As shown in fig. 22, the dimension in the direction Z1 of the first side 851A of the opening 851 is set to a dimension L22, and the dimension in the direction Z1 of the second side 851B of the opening 851 is set to a dimension L21. Fig. 21 and 22 are additional drawings and inner diameter drawings of fig. 1 and 16, respectively.
Fig. 23 shows antenna Gain (Gain) of terahertz waves from the semiconductor device a1 with respect to frequencies with respect to values of the inner diameters D1 that are different from each other. Fig. 23 shows the calculation results for the inner diameters D1 of 1.8mm, 2.0mm, and 2.2 mm. The dimensions L11 and L12 were 3.4mm, respectively, the dimension L21 was 0.9mm, and the dimension L22 was 1.0 mm. The first side 851 of the opening 851 is inclined 20 degrees with respect to the direction Z1. The antenna gain of the semiconductor device a1 is preferably 7dB or more and 8dB or more, for example. In the example shown in fig. 23, it is shown that even if the inner diameter D1 is any one of 1.8mm, 2.0mm, and 2.2mm, the semiconductor device a1 has an antenna gain of 7dB or more, for example. For example, the preferred results are shown in the range of 300 to 330GHz in frequency of the terahertz element. However, the frequency of the terahertz element may use a value outside this range. According to FIG. 23, for example, considering the result of the case where the inner diameter D1 is 1.8mm, the inner diameter D1 can be 1.7 to 1.9mm, for example. As shown in FIG. 23, considering the result of the case where the inner diameter D1 is 2.0mm, the inner diameter D1 can be set to 1.9 to 2.1mm, for example. According to FIG. 23, for example, considering the result of the case where the inner diameter D1 is 2.2mm, the inner diameter D1 can be, for example, 2.1 to 2.3 mm. The inner diameter D1 may be 1.7 to 2.3 mm.
Fig. 24 shows antenna Gain (Gain) of a terahertz wave from the semiconductor device a1 with respect to a frequency with respect to a value of the dimension L21 different from each other. Fig. 24 shows the calculation results when the inner diameter L21 was 0.3mm, 0.6mm, and 0.9 mm. In the example shown in fig. 24, the characteristics of the semiconductor device a1 can be improved by making the dimension L21 large. The dimensions L11 and L12 were 3.4mm, the inner diameter D1 was 2.2mm, and the dimension L22 was 1.0mm, respectively. The first side 851 of the opening 851 is inclined 20 degrees with respect to the direction Z1. The antenna gain of the semiconductor device a1 is preferably 7dB or more and 8dB or more, for example. In the example shown in fig. 24, it is shown that even if the dimension L21 is any one of the values of 0.3mm, 0.6mm, and 0.9mm, the semiconductor device a1 has an antenna gain of 7dB or more, for example. For example, the preferred results are shown in the range of 300 to 330GHz in frequency of the terahertz element. However, the frequency of the terahertz element may use a value outside this range. According to fig. 24, for example, considering the case where the dimension L21 is 0.3mm, the dimension L21 can be 0.2 to 0.4mm, for example. From fig. 24, considering the result of the dimension L21 being 0.6mm, the dimension L21 can be 0.5 to 0.7mm, for example. According to fig. 24, for example, considering the case where the dimension L21 is 0.9mm, the dimension L21 can be 0.8 to 1.0mm, for example. Further, the dimension L21 may be 0.2 to 1.0 mm.
Fig. 25 shows antenna Gain (Gain) of a terahertz wave from the semiconductor device a1 with respect to a frequency with respect to a value of the dimension L22 different from each other. Fig. 25 shows the calculation results for the dimensions L22 of 0.7mm, 1.0mm, and 1.3 mm. In the example shown in fig. 25, the characteristics of the semiconductor device a1 can be improved by making the dimension L22 large. The dimensions L11 and L12 were 3.4mm, respectively, the inner diameter D1 was 2.2mm, and the dimension L21 was 0.9 mm. The first side 851 of the opening 851 is inclined 20 degrees with respect to the direction Z1. The antenna gain of the semiconductor device a1 is preferably 7dB or more and 8dB or more, for example. In the example shown in fig. 25, it is shown that even if the dimension L22 is any one of the values of 0.7mm, 1.0mm, and 1.3mm, the semiconductor device a1 has an antenna gain of 7dB or more, for example. For example, the preferred results are shown in the range of 300 to 330GHz in frequency of the terahertz element. However, the frequency of the terahertz element may use a value outside this range. According to fig. 25, for example, considering the case where the dimension L22 is 0.7mm, the dimension L22 can be 0.6 to 0.8mm, for example. According to fig. 25, considering the result that the dimension L22 is 1.0mm, the dimension L22 can be 0.9 to 1.1mm, for example. According to fig. 25, for example, considering the case where the dimension L22 is 1.3mm, the dimension L22 can be, for example, 1.2 to 1.4 mm. Further, the dimension L22 may be 0.6 to 1.4 mm.
The present invention is not limited to the above-described embodiments. The specific structure of each part of the present invention can be variously changed in design.
The above embodiments include the following remarks.
[ Note 1]
A terahertz element is characterized in that,
the disclosed device is provided with:
a semiconductor substrate;
a first conductive layer and a second conductive layer formed on the semiconductor substrate, respectively, and insulated from each other; and
an active element formed on the semiconductor substrate and electrically connected to the first conductive layer and the second conductive layer,
the first conductive layer includes a first antenna portion extending in a first direction, a first capacitor portion located on a second direction side with respect to the active element in a thickness direction view of the semiconductor, and a first conductive portion connected to the first capacitor portion, the second direction being orthogonal to the thickness direction and the first direction,
the second conductive layer includes a second capacitor portion stacked on the first capacitor portion and insulated from the first capacitor portion,
the semiconductor substrate includes an exposed portion exposed from the first capacitor portion and the second capacitor portion,
the first conductive portion has a portion separated from the first antenna portion in the second direction through the exposed portion in the thickness direction viewing angle.
[ pay note 2]
The terahertz element according to note 1, wherein,
the second conductive layer includes a second antenna portion extending in a third direction opposite to the first direction.
[ pay 3]
The terahertz element according to note 2, wherein,
the first conductive layer includes a first inductance part connected to the first antenna part and the first capacitance part and extending from the first antenna part to the first capacitance part along the second direction,
the second conductive layer includes a second inductance part connected to the second antenna part and the second capacitance part and extending from the second antenna part to the second capacitance part along the second direction.
[ pay 4]
The terahertz element according to note 2 or 3, wherein,
the first capacitor portion has a first capacitor portion side surface located on the first direction side in the first capacitor portion,
a side surface of the first capacitor portion is located closer to the third direction than a front end of the first antenna portion on the first direction side,
the second capacitor portion has a first capacitor portion side surface located on the first direction side in the second capacitor portion,
the first capacitor portion side surface of the second capacitor portion is located closer to the third direction side than the tip end of the first antenna portion on the first direction side.
[ pay 5]
The terahertz element according to note 4 above, wherein,
the first capacitor portion has a second capacitor portion side surface located on the third direction side in the first capacitor portion,
the second capacitor portion side surface of the first capacitor portion is located closer to the first direction side than the tip of the second antenna portion on the third direction side,
the second capacitor portion has a second capacitor portion side surface located on the third direction side in the second capacitor portion,
the second capacitor portion side surface of the second capacitor portion is located closer to the first direction side than the tip of the second antenna portion on the third direction side.
[ pay 6]
The terahertz element according to any one of notes 1 to 5, wherein,
a dimension of the first capacitor portion in the first direction is different from a dimension of the second capacitor portion in the second direction.
[ pay 7]
The terahertz element according to any one of notes 1 to 6, wherein,
the first conductive part has a first conductive part side surface separated from the first antenna part in the second direction,
the first conductive part side surface extends in the first direction.
[ pay 8]
The terahertz element according to any one of notes 1 to 7, wherein,
the first conductive portion has a portion directly connected to the semiconductor substrate.
[ pay 9]
The terahertz element according to any one of notes 1 to 8, wherein,
the second conductive layer includes a second conductive portion connected to the second capacitor portion,
the first conductive portion and the second conductive portion are separated from each other in the first direction.
[ pay 10]
The terahertz element according to note 1, wherein,
the first conductive part includes a first conductive portion and a first extension portion extending from the first conductive portion,
the first extension part is connected to the first capacitor part,
the second conductive part includes a second conductive portion and a second extending portion extending from the second conductive portion,
the second extending portion is connected to the second capacitor portion.
[ pay 11]
The terahertz element according to note 3, wherein,
the second conductive layer includes a second conductive portion disposed on the opposite side of the first conductive portion with the active element interposed therebetween.
[ pay note 12]
The terahertz element according to note 11, wherein,
the entire first capacitor portion overlaps the first conductive portion in the first direction.
[ pay note 13]
The terahertz element according to claim 11 or 12, characterized in that,
the first conductive layer includes a third capacitor portion and a third inductor portion,
the third capacitor portion is located on the opposite side of the first capacitor portion with the first antenna portion interposed therebetween,
the third inductance part is connected to the first antenna part and the third capacitance part and extends from the third capacitance part to the first antenna part along the second direction,
the second conductive layer includes a fourth capacitor portion and a fourth inductor portion,
the fourth capacitor portion is located on the opposite side of the second capacitor portion with the second antenna portion interposed therebetween,
the fourth inductance part is connected to the second antenna part and the fourth capacitance part and extends from the fourth capacitance part to the second antenna part along the second direction.
[ pay note 14]
The terahertz element according to note 1, wherein,
the semiconductor device further includes an insulating layer interposed between each of the first conductive layer and the second conductive layer and the semiconductor substrate.
[ pay note 15]
The terahertz element according to claim 14, wherein,
a portion of the insulating layer is interposed between the first capacitor portion and the second capacitor portion.
[ pay note 16]
A semiconductor device is characterized in that a semiconductor element,
the disclosed device is provided with:
a support body;
the terahertz element described in supplementary note 1 disposed on the support; and
an insulating part arranged on the supporting body,
an opening for accommodating the terahertz element is formed in the insulating portion,
the opening has a first side surface inclined with respect to a thickness direction of the support body.
[ Note 17]
The semiconductor device according to claim 16, wherein the first and second semiconductor layers are formed of a semiconductor material,
the opening has a second side surface surrounding the terahertz element, the second side surface being located between the first side surface and the support body in a thickness direction of the support body,
the second side surface extends in the thickness direction of the support body.
[ pay 18]
The semiconductor device according to claim 17, wherein the semiconductor device further comprises a second semiconductor layer,
the size of the second side surface in the thickness direction of the support body is larger than the size of the terahertz element in the thickness direction of the support body.
[ pay 19]
The semiconductor device according to claim 17 or 18, wherein the semiconductor device further comprises a second semiconductor element,
the metal layer is disposed on the first side surface.
[ pay 20]
The semiconductor device according to any one of claims 16 to 19, wherein the semiconductor device is further provided with a second semiconductor element,
the terahertz element further comprises a metal wire bonded to the terahertz element and the support body.
