阅读说明：本技术 一种基于氮化镓的宽摆幅双向限幅电路及其制备方法 (Wide-swing bidirectional amplitude limiting circuit based on gallium nitride and preparation method thereof ) 是由 杨凌 马晓华 芦浩 宓珉翰 侯斌 周小伟 祝杰杰 郝跃 于 2018-07-23 设计创作，主要内容包括：本发明涉及一种基于氮化镓的宽摆幅双向限幅电路的制备方法,包括制作PIN二极管、肖特基二极管以及GaN基器件,并将PIN二极管和肖特基二极管并联后通过金属互联工艺与GaN基器件连接,从而完成基于氮化镓的宽摆幅双向限幅电路的制备。本发明实施例,通过采用将PIN二极管和肖特基二极管并联再与GaN基器件的栅极连接的电路,可以实现电路的自我保护,同时满足器件能够承受正反向大功率信号的冲击,实现器件的双向保护。(The invention relates to a preparation method of a wide-swing bidirectional amplitude limiting circuit based on gallium nitride, which comprises the steps of manufacturing a PIN diode, a Schottky diode and a GaN-based device, connecting the PIN diode and the Schottky diode in parallel and then connecting the PIN diode and the Schottky diode with the GaN-based device through a metal interconnection process, and thus completing the preparation of the wide-swing bidirectional amplitude limiting circuit based on the gallium nitride. According to the embodiment of the invention, the PIN diode and the Schottky diode are connected in parallel and then connected with the grid electrode of the GaN-based device, so that the self-protection of the circuit can be realized, the impact of forward and reverse high-power signals on the device can be borne, and the bidirectional protection of the device can be realized.)

1. A preparation method of a wide-swing bidirectional amplitude limiting circuit based on gallium nitride is characterized by being applied to an AlGaN/GaN heterojunction, wherein the AlGaN/GaN heterojunction comprises a substrate layer, a nucleation layer, a GaN layer, a first AlGaN barrier layer and a second AlGaN barrier layer, and the method comprises the following steps:

s1, photoetching the first AlGaN barrier layer, and etching to remove the first AlGaN barrier layer;

s2, forming a PIN diode manufacturing region and a Schottky diode manufacturing region on the GaN layer;

s3, manufacturing the PIN diode in the PIN diode manufacturing area;

s4, manufacturing the Schottky diode in the Schottky diode manufacturing area;

s5, manufacturing a GaN-based device on the second AlGaN barrier layer;

and S6, connecting the PIN diode and the Schottky diode in parallel and then connecting the PIN diode and the Schottky diode with the GaN-based device through metal interconnection to obtain the wide-swing bidirectional amplitude limiting circuit based on the gallium nitride.

2. The method according to claim 1, wherein S3 comprises:

s31, growing a doped N + layer on the GaN layer, growing an I layer on the N + layer, and growing a doped P + layer on the I layer;

s32, photoetching the P + layer, and evaporating metal to form a P + layer electrode;

s33, photoetching the P + layer to form a groove digging region, and etching the P + layer to the surface of the N + layer;

and S34, photoetching the N + layer, and evaporating metal to form an N + layer electrode to obtain the PIN diode.

3. The method according to claim 2, wherein S4 comprises:

s41, epitaxially growing a doped N + type GaN layer on the GaN layer;

s42, epitaxially growing a doped N-type GaN layer on the N + type GaN layer;

s43, photoetching the N-type GaN layer and evaporating the metal stack layer to form Schottky contact, and finishing the manufacture of the N-type GaN layer electrode;

s44, etching the N + type GaN layer and the N-type GaN layer to form an etching area;

and S45, photoetching the etching area and evaporating ohmic metal to form ohmic contact, and finishing the manufacture of the N + type GaN layer electrode to obtain the Schottky diode.

4. The method according to claim 1, wherein S5 comprises:

s51, evaporating ohmic metal on the second AlGaN barrier layer to form a source electrode and a drain electrode respectively;

s52, growing an SiN medium layer on the source electrode, the drain electrode and the second AlGaN barrier layer;

s53, manufacturing a mask on the SiN medium layer, and etching a groove;

and S54, photoetching a T-shaped gate region on the groove, and evaporating metal in the T-shaped gate region to form a gate to obtain the GaN-based device.

5. The method according to claim 3, wherein S6 comprises:

s61, depositing a first SiN protective layer on the surfaces of the P + layer electrode and the N + layer electrode;

s62, depositing a second SiN protective layer on the surfaces of the N-type GaN layer electrode and the N + type GaN layer electrode;

s63, depositing SiO on the source electrode, the drain electrode and the grid electrode₂A protective layer;

s64, photoetching the first SiN protective layer, the second SiN protective layer and the SiO₂Forming a metal interconnection layer open hole region on the protective layer, and etching the first SiN protective layer, the second SiN protective layer and the SiO of the metal interconnection layer open hole region₂A protective layer;

s65, a first SiN protective layer, a second SiN protective layer and SiO in the metal interconnection layer open hole region₂The protective layer is evaporated with interconnection metal to connect the PIN diode and the Schottky diode in parallelAnd then the GaN-based device is connected to form the wide-swing bidirectional amplitude limiting circuit based on the gallium nitride.

6. The method according to claim 2, wherein the doped N + layer has a thickness of 10 μm and a doping concentration of 1 × 10¹⁶cm^-3～1×10¹⁸cm^-3The doping element is Si; the thickness of the layer I is 20-70 mu m; the thickness of the doped P + layer is 1-10 μm, and the doping concentration is 1 × 10¹⁹cm^-3～1×10²⁰cm^-3The doping element is Mg.

7. The method according to claim 3, wherein the doped N + GaN layer has a thickness of 10 μm to 40 μm and a doping concentration of 10¹⁸～10¹⁹cm^-3(ii) a The thickness of the doped N-type GaN layer is 20-90 μm, and the doping concentration is 10¹⁴～10¹⁷cm^-3(ii) a The Schottky contact area is 1 multiplied by 10^-4cm²～4×10^-4cm²。

8. The method according to claim 4, wherein the thickness of the SiN dielectric layer is 60nm to 120nm, and the gate length is 0.2 μm to 0.5 μm.

9. The method according to claim 5, wherein the first SiN protection layer is 150-200 nm thick, and the second SiN protection layer is 150-200 nm thick.

10. A wide swing bidirectional limiting circuit based on gan, produced by the method of any of claims 1-9.

Technical Field

The invention belongs to the technical field of semiconductor devices, and particularly relates to a wide-swing bidirectional amplitude limiting circuit based on gallium nitride and a preparation method thereof.

Background

With the continuous progress of semiconductor technology, silicon-based semiconductor technology has been continuously developed for decades and has become the most mature technology in the current semiconductor technology, but in the field of power semiconductors, silicon-based devices are approaching the theoretical limit, first and second-generation semiconductor materials have been unable to meet the requirements of higher-frequency and higher-power electronic devices, and the research on novel semiconductor material devices is particularly important, electronic devices based on nitride semiconductor materials can meet the requirements, and GaN materials have the advantages of larger forbidden bandwidth, higher critical breakdown electric field, higher electron mobility, higher electron saturation speed, capability of working under higher temperature conditions and the like compared with silicon materials, and have great exploration potential.

The front end of a radar receiver often has a high-sensitivity low-noise amplifier, and the low-noise amplifier is a small-signal linear device, which receives very weak signals, but the whole system must be capable of bearing larger power. In order to protect the devices from being burned, a microwave limiter is usually added to the front end of the receiver. When a small signal is input, the amplitude limiter only presents small loss, and when a large signal is input, the amplitude limiter greatly attenuates the small signal.

The PIN diode is a semiconductor diode which is formed by a three-layer structure, namely a P layer formed by heavily doping a P type material, an N layer formed by heavily doping an N type material, and an I layer formed by a high-resistivity lightly doped intrinsic layer sandwiched between the P layer and the N layer.

At present, GaAs MESFET amplitude limiters, GaAs Schottky barrier amplitude limiters and the like are mainly adopted at home and abroad, and the device is required to have low on-state resistance and low off-state capacitance, can bear the impact of high-power signals, and has the characteristics of small area, superior performance and the like compared with a GaAs MESFET amplitude limiter single-chip circuit.

However, the gallium arsenide second-generation semiconductor material cannot meet the requirements of electronic devices with higher frequency and higher power, and the schottky barrier limiter has insufficient capability of bearing the impact of high-power signals in the same area, so that the defect is obvious.

Therefore, how to meet the requirement that the device can bear the impact of forward and reverse high-power signals is important, and the circuit can be protected.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a wide-swing bidirectional amplitude limiting circuit based on gallium nitride and a preparation method thereof. The technical problem to be solved by the invention is realized by the following technical scheme:

the embodiment of the invention provides a preparation method of a wide-swing bidirectional amplitude limiting circuit based on gallium nitride, which comprises the following steps:

s1, photoetching the first AlGaN barrier layer, and etching to remove the first AlGaN barrier layer;

s2, forming a PIN diode manufacturing region and a Schottky diode manufacturing region on the GaN layer;

s3, manufacturing the PIN diode in the PIN diode manufacturing area;

s4, manufacturing the Schottky diode in the Schottky diode manufacturing area;

s5, manufacturing a GaN-based device on the second AlGaN barrier layer;

and S6, connecting the PIN diode and the Schottky diode in parallel and then connecting the PIN diode and the Schottky diode with the GaN-based device through metal interconnection to obtain the wide-swing bidirectional amplitude limiting circuit based on the gallium nitride.

In one embodiment of the present invention, S3 includes:

s31, growing a doped N + layer on the GaN layer, growing an I layer on the N + layer, and growing a doped P + layer on the I layer;

s32, photoetching the P + layer, and evaporating metal to form a P + layer electrode;

s33, photoetching the P + layer to form a groove digging region, and etching the P + layer to the surface of the N + layer;

and S34, photoetching the N + layer, and evaporating metal to form an N + layer electrode to obtain the PIN diode.

In one embodiment of the present invention, S4 includes:

s41, epitaxially growing a doped N + type GaN layer on the GaN layer;

s42, epitaxially growing a doped N-type GaN layer on the N + type GaN layer;

s43, photoetching the N-type GaN layer and evaporating the metal stack layer to form Schottky contact, and finishing the manufacture of the N-type GaN layer electrode;

s44, etching the N + type GaN layer and the N-type GaN layer to form an etching area;

and S45, photoetching the etching area and evaporating ohmic metal to form ohmic contact, and finishing the manufacture of the N + type GaN layer electrode to obtain the Schottky diode.

In one embodiment of the present invention, S5 includes:

s51, evaporating ohmic metal on the second AlGaN barrier layer to form a source electrode and a drain electrode respectively;

s52, growing an SiN medium layer on the source electrode, the drain electrode and the second AlGaN barrier layer;

s53, manufacturing a mask on the SiN medium layer, and etching a groove;

and S54, photoetching a T-shaped gate region on the groove, and evaporating metal in the T-shaped gate region to form a gate to obtain the GaN-based device.

In one embodiment of the present invention, S6 includes:

s61, depositing a first SiN protective layer on the surfaces of the P + layer electrode and the N + layer electrode;

s62, depositing a second SiN protective layer on the surfaces of the N-type GaN layer electrode and the N + type GaN layer electrode;

s63, depositing SiO on the source electrode, the drain electrode and the grid electrode₂A protective layer;

s64, photoetching the first SiN protective layer, the second SiN protective layer and the SiO₂Forming a metal interconnection layer open hole region on the protective layer, and etching the first SiN protective layer, the second SiN protective layer and the SiO of the metal interconnection layer open hole region₂A protective layer;

S65. a first SiN protective layer, a second SiN protective layer and SiO in the metal interconnection layer open hole region₂And evaporating interconnection metal on the protective layer, connecting the PIN diode and the Schottky diode in parallel and then connecting the PIN diode and the GaN-based device to form the wide-swing bidirectional amplitude limiting circuit based on the gallium nitride.

In one embodiment of the invention, the doped N + layer has a thickness of 10 μm and a doping concentration of 1 × 10¹⁶cm^-3～1×10¹⁸cm^-3The doping element is Si; the thickness of the layer I is 20-70 mu m; the thickness of the doped P + layer is 1-10 μm, and the doping concentration is 1 × 10¹⁹cm^-3～1×10²⁰cm^-3The doping element is Mg.

In one embodiment of the present invention, the thickness of the doped N + type GaN layer is 10 μm to 40 μm, and the doping concentration is 10¹⁸～10¹⁹cm^-3(ii) a The thickness of the doped N-type GaN layer is 20-90 μm, and the doping concentration is 10¹⁴～10¹⁷cm^-3(ii) a The Schottky contact area is 1 multiplied by 10^-4cm²～4×10^-4cm²。

In one embodiment of the invention, the thickness of the SiN dielectric layer is 60nm to 120nm, and the gate length is 0.2 μm to 0.5 μm.

In an embodiment of the present invention, a thickness of the first SiN protective layer is 150nm to 200nm, and a thickness of the second SiN protective layer is 150nm to 200 nm.

In an embodiment of the present invention, a wide-swing bidirectional amplitude limiting circuit based on gallium nitride is manufactured by the method described in the above embodiment.

Compared with the prior art, the invention has the beneficial effects that:

1. the wide-swing bidirectional amplitude limiting circuit based on gallium nitride can realize the self-protection of the circuit by adopting the circuit which connects the PIN diode and the Schottky diode in parallel and then is connected with the grid layer;

2. the wide-swing bidirectional amplitude limiting circuit based on gallium nitride can meet the requirement that a device can bear the impact of forward and reverse high-power signals, and bidirectional protection of the device is realized.

Drawings

Fig. 1 is a schematic process flow diagram of a method for manufacturing a wide-swing bidirectional amplitude limiting circuit based on gallium nitride according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a wide-swing bidirectional amplitude limiting circuit based on gallium nitride according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the embodiments of the present invention are not limited thereto.