A single-particle-resistant GaN HEMT device with a gate-type gate structure

Abstract

The present invention relates to a single-particle-resistant GaN HEMT device with a gate-type gate structure, belonging to the field of microelectronics. The device comprises, from bottom to top, a buffer layer, a barrier layer, a passivation layer, a source electrode, a gate electrode, and a drain electrode, and also includes a gate-type gate structure, wherein the gate-type gate structure is located below the gate electrode and above the barrier layer, and is composed of a P-GaN layer and an n-doped AlGaN layer. The present invention embeds an n-doped AlGaN layer within the P-GaN layer, introducing compensating electrons to fully recombine with a large number of holes accumulated below the gate electrode and source electrode after single-particle injection, thereby effectively suppressing electron injection from the source electrode into the channel and improving the single-particle burnout voltage of the device.

Description

Technical Field

[0001] The invention belongs to the technical field of microelectronics and relates to a single-particle resistant GaN HEMT device with a gate-type grid structure. Background Art

[0002] Gallium nitride (GaN) is a representative of the third generation of semiconductor materials. Compared with silicon or gallium arsenide, it has a wider bandgap and higher critical breakdown field strength. Its high electron mobility transistor (HEMT) has demonstrated excellent high voltage and radiation resistance. In the space radiation environment, high-energy particles and cosmic rays can have a huge impact on the electrical parameters of electronic devices, and may even directly cause permanent failure of the device. For high-voltage devices, single-particle effects are a key factor affecting their space applications. Enhancement-mode P-type nitride gate HEMTs are sensitive to single-particle effects. Conventional P-type nitride gate HEMTs generate a large number of electron-hole pairs after being incident on high-energy single particles. As the holes move toward the gate and source, they accumulate under the gate and source. These positively charged holes accumulated under the gate can reduce the potential barrier between the area under the gate and the source, allowing electrons to be injected from the source into the channel. The depletion region under the gate is reduced, causing part of the channel under the gate to open, resulting in device performance degradation or burnout [IEEE Transactions on Nuclear Science, 2013, 60(6)].

[0003] Therefore, there is an urgent need to design a single-particle-resistant enhancement-mode GaN HEMT device to reduce the accumulation of holes under the gate and source after single-particle incident, thereby preventing device burnout. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a single-event burnout-resistant GaN HEMT device with a gate-type gate structure to solve the problem of weak single-event burnout resistance of existing similar devices. An n-type AlGaN embedded layer is embedded in the P-GaN layer, so that the single-event burnout voltage of the device is improved.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A single-particle-resistant GaN HEMT device with a gate-type gate structure comprises, from bottom to top, a buffer layer 101, a barrier layer 102, and a passivation layer 103. A source 104 and a drain 106 are respectively located at the ends above the barrier layer 102. A P-GaN layer 107 is provided above the barrier layer 102 to the right of the source 104. A gate 105 is located above the P-GaN layer 107. The device is characterized in that an n-doped AlGaN layer 108 is embedded in the P-GaN layer 107, giving the P-GaN layer 107 a gate-type structure. The n-doped AlGaN layer 108 is located above the barrier layer 102 and is completely surrounded by the P-GaN layer 107 on the other three sides. The n-doped AlGaN layer 108 is located in the middle of the bottom of the P-GaN layer 107.

[0007] The device of the present invention introduces compensating electrons to fully recombine with a large number of holes gathered below the gate and source after single particle incidence, thereby effectively suppressing electron injection from the source into the channel and improving the single particle burnout voltage of the device.

[0008] Preferably, the n-doped AlGaN layer 108 has a thickness ranging from 50 nm to 150 nm, and a length ranging from 0.5 μm to 1.5 μm.

[0009] Preferably, the n-doped AlGaN layer 108 is doped with n-type impurities at a doping concentration of 4×10 18 cm -3 ~4×10 19 cm -3 .

[0010] Preferably, the thickness of the P-GaN layer 107 ranges from 100 nm to 200 nm, and the length ranges from 1.5 μm to 2 μm.

[0011] Preferably, the P-GaN layer 107 is made of AlGaN doped with P-type impurities at a doping concentration of 3×10 17 cm -3 ~2×10 19 cm -3 .

[0012] Preferably, the buffer layer 101 is made of GaN with a doping concentration of 1×10 15 cm -3 ~4×10 18 cm -3 ,

[0013] Preferably, the thickness of the buffer layer 101 ranges from 1 μm to 5 μm.

[0014] Preferably, the barrier layer 102 is made of AlGaN, and has a thickness of 15 nm to 25 nm.

[0015] Preferably, the passivation layer 103 is made of nitride, and has a thickness of 100 nm to 600 nm.

[0016] The beneficial effect of the present invention is that: by embedding an n-doped AlGaN layer in the P-GaN layer, the present invention introduces compensating electrons to fully recombine with a large number of holes accumulated below the gate and source after single particle incidence, thereby effectively suppressing the injection of electrons from the source into the channel and improving the single particle burnout voltage of the device.

[0017] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0019] Figure 1 A schematic cross-sectional view of a single-particle resistant GaN HEMT device having a gate-type gate structure according to the present invention;

[0020] Figure 2 Schematic diagram of the cross-sectional structure of a conventional enhancement-mode GaN HEMT device;

[0021] Figure 3 The conventional enhancement-mode GaN HEMT device in the off state is subjected to a single particle incident on a 2×10 -10 Hole concentration distribution at s;

[0022] Figure 4 The device of the present invention is in the off state when a single particle is incident through 2×10 -10 Hole concentration distribution at s;

[0023] Figure 5 The conventional enhancement-mode GaN HEMT device in the off state is subjected to a single particle incident on a 1×10 -9 Hole concentration distribution at s;

[0024] Figure 6 The present invention is in the off state when a single particle is incident through 1×10 -9 Hole concentration distribution at s;

[0025] Figure 7 A comparison diagram of the simulated drain current versus time curves of the present invention and conventional enhancement-mode GaN HEMT devices in the off state after single particle incident;

[0026] Reference numerals: 101 - buffer layer, 102 - barrier layer, 103 - passivation layer, 104 - source electrode, 105 - gate electrode, 106 - drain electrode, 107 - p-GaN layer, 108 - n-doped AlGaN layer. DETAILED DESCRIPTION

[0027] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0028] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the dimensions of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the accompanying drawings.

[0029] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "back", etc. indicating directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0030] See Figures 1 to 7 ,like Figure 1 As shown, an embodiment of the present invention provides a single-particle-resistant GaN HEMT device with a gate-type gate structure. From bottom to top, it includes a buffer layer 101, a barrier layer 102, a passivation layer 103, a source 104, a gate 105, a drain 106, and a gate-type gate structure. The source 104 and drain 106 are located at opposite ends of the barrier layer 102. A P-GaN layer 107 is provided on the barrier layer 102 to the right of the source, and the gate 105 is located above the P-GaN layer 107. The gate-type gate structure is located below the gate 105 and above the barrier layer 102, and consists of two parts: the P-GaN layer 107 and the n-doped AlGaN layer 108.

[0031] The thickness of the n-doped AlGaN layer 108 is 100 nm, and the length is 1 μm. The n-doped AlGaN layer 108 is doped with n-type impurities with a doping concentration of 4×10 18 cm -3 .

[0032] The P-GaN layer 107 is made of AlGaN doped with P-type impurities at a doping concentration of 4×10 18 cm -3 , the thickness is 200nm and the length is 2μm.

[0033] The buffer layer 101 is made of GaN with a doping concentration of 4×10 18 cm -3 , and its thickness is 1.975μm.

[0034] The barrier layer 102 is made of AlGaN and has a thickness of 25 nm.

[0035] The passivation layer 103 is made of nitride and has a thickness of 310 nm.

[0036] The device of this embodiment embeds an n-doped AlGaN layer 108 within the P-GaN layer 107, introducing compensating electrons to fully recombine with a large number of holes accumulated below the gate and source after single-particle incidence, thereby effectively suppressing the injection of electrons from the source into the channel and improving the single-particle burnout voltage of the device.

[0037] Figure 3 For conventional enhancement-mode GaN HEMT devices in the off state ( Figure 2 As shown) when a single particle is incident through 2×10 -10 The hole concentration distribution at s, where a single particle is incident on the gate near the drain end. It can be found that when a single particle is incident on the gate through 2×10 -10 At s, a large number of holes gather below the gate and the drain, while the hole concentration below the source is small. This is because the hole mobility is low and most of the holes have not reached the source under the action of the electric field.

[0038] Figure 4 The device of the present invention is in the off state when a single particle is incident through 2×10 -10 The hole concentration distribution at s, where a single particle is incident on the gate near the drain end. It can be found that when a single particle is incident on the gate through 2×10 -10When the current is s, the number of holes gathered under the gate and drain of the present invention is much smaller than that of the conventional device, and the hole concentration under the n-doped AlGaN layer (108) near the source is significantly lower than that in the nearby area. This is because the holes recombine with the electrons of the n-doped AlGaN layer (108) in the process of moving to the gate and the source. Since the doping concentration of the n-doped AlGaN layer (108) is relatively high, a large number of holes under it are recombined, which greatly reduces the accumulation of holes under the gate.

[0039] Figure 5 and Figure 6 They are the conventional enhancement-mode GaN HEMT devices in the off state ( Figure 2 As shown) and the device of the present invention after single particle incident 1×10 -9 The hole concentration distribution at s is shown. It can be found that after a sufficiently long time, the holes generated by impact ionization reach the source. A large number of holes accumulate under the gate-source region of the conventional enhancement-mode GaN HEMT device, while the hole concentration under the gate-source region of the present invention is significantly lower than that of the former.

[0040] Figure 7 The device of the present invention and the conventional enhancement mode GaN HEMT device ( Figure 2 (As shown in the figure), the simulation curve comparison of drain current and time after single particle incident. It can be found that when the linear energy transfer value LET of the incident single particle is 63.8MeV·cm 2 When the drain voltage is 600V, the drain current of a conventional enhancement-mode GaN HEMT device suddenly increases after a period of time and cannot be recovered, indicating a single-event burnout. However, when the drain voltage is 600V, the drain current of the device of the present invention still recovers to normal values after a period of time, and no single-event burnout occurs. Therefore, the device of the present invention has a higher single-event burnout voltage than conventional enhancement-mode GaN HEMT devices, improving the single-event burnout resistance of conventional GaN HEMT devices.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be included in the scope of the claims of the present invention.

Claims

1. A single-particle resistant GaN HEMT device with a gate-type gate structure, comprising, from bottom to top, a buffer layer (101), a barrier layer (102), and a passivation layer (103); a source electrode (104) and a drain electrode (106) are respectively located at two ends above the barrier layer (102); a P-GaN layer (107) is provided above the barrier layer (102) on the right side of the source electrode (104); and a gate electrode (105) is located above the P-GaN layer (107); characterized in that: An n-doped AlGaN layer (108) is embedded in the P-GaN layer (107), so that the P-GaN layer (107) presents a gate-type structure; the n-doped AlGaN layer (108) is located above the barrier layer (102), and the other three sides are completely surrounded by the P-GaN layer (107); the n-doped AlGaN layer (108) is located in the middle of the bottom of the P-GaN layer (107).

2. The single particle resistant GaN HEMT device according to claim 1, characterized in that: The thickness of the n-doped AlGaN layer (108) ranges from 50 nm to 150 nm, and the length ranges from 0.5 μm to 1.5 μm.

3. The single particle resistant GaN HEMT device according to claim 1 or 2, characterized in that: The n-doped AlGaN layer (108) is doped with n-type impurities with a doping concentration of 4×10 18 cm -3 ~4×10 19 cm -3 .

4. The single particle resistant GaN HEMT device according to claim 1, characterized in that: The thickness of the P-GaN layer (107) ranges from 100 nm to 200 nm, and the length ranges from 1.5 μm to 2 μm.

5. The single particle resistant GaN HEMT device according to claim 1 or 4, characterized in that: The P-GaN layer (107) is made of AlGaN doped with P-type impurities with a doping concentration of 3×10 17 cm -3 ~2×10 19 cm -3 .

6. The single particle resistant GaN HEMT device according to claim 1, characterized in that: The buffer layer (101) is made of GaN with a doping concentration of 1×10 15 cm -3 ~4×10 18 cm -3 .

7. The single particle resistant GaN HEMT device according to claim 1 or 6, characterized in that: The thickness of the buffer layer (101) ranges from 1 μm to 5 μm.

8. The single particle resistant GaN HEMT device according to claim 1, characterized in that: The barrier layer (102) is made of AlGaN and has a thickness of 15nm to 25nm.

9. The single particle resistant GaN HEMT device according to claim 1, characterized in that: The passivation layer (103) is made of nitride and has a thickness of 100nm to 600nm.

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