Single particle radiation resistant reinforced gallium nitride high electron mobility transistor

Abstract

The invention discloses a single particle radiation resistant reinforced gallium nitride high electron mobility transistor, which comprises a Si substrate, a GaN buffer layer, an N-type AlGaN layer arranged at a local position of a top layer in the GaN buffer layer, an AlGaN barrier layer arranged on the GaN buffer layer and the N-type AlGaN layer, a P-type GaN layer arranged above the N-type AlGaN layer and inside the AlGaN barrier layer, and a SiN passivation layer on the surface, and a drain electrode, a gate electrode, and a source electrode. According to the invention, the N-type AlGaN layer is generated below the barrier layer between the grid electrode and the drain electrode, so that the output current is improved; by generating the P-type GaN layer and the N-type AlGaN layer between the source electrode and the drain electrode, the conduction band energy level can be raised, injection of electrons from the source electrode to the buffer layer in an off state can be blocked, the leakage current of the buffer layer can be reduced, the internal electric field of the device can be weakened, collision ionization of electron-hole pairs can be reduced, the single-particle transient current can be reduced, and the radiation resistance of the device can be improved.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor devices, and in particular relates to a gallium nitride high electron mobility transistor with single particle radiation hardening. Background Art

[0002] Gallium nitride materials are widely used in automotive electronics, power supplies, 5G base stations and other fields due to their excellent properties such as wide bandgap, high temperature and high pressure resistance, and high electron saturation velocity. In addition, gallium nitride materials have unique advantages in aerospace and satellite detection fields due to their high switching frequency and power density. Due to the long-term space environment, the impact of high-energy particles in space on device reliability cannot be ignored. Studies have found that high-energy particles in space will affect the output characteristics, transfer characteristics, transconductance and other electrical characteristics of the device, and some will directly damage the structure of the device. Among them, the single particle effect is an important factor affecting the application of devices in space.

[0003] The single particle effect is caused by high-energy particles in space entering the device, generating a large number of hole-electron pairs. Under the action of the electric field, these electrons will continue to collide and ionize more hole-electron pairs inside the device. These hole-electron pairs are absorbed by the electrode through recombination, diffusion and drift, generating a large transient current, which degrades the device performance. The single particle effect will also change the characteristics of the traps in the device material, introduce leakage current between the drain and the substrate, damage the device characteristics, or cause damage between the drain and the source. In severe cases, gate breakdown may even occur. In recent years, domestic and foreign scholars have conducted research on the single particle effect through simulation software and ground simulation devices for space environments. The research found that the degradation of the device's electrical characteristics is related to the type of incident particles and the time of particle incidence.

[0004] Studies have shown that the transient current can be reduced by introducing additional electrodes to absorb electron-hole pairs in time and by changing the internal structure of the device to change the leakage current path, thereby achieving the purpose of radiation hardening. Currently, there is little research on the radiation hardening structure of GaN devices.

[0005] In the prior art, Zhou T and other scholars proposed to realize radiation-resistant hardened devices by adding grounded Schottky metal. This method uses electron beam evaporation to add grounded Schottky metal between the gate metal and the drain metal. The grounded Schottky metal can timely extract electrons generated by heavy ion radiation, reduce the transient current of the device, and enable the device to resist stronger radiation when it is in the off state; however, the Schottky metal radiation-resistant hardened structure requires an additional grounding electrode to timely discharge electrons to reduce transient current, which will make the device structure complicated and increase the difficulty of circuit design. In addition, Schottky metal will increase the on-resistance and seriously degrade the output characteristics of the device.

[0006] Neha and other scholars proposed to realize radiation-hardened devices through a double field plate structure. This method adds a long field plate to the right side of the source of the device and a short field plate to the right side of the gate to change the internal electric field distribution of the device, reduce the internal electric field of the device, reduce the generation of electron-hole pairs, and reduce the transient current generated by single particle incidence when the device is off; however, the double field plate structure will increase the area of ​​the metal electrode while changing the internal electric field distribution of the device, generate additional parasitic capacitance, and seriously degrade the high-frequency characteristics of the device, reduce the current gain cutoff frequency and the maximum oscillation frequency of the device, and affect the performance of the device and the stability during operation.

[0007] Hu X and other scholars proposed to realize radiation-hardened devices by introducing AlGaN insertion layers. This method is to insert an AlGaN insertion layer under the gallium nitride channel layer. The AlGaN insertion layer raises the conduction band energy level and acts as a back barrier, preventing the injection of electrons from the source to the buffer layer when the device is in the off state, thereby reducing the transient current. However, the AlGaN insertion layer prevents the injection of electrons from the source to the buffer layer when the device is in the off state only by introducing a new quantum well to make it difficult for electrons to be injected into the buffer layer, without reducing the peak electric field inside the device. Therefore, the transient current decreases less, and the process requirements are increased. The feasibility in actual production is low and cannot meet the needs of industrialization well.

[0008] It can be seen that the existing technology introduces field plates, AlGaN insertion layers, Schottky metals, etc. to strengthen GaN devices, but also introduces a series of reliability problems. For example, the gate field plate will produce additional parasitic capacitance, which will reduce the cutoff frequency of the device; the reinforcement effect of the AlGaN insertion layer reinforcement structure is not obvious; and the Schottky metal will have a great impact on the saturation current.

[0009] As people explore the universe more and more deeply, the damage to devices caused by high-energy particles in space is a problem that must be faced and solved, so the radiation reliability of devices in space is particularly important. Therefore, the radiation-resistant reinforcement structure of GaN devices still needs to be studied in depth. On the premise of ensuring that the device has good output characteristics, it is necessary to design a new structure device with strong resistance to single-particle effects. Summary of the invention

[0010] In order to solve the above problems existing in the prior art, the present invention provides a method for preparing a gallium nitride high electron mobility transistor with single particle radiation hardening. The technical problem to be solved by the present invention is achieved by the following technical solutions:

[0011] In a first aspect, an embodiment of the present invention provides a gallium nitride high electron mobility transistor hardened against single particle radiation, comprising:

[0012] Si substrate, a GaN buffer layer disposed on the Si substrate, an N-type AlGaN layer disposed at a local position of the top layer in the GaN buffer layer, an AlGaN barrier layer disposed on the GaN buffer layer and the N-type AlGaN layer, a P-type GaN layer disposed above the N-type AlGaN layer and inside the AlGaN barrier layer, a SiN passivation layer disposed on the AlGaN barrier layer and the P-type GaN layer, and a drain electrode, a gate electrode, and a source electrode;

[0013] The drain electrode is located outside the stacked structure composed of the AlGaN barrier layer, the P-type GaN layer, and the SiN passivation layer, on one side close to the P-type GaN layer, and the source electrode is located outside the stacked structure on the other side; the gate electrode is located inside the SiN passivation layer, on the side above the AlGaN barrier layer close to the source electrode; the lower surface of the P-type GaN layer contacts the upper surface of the N-type AlGaN layer, and the width of the P-type GaN layer is smaller than the width of the N-type AlGaN layer.

[0014] In one embodiment of the present invention, the thickness of the GaN buffer layer is 1.945 μm.

[0015] In one embodiment of the present invention, the doping concentration of the N-type AlGaN layer is 1×10 18 cm -3 , thickness is 0.01μm.

[0016] In one embodiment of the present invention, the thickness of the AlGaN barrier layer is 0.015 μm.

[0017] In one embodiment of the present invention, the doping concentration of the P-type GaN layer is 1×10 16 cm -3 , thickness is 0.015μm.

[0018] In one embodiment of the present invention, the distance between the source electrode and the drain electrode is 1.5 μm.

[0019] In one embodiment of the present invention, the distance between the source electrode and the gate electrode is 4 μm.

[0020] In a second aspect, an embodiment of the present invention provides a method for preparing a gallium nitride high electron mobility transistor with single particle radiation hardening, the method comprising:

[0021] On the Si substrate, a GaN buffer layer is epitaxially grown by metal organic chemical vapor deposition;

[0022] Making a first groove at a local position of the top layer of the grown GaN buffer layer by etching, growing AlGaN in the first groove by metal organic chemical vapor deposition, and performing ion implantation to generate an N-type AlGaN layer;

[0023] epitaxially growing an AlGaN barrier layer on the entire surface of the GaN buffer layer by metal organic chemical vapor deposition;

[0024] Making a second groove by etching at a position of the grown AlGaN barrier layer facing the N-type AlGaN layer, wherein a lower surface of the second groove contacts an upper surface of the N-type AlGaN layer, and a width of the second groove is smaller than a width of the first groove;

[0025] After growing GaN in the second groove by metal organic chemical vapor deposition, Mg ion doping is performed by ion implantation to generate a P-type GaN layer;

[0026] On the surface where the AlGaN barrier layer and the P-type GaN layer are located, SiN is deposited by a PECVD process, and a SiN passivation layer is generated by high-temperature annealing;

[0027] The source electrode region, the drain electrode region and the gate electrode region are defined by a photolithography process, and the SiN passivation layer of the source electrode region, the drain electrode region and the gate electrode region is removed by an etching process to obtain the source electrode position, the drain electrode position and the gate electrode position;

[0028] Corresponding metals are deposited at the source electrode, the drain electrode and the gate electrode by metal evaporation. The metals deposited at the source electrode and the drain electrode form ohmic contacts of the source and drain electrodes after high-temperature annealing, and the metals deposited at the gate electrode directly form Schottky contacts.

[0029] In one embodiment of the present invention, in the source electrode region, the drain electrode region and the gate electrode region defined by the photolithography process,

[0030] The drain electrode region is located outside the stacked structure consisting of the AlGaN barrier layer, the P-type GaN layer, and the SiN passivation layer, and is close to one side of the P-type GaN layer;

[0031] The source electrode region is located on the other side outside the stacked structure;

[0032] The gate electrode region is located in the SiN passivation layer and above the AlGaN barrier layer, close to a side of the source electrode region.

[0033] In one embodiment of the present invention, when ion implantation is performed to form an N-type AlGaN layer, the doping concentration is 1×10 18 cm-3 ;

[0034] When the P-type GaN layer is generated by Mg ion doping through ion implantation, the doping concentration is 1×10 16 cm -3 .

[0035] Compared with the existing radiation hardening device technology, the present invention has the following advantages:

[0036] (1) The P-type GaN layer is located at the barrier layer between the gate and the drain (i.e., the AlGaN barrier layer), which raises the energy band on the AlGaN side, that is, raises the conduction band energy level of the heterojunction, and does not affect the high-frequency characteristics of the device, so that the device has high radiation resistance while not increasing the metal electrode area to generate additional parasitic capacitance. This structure can effectively avoid the problems of increased parasitic capacitance and degradation of high-frequency characteristics of double field plate structure devices;

[0037] (2) An N-type AlGaN layer is introduced under the P-type GaN layer. The N-type AlGaN layer can compensate for the two-dimensional electron gas in the channel and increase the output current. The P-type GaN layer and the N-type AlGaN layer work together to weaken the internal electric field of the device, reduce the generation of hole-electron pairs, and reduce the single-particle transient current;

[0038] (3) The present invention does not introduce additional electrodes, optimizes the device structure, and makes the circuit design simpler. The device can well meet the practical application and still have a high radiation resistance. This structure can effectively avoid the problem that the Schottky metal structure introduces additional grounding electrodes, which makes the device structure complicated and increases the difficulty of circuit design;

[0039] (4) By changing the position, structural parameters and doping concentration of the P-type GaN layer and the N-type AlGaN layer, high radiation resistance and output characteristics can be achieved, ensuring the radiation reliability of the device and making the application field of the device more extensive. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic diagram of the structure of a gallium nitride high electron mobility transistor with single particle radiation hardening provided by an embodiment of the present invention;

[0041] Figure 2 A schematic flow chart of a method for preparing a single particle radiation hardened gallium nitride high electron mobility transistor provided by an embodiment of the present invention;

[0042] Figure 3a-3j A schematic process flow diagram of a method for preparing a single particle radiation hardened gallium nitride high electron mobility transistor provided in an embodiment of the present invention.

[0043] Reference numerals:

[0044] 1. Si substrate; 2. GaN buffer layer; 3. N-type AlGaN layer; 4. AlGaN barrier layer; 5. P-type GaN layer; 6. SiN passivation layer; 7. drain electrode; 8. gate electrode; 9. source electrode. DETAILED DESCRIPTION

[0045] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0046] Gallium nitride devices are widely used in aerospace, space exploration, satellite communications and other fields due to their excellent properties such as high switching frequency, high temperature resistance, high electron saturation velocity and high critical breakdown field strength. In the space radiation environment, high-energy particles and cosmic rays will have a huge impact on the electrical parameters of electronic devices, and may even directly cause the devices to fail permanently. For high-voltage devices, single-particle effects are a key factor affecting their space applications. At present, the radiation resistance of gallium nitride devices is usually achieved by introducing Schottky metals, field plates, and AlGaN insertion layers. These structures will bring new reliability problems and do not take into account the changes in the device's band structure and internal electric field distribution.

[0047] In view of the deficiencies in the process and structure of the above-mentioned radiation-hardened devices, based on the current technical level and process development, an embodiment of the present invention provides a single-particle radiation-hardened gallium nitride high electron mobility transistor and a method for preparing the same.

[0048] In a first aspect, an embodiment of the present invention provides a gallium nitride high electron mobility transistor with single particle radiation hardening, such as Figure 1 As shown, including:

[0049] Si substrate 1, GaN buffer layer 2 arranged on Si substrate 1, N-type AlGaN layer 3 arranged at a local position of the top layer in the GaN buffer layer 2, AlGaN barrier layer 4 arranged on the GaN buffer layer 2 and the N-type AlGaN layer 3, P-type GaN layer 5 arranged above the N-type AlGaN layer 3 and inside the AlGaN barrier layer 4, SiN passivation layer 6 arranged on the AlGaN barrier layer 4 and the P-type GaN layer 5, and drain electrode 7, gate electrode 8, source electrode 9;

[0050] Among them, the drain electrode 7 is located outside the stacked structure composed of the AlGaN barrier layer 4, the P-type GaN layer 5, and the SiN passivation layer 6, on one side close to the P-type GaN layer 5, and the source electrode 9 is located on the other side outside the stacked structure; the gate electrode 8 is located in the SiN passivation layer 6, on the side above the AlGaN barrier layer 4 close to the source electrode 9; the lower surface of the P-type GaN layer 5 contacts the upper surface of the N-type AlGaN layer 3, and the width of the P-type GaN layer 5 is smaller than the width of the N-type AlGaN layer 3.

[0051] Specifically, the thickness of the Si substrate 1 can be selected as required.

[0052] The GaN buffer layer 2 is disposed on the upper surface of the Si substrate 1, and the thickness can be selected as required. In a preferred embodiment, after adjusting the device parameters using SILVACO TCAD simulation software, the thickness of the GaN buffer layer 2 can be 1.945 μm to achieve optimal device performance.

[0053] The N-type AlGaN layer 3 is disposed at a local position of the top layer of the GaN buffer layer 2, and is formed by etching a groove in the GaN buffer layer 2, depositing AlGaN by metal organic chemical vapor deposition, and performing ion implantation of a certain concentration. Figure 1 As shown, the upper surface of the N-type AlGaN layer 3 is flush with the upper surface of the surrounding GaN buffer layer 2 , and the position of the N-type AlGaN layer 3 is close to one side edge of the GaN buffer layer 2 , and is not in the center.

[0054] The thickness and doping concentration of the N-type AlGaN layer 3 can be selected as needed. Among them, Si ions are used for doping. In a preferred embodiment, the doping concentration of the N-type AlGaN layer 3 can be 1×10 18 cm -3 , the thickness can be 0.01μm to achieve the best anti-radiation effect.

[0055] like Figure 1As shown, the AlGaN barrier layer 4 is located on the upper surfaces of the GaN buffer layer 2 and the N-type AlGaN layer 3, and the AlGaN barrier layer 4 is divided into two parts. Between the two parts of the AlGaN barrier layer 4 is a P-type GaN layer 5, and the P-type GaN layer 5 is formed by groove etching the original complete AlGaN barrier layer 4, depositing GaN by metal organic chemical vapor deposition, and then ion doping, wherein the doped ions are Mg ions; in the embodiment of the present invention, the AlGaN barrier layer 4 and the P-type GaN layer 5 have the same thickness, but it should be noted that the P-type GaN layer 5 is located directly above the N-type AlGaN layer 3, the two layers are in contact with each other, and the width of the P-type GaN layer 5 is smaller than the width of the N-type AlGaN layer 3. This is because P-type gallium nitride can raise the conduction band barrier, hinder the movement of electrons, and reduce the single-particle transient current. At the same time, the N-type aluminum gallium nitride below can improve the problem of output characteristics degradation caused by P-type doping, improve the output characteristics of the device, thereby reducing the single-particle transient current of the device, enhancing radiation resistance, and maintaining good output characteristics. In a preferred embodiment, the thickness of the AlGaN barrier layer 4 and the P-type GaN layer 5 can be 0.015μm; the doping concentration of the P-type GaN layer 5 can be 1×10 16 cm -3 , in order to achieve the best anti-radiation effect.

[0056] The SiN passivation layer 6 is located on the upper surfaces of the AlGaN barrier layer 4 and the P-type GaN layer 5 , and the thickness can be selected as required.

[0057] like Figure 1 As shown, for the stacked structure composed of the AlGaN barrier layer 4, the P-type GaN layer 5, and the SiN passivation layer 6, the drain electrode 7 is located outside the stacked structure, close to the P-type GaN layer 5, and the lower surface is in contact with the upper surface of the GaN buffer layer 2; the source electrode 9 is located outside the stacked structure, away from the P-type GaN layer 5, and the lower surface is in contact with the upper surface of the GaN buffer layer 2; the gate electrode 8 is located in the SiN passivation layer 6, the lower surface contacts the AlGaN barrier layer 4, and the gate electrode 8 is located on the side close to the source electrode 9; that is, from the spatial position, the region where the P-type GaN layer 5 and the N-type AlGaN layer 3 are located is between the gate electrode 8 and the drain electrode 7.

[0058] The spacing between the electrodes can be selected as needed. In a preferred embodiment, the spacing between the source electrode 9 and the drain electrode 7 can be 1.5 μm. The spacing between the source electrode 9 and the gate electrode 8 can be 4 μm. The above preferred parameters can achieve optimal device performance.

[0059] In order to facilitate understanding of the effect of the single-particle radiation hardened GaN high electron mobility transistor in the embodiment of the present invention, the principle thereof is described below.

[0060] Existing reinforcement structures may introduce additional electrodes, generate additional parasitic capacitance or have low radiation resistance. The radiation-resistant structure of the present invention avoids the above problems by doping inside the device, so that the present invention has high radiation resistance and high output current at the same time.

[0061] Specifically, the present invention raises the conduction band energy level of the heterojunction in the P-type GaN layer 5 between the gate electrode 8 and the drain electrode 7, so that a partial depletion region is formed near the P-type GaN layer 5 and the N-type AlGaN layer 3 when the device is in the off state. Due to the back channel effect, a large number of electrons generated from the source electrode 9 can only pass through the GaN buffer layer 2 near the P-type GaN layer 5 and the N-type AlGaN layer 3, and finally reach the drain electrode 7. Since the GaN buffer layer 2 contains a large number of acceptor defects, the electrons are constantly captured by the defects in the process of moving to the drain electrode 7, so that the number of electrons reaching the drain electrode 7 is reduced, and the transient current of the device is reduced.

[0062] The N-type AlGaN layer 3 can compensate for the two-dimensional electron gas in the channel and increase the output current of the device. At the same time, the P-type GaN layer 5 and the N-type AlGaN layer 3 will work together to reduce the internal electric field of the device, weaken the impact ionization inside the device, reduce the generation of electron-hole pairs, and reduce the single particle transient current.

[0063] The present invention changes the internal structure of the device and performs doping at appropriate positions to make it have high radiation resistance. Because the design is performed inside the device, no additional parasitic capacitance is introduced, and the high-frequency characteristics of the device are not affected, nor is the design and application of the device in the circuit affected. Under the combined action of P-type doping and N-type doping, the internal electric field of the device is weakened as a whole, which enhances the radiation reliability of the device. At the same time, N-type doping enables the device to have a higher output current. The present invention avoids the problems caused by the previous reinforcement structure, and while the device has high radiation resistance, it still has good output characteristics, thereby improving the radiation reliability of the device.

[0064] Compared with the existing radiation hardening device technology, the present invention has the following advantages:

[0065] (1) The P-type GaN layer is located at the barrier layer between the gate and the drain (i.e., the AlGaN barrier layer), which raises the energy band on the AlGaN side without affecting the high-frequency characteristics of the device, so that the device has high radiation resistance without increasing the metal electrode area to generate additional parasitic capacitance. This structure can effectively avoid the problems of increased parasitic capacitance and degradation of high-frequency characteristics of double field plate structure devices;

[0066] (2) The N-type AlGaN layer can compensate for the two-dimensional electron gas in the channel and increase the output current. The P-type GaN layer and the N-type AlGaN layer work together to weaken the internal electric field of the device, reduce the generation of hole-electron pairs, and reduce the single-particle transient current;

[0067] (3) The present invention does not introduce additional electrodes, optimizes the device structure, and makes the circuit design simpler. The device can well meet the practical application and still have a high radiation resistance. This structure can effectively avoid the problem that the Schottky metal structure introduces additional grounding electrodes, which makes the device structure complicated and increases the difficulty of circuit design;

[0068] (4) By changing the position, structural parameters and doping concentration of the P-type GaN layer and the N-type AlGaN layer, high radiation resistance and output characteristics can be achieved, ensuring the radiation reliability of the device and making the application field of the device more extensive.

[0069] In a second aspect, an embodiment of the present invention provides a method for preparing a single particle radiation hardened gallium nitride high electron mobility transistor, see Figure 2 , the method comprises the following steps:

[0070] S1, epitaxial growth of GaN buffer layer on Si substrate by metal organic chemical vapor deposition;

[0071] For this step, see Figure 3a and Figure 3b The thickness of the Si substrate and the GaN buffer layer can be selected as required.

[0072] In a preferred embodiment, the thickness of the GaN buffer layer may be 1.945 μm.

[0073] S2, forming a first groove at a local position of the top layer of the grown GaN buffer layer by an etching process, growing AlGaN in the first groove by metal organic chemical vapor deposition, and performing ion implantation to generate an N-type AlGaN layer;

[0074] For this step, see Figure 3c and Figure 3d understand.

[0075] The upper surface of the N-type AlGaN layer is flush with the upper surface of the surrounding GaN buffer layer, and the position of the N-type AlGaN layer is close to one side edge of the GaN buffer layer, and is not in the center.

[0076] The thickness and doping concentration of the N-type AlGaN layer can be selected as needed. In a preferred embodiment, when ion implantation is performed to form the N-type AlGaN layer, the doping concentration is 1×10 18 cm -3; The thickness of the N-type AlGaN layer can be 0.01μm.

[0077] S3, epitaxially growing an AlGaN barrier layer on the entire surface of the GaN buffer layer by metal organic chemical vapor deposition;

[0078] For this step, see Figure 3e understand.

[0079] The AlGaN barrier layer is located on the upper surface of the GaN buffer layer and the N-type AlGaN layer, and the thickness can be set as required. In a preferred embodiment, the thickness of the AlGaN barrier layer can be 0.015 μm.

[0080] S4, forming a second groove by etching at a position of the grown AlGaN barrier layer facing the N-type AlGaN layer, wherein a lower surface of the second groove contacts an upper surface of the N-type AlGaN layer, and a width of the second groove is smaller than a width of the first groove;

[0081] For this step, see Figure 3f understand.

[0082] S5, growing GaN in the second groove by metal organic chemical vapor deposition, and then performing Mg ion doping by ion implantation to generate a P-type GaN layer;

[0083] For this step, see Figure 3g understand.

[0084] In the embodiment of the present invention, when Mg ion doping is performed by ion implantation to generate a P-type GaN layer, the doping concentration may be 1×10 16 cm -3 The thickness of the P-type GaN layer and the AlGaN barrier layer are the same. Similarly, in a preferred embodiment, the thickness of the P-type GaN layer may be 0.015 μm;

[0085] S6, depositing SiN on the surface where the AlGaN barrier layer and the P-type GaN layer are located by a PECVD (Plasma Enhanced Chemical Vapor Deposition) process, and generating a SiN passivation layer by high temperature annealing;

[0086] For this step, see Figure 3h understand.

[0087] In this step, the high temperature annealing temperature may be 500° C., and the annealing time may be 20 min.

[0088] S7, defining the source electrode region, the drain electrode region and the gate electrode region by a photolithography process, and removing the SiN passivation layer of the source electrode region, the drain electrode region and the gate electrode region by an etching process to obtain the source electrode position, the drain electrode position and the gate electrode position;

[0089] For this step, see Figure 3i understand.

[0090] In the source electrode region, drain electrode region and gate electrode region defined by the photolithography process,

[0091] The drain electrode region is located outside the stacked structure consisting of the AlGaN barrier layer, the P-type GaN layer, and the SiN passivation layer, and is close to one side of the P-type GaN layer;

[0092] The source electrode region is located on the other side outside the stacked structure;

[0093] The gate electrode region is located in the SiN passivation layer and above the AlGaN barrier layer, close to a side of the source electrode region.

[0094] S8, depositing corresponding metals at the source electrode, the drain electrode and the gate electrode by metal evaporation, the metals deposited at the source electrode and the drain electrode form ohmic contacts of the source and drain electrodes after high-temperature annealing, and the metal deposited at the gate electrode directly forms a Schottky contact.

[0095] Among them, the metal deposited at the source electrode position can be Ti / Al / Ni / Au multilayer metal; the metal deposited at the drain electrode position can be Ti / Al / Ni / Au multilayer metal; the metal deposited at the gate electrode position can be Ni / Au multilayer metal.

[0096] The temperature for high temperature annealing of the metal deposited at the source electrode and the drain electrode may be 840° C., and the annealing time may be 30 seconds.

[0097] The device structure formed by the above processing can be seen in Figure 3j It is understood that S represents the source electrode, G represents the gate electrode, and D represents the drain electrode.

[0098] The method for preparing a gallium nitride high electron mobility transistor with single particle radiation hardening provided in an embodiment of the present invention generates an N-type AlGaN layer below the barrier layer between the gate and the drain, thereby increasing the output current; by generating a P-type GaN layer and an N-type AlGaN layer between the source and the drain, the conduction band energy level is raised, and the injection of electrons from the source to the buffer layer in the off state is blocked, thereby reducing the leakage current of the buffer layer. At the same time, it can also weaken the internal electric field of the device, reduce the collision ionization of electron-hole pairs, reduce the single particle transient current, improve the radiation resistance of the device, optimize the device structure and simplify the circuit design.

[0099] The present invention changes the barrier structure by doping inside the device, hindering the movement of electrons inside the device, increasing the time for electrons to be collected, and thus reducing the single-particle transient current. The present invention changes the structure inside the device without affecting the design and use of the device in the actual circuit, and improves the radiation resistance of the device without affecting the circuit design.

[0100] The present invention reasonably designs the position and concentration of the doping region, so that the device has high radiation resistance and still has high output current. The present invention performs N-type doping below the gate-drain region to compensate for the two-dimensional electron gas in the channel and ensure high output characteristics of the device.

[0101] The present invention does not introduce additional electrodes, simplifies the circuit design, and only performs doping inside the device, without generating additional parasitic capacitance, thereby avoiding the problem of unstable device characteristics. The P-type GaN layer and the N-type AlGaN layer in contact with the upper and lower surfaces can also reduce the electric field, reduce impact ionization inside the device, reduce the generation of electron-hole pairs, and achieve radiation hardening performance of gallium nitride-based HEMT devices.

[0102] It should be noted that, in the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and 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 operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0103] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0104] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0105] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A single-particle radiation hardened gallium nitride high electron mobility transistor, characterized in that: include: Si substrate (1), a GaN buffer layer (2) arranged on the Si substrate (1), an N-type AlGaN layer (3) arranged at a local position of the top layer in the GaN buffer layer (2), an AlGaN barrier layer (4) arranged on the GaN buffer layer (2) and the N-type AlGaN layer (3), a P-type GaN layer (5) arranged above the N-type AlGaN layer (3) and inside the AlGaN barrier layer (4), a SiN passivation layer (6) arranged on the AlGaN barrier layer (4) and the P-type GaN layer (5), and a drain electrode (7), a gate electrode (8), and a source electrode (9); The drain electrode (7) is located outside the stacked structure formed by the AlGaN barrier layer (4), the P-type GaN layer (5) and the SiN passivation layer (6), on one side close to the P-type GaN layer (5), and the source electrode (9) is located outside the stacked structure on the other side; the gate electrode (8) is located inside the SiN passivation layer (6), on the side above the AlGaN barrier layer (4) close to the source electrode (9); the lower surface of the P-type GaN layer (5) contacts the upper surface of the N-type AlGaN layer (3), and the width of the P-type GaN layer (5) is smaller than the width of the N-type AlGaN layer (3).

2. The single-event radiation hardened gallium nitride high electron mobility transistor according to claim 1, characterized in that: The thickness of the GaN buffer layer (2) is 1.945 μm.

3. The single-event radiation hardened gallium nitride high electron mobility transistor according to claim 1, characterized in that: The doping concentration of the N-type AlGaN layer (3) is 1×10 18 cm -3 , thickness is 0.01μm.

4. The single event radiation hardened gallium nitride high electron mobility transistor according to claim 1, characterized in that: The thickness of the AlGaN barrier layer (4) is 0.015 μm.

5. The single event radiation hardened gallium nitride high electron mobility transistor according to claim 1, characterized in that: The doping concentration of the P-type GaN layer (5) is 1×10 16 cm -3 , thickness is 0.015μm.

6. The single event radiation hardened gallium nitride high electron mobility transistor according to claim 1, characterized in that: The distance between the source electrode (9) and the drain electrode (7) is 1.5 μm.

7. The single event radiation hardened gallium nitride high electron mobility transistor according to claim 1, characterized in that: The distance between the source electrode (9) and the gate electrode (8) is 4 μm.

8. A method for preparing a single-particle radiation-hardened gallium nitride high electron mobility transistor, characterized in that: include: On the Si substrate, a GaN buffer layer is epitaxially grown by metal organic chemical vapor deposition; Making a first groove at a local position of the top layer of the grown GaN buffer layer by etching, growing AlGaN in the first groove by metal organic chemical vapor deposition, and performing ion implantation to generate an N-type AlGaN layer; epitaxially growing an AlGaN barrier layer on the entire surface of the GaN buffer layer by metal organic chemical vapor deposition; Making a second groove by etching at a position of the grown AlGaN barrier layer facing the N-type AlGaN layer, wherein a lower surface of the second groove contacts an upper surface of the N-type AlGaN layer, and a width of the second groove is smaller than a width of the first groove; After growing GaN in the second groove by metal organic chemical vapor deposition, Mg ion doping is performed by ion implantation to generate a P-type GaN layer; On the surface where the AlGaN barrier layer and the P-type GaN layer are located, SiN is deposited by a PECVD process, and a SiN passivation layer is generated by high-temperature annealing; The source electrode region, the drain electrode region and the gate electrode region are defined by a photolithography process, and the SiN passivation layer of the source electrode region, the drain electrode region and the gate electrode region is removed by an etching process to obtain the source electrode position, the drain electrode position and the gate electrode position; Corresponding metals are deposited at the source electrode, the drain electrode and the gate electrode by metal evaporation. The metals deposited at the source electrode and the drain electrode form ohmic contacts of the source and drain electrodes after high-temperature annealing, and the metals deposited at the gate electrode directly form Schottky contacts.

9. The method for preparing a single-particle radiation hardened gallium nitride high electron mobility transistor according to claim 8, characterized in that: In the source electrode region, drain electrode region and gate electrode region defined by the photolithography process, The drain electrode region is located outside the stacked structure consisting of the AlGaN barrier layer, the P-type GaN layer, and the SiN passivation layer, and is close to one side of the P-type GaN layer; The source electrode region is located on the other side outside the stacked structure; The gate electrode region is located in the SiN passivation layer and above the AlGaN barrier layer, close to a side of the source electrode region.

10. The method for preparing a single-particle radiation hardened gallium nitride high electron mobility transistor according to claim 8, characterized in that: When ion implantation is performed to generate an N-type AlGaN layer, the doping concentration is 1×10 18 cm -3 ; When the P-type GaN layer is generated by Mg ion doping through ion implantation, the doping concentration is 1×10 16 cm -3 .

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