A GaN-based diode designed for heat dissipation through the body and a preparation method thereof
By designing a bulk heat dissipation structure in a GaN-based diode, etching grooves and filling them with thermally conductive material, and combining this with the regrowth of the AlGaN layer to form a vertical two-dimensional electron gas, the problem of insufficient heat dissipation is solved, the forward current and heat dissipation capacity of the diode are improved, and the current density and area utilization of the device are enhanced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JIANGSU CHIPPORT SEMICON CO LTD
- Filing Date
- 2023-02-07
- Publication Date
- 2026-05-12
AI Technical Summary
Existing GaN-based diodes suffer from insufficient heat dissipation, which limits their miniaturization and application, resulting in shortened lifespan and performance degradation of electronic devices in high-temperature environments.
By designing a bulk heat dissipation structure in a GaN-based diode, etching grooves and filling them with thermally conductive material, and combining this with the regrowth of the AlGaN layer to form a vertical two-dimensional electron gas, the equivalent resistance is reduced and the heat dissipation capacity is improved.
It effectively reduces the equivalent resistance of the diode, improves the forward current and heat dissipation capacity, and enhances the current density and area utilization of the device.
Smart Images
Figure CN116314257B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of microelectronic device technology, and relates to a GaN-based diode and its fabrication method, specifically to a GaN-based diode with bulk heat dissipation design and its fabrication method. Background Technology
[0002] Silicon carbide (SiC) and gallium nitride (GaN) materials, with their higher breakdown electric field, higher saturation electron velocity, higher electron density, higher thermal conductivity, higher mobility, and low dielectric constant and good electrical conductivity, can withstand higher energy densities, thus achieving higher reliability. Therefore, they are gradually gaining favor and attention from the next generation of semiconductor researchers.
[0003] While SiC was developed earlier and is more technologically mature than GaN, a significant difference lies in their thermal conductivity. This difference gives SiC greater potential in high-power applications. Meanwhile, GaN's higher electron mobility allows for faster switching speeds compared to SiC, enabling more rapid operation. These superior properties give gallium nitride a promising future in high-frequency microwave devices and solidify its position as a major player in future semiconductor material development. Therefore, GaN's future is attracting considerable attention and high expectations.
[0004] With the advent of the 5G era, gallium nitride (GaN), a new material, will play an increasingly important role and usher in its own era, experiencing explosive growth. Therefore, it will be the next protagonist in the semiconductor family, not only playing a role in military systems such as satellites, radar, communications, electronic warfare, and underwater detection, but also playing an unprecedentedly crucial role in drones, unmanned equipment, smart weapons, and new concept weapons, leading to a significant leap forward in informationized combat capabilities and major changes in the military and other fields.
[0005] However, with the advancement of modern power electronics technology, electrical products are trending towards miniaturization and compactness, leading to increased power and heat dissipation requirements for electronic devices. If the heat dissipated by electronic devices during operation cannot be dissipated in time, it can easily cause localized high temperatures, which can affect the lifespan of the electronic devices or even their performance.
[0006] However, existing GaN-based diodes suffer from insufficient heat dissipation capabilities, which significantly limits their miniaturization and application.
[0007] In view of the above-mentioned technical defects of the prior art, there is a need to provide an improved GaN-based diode and its fabrication method to overcome the above defects. Summary of the Invention
[0008] To overcome the shortcomings of existing technologies, this invention proposes a GaN-based diode with bulk heat dissipation design and its fabrication method, which can effectively reduce n - - The equivalent resistance of the GaN transport layer increases the forward current of the diode; at the same time, filling the space between each conductive unit with thermally conductive material improves the heat dissipation capacity of the diode.
[0009] To achieve the above objectives, the present invention provides the following technical solution:
[0010] A method for fabricating a GaN-based diode with bulk heat dissipation design, characterized by comprising the following steps:
[0011] 1) In N + - An N layer is grown on the front side of the GaN layer. - -GaN transport layer;
[0012] 2) In the N + -GaN layer and N - -Etching grooves on the GaN transport layer, the width of the grooves being 4–10 μm and the depth being such that the N... + - The GaN layer was etched away by 100-500 nm;
[0013] 3) Grow an AlGaN layer with a thickness of 10-30 nm throughout;
[0014] 4) Deposit thermally conductive material on the AlGaN layer;
[0015] 5) Polish the thermally conductive material to remove the thermally conductive material above the AlGaN layer, leaving only the thermally conductive material located in the groove, and make the top surface of the remaining thermally conductive material flush with the top surface of the AlGaN layer.
[0016] 6) In the N + - The cathode is fabricated on the bottom surface of the GaN layer;
[0017] 7) An anode is fabricated on the thermally conductive material and part of the AlGaN layer.
[0018] Preferably, the Al composition of the AlGaN layer is 15% to 40%.
[0019] Preferably, the AlGaN layer and the N - - A two-dimensional electron gas is formed between GaN layers in the vertical direction, but not in the horizontal direction.
[0020] Preferably, the thermally conductive material is thermally conductive silicone grease or phase change thermal paste.
[0021] Preferably, the cathode is composed of a Ti layer, an Al layer, a Ni layer and an Au layer stacked together, wherein the thickness of the Ti layer is 20 nm, the thickness of the Al layer is 160 nm, the thickness of the Ni layer is 55 nm and the thickness of the Au layer is 45 nm.
[0022] Preferably, after step 5), a rapid metal annealing process is performed first, followed by step 6), wherein the rapid metal annealing process is a rapid thermal annealing at 870°C in a N2 atmosphere for 30 seconds.
[0023] Preferably, the anode is composed of a Ni layer and an Au layer stacked together, wherein the Ni layer has a thickness of 45 nm and the Au layer has a thickness of 200 nm.
[0024] Furthermore, the present invention also provides a GaN-based diode with a bulk heat dissipation design, characterized in that it is prepared using the above-described preparation method.
[0025] Compared with the prior art, the GaN-based diode with bulk heat dissipation design and its fabrication method of the present invention have one or more of the following beneficial technical effects:
[0026] 1. In the GaN-based diode with a vertical AlGaN / GaN heterojunction designed for bulk heat dissipation according to the present invention, 2DEG is formed in the vertical direction by regrowing an AlGaN layer, which can effectively reduce N - - The equivalent resistance of the GaN transport layer increases the forward current of the diode.
[0027] 2. The GaN-based diode with a vertical AlGaN / GaN heterojunction designed for heat dissipation in this invention fills the space between each conductive unit with thermally conductive material, thereby improving the diode's heat dissipation capability.
[0028] 3. Compared with the horizontal conductivity of traditional AlGaN / GaN diodes, this invention adopts vertical 2DEG channel conductivity, which increases the current density per unit area and improves the area utilization of the diode. Attached Figure Description
[0029] Figure 1 It is N + -Schematic diagram of the GaN layer structure.
[0030] Figure 2 Is Figure 1 N was grown on the basis - -Schematic diagram of the structure behind the GaN layer.
[0031] Figure 3 Is Figure 2 The diagram shows the structure after the grooves were etched.
[0032] Figure 4 Is Figure 3 This is a schematic diagram of the structure after an AlGaN layer has been grown on top of the existing structure.
[0033] Figure 5 Is Figure 4 This is a schematic diagram of the structure after thermally conductive material has been deposited on top of the existing structure.
[0034] Figure 6 Is Figure 5 A schematic diagram of the structure after polishing was provided based on the above.
[0035] Figure 7 Is Figure 6 Based on this, a schematic diagram of the structure after the cathode was created.
[0036] Figure 8 Is Figure 7 Based on this, a schematic diagram of the structure after anode was created. Detailed Implementation
[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments. The content of the embodiments is not intended to limit the scope of protection of the present invention.
[0038] This invention relates to a GaN-based diode with bulk heat dissipation design and its fabrication method, which can effectively reduce n - - The equivalent resistance of the GaN transport layer increases the forward current of the diode; at the same time, filling the space between each conductive unit with thermally conductive material improves the heat dissipation capacity of the diode.
[0039] The method for fabricating a GaN-based diode with bulk heat dissipation design according to the present invention includes the following steps:
[0040] I. For example Figure 1 As shown, provide an N + -GaN layer 1.
[0041] In this invention, the N + -GaN layer 1 serves as the substrate. Preferably, the N... + - The thickness of GaN layer 1 is 1 to 4 μm.
[0042] II. Figure 2 As shown, in the N + - An N layer is grown on the front side of the GaN layer. - -GaN transport layer 2. The N - -GaN transport layer 2 is a drift layer. Preferably, the N... - - The thickness of GaN transport layer 2 is 3 to 9 μm.
[0043] Similar to existing technologies, in this invention, the N can be grown using an MOCVD (metal-organic chemical vapor deposition) process. - -GaN transport layer 2.
[0044] III. Figure 3 As shown, in the N + -GaN layer 1 and N - -Etched groove a on GaN layer 2.
[0045] In this invention, the groove a can be etched using ICP (inductively coupled plasma) etching technology.
[0046] During etching, the width of the groove a is set to 4–10 μm. Furthermore, the depth of the groove a is set such that the N... + - The GaN layer 1 is etched away to a depth of 100-500 nm, that is, after etching away the N... - After the GaN transport layer 2, a portion of the N layer thickness is etched away. + -GaN layer 1, and make the N + The etching thickness of GaN layer 1 is 100-500 nm.
[0047] IV. Figure 4 As shown, an AlGaN layer with a thickness of 10–30 nm is grown throughout the structure.
[0048] In this invention, the AlGaN layer 3 can also be grown using MOCVD (metal-organic chemical vapor deposition) technology. The AlGaN layer 3 must cover the N... - -GaN layer 2 and the bottom and sides of the groove a.
[0049] Preferably, during growth, the Al composition of the AlGaN layer is controlled to be 15% to 40%.
[0050] In this invention, an AlGaN / GaN heterojunction is formed by regrowing the AlGaN layer 3, and the AlGaN layer 3 is connected to the N... - - The GaN transport layer 2 forms a 2DEG (two-dimensional electron gas) b in the vertical direction, but not in the horizontal direction. This reduces the N... - The equivalent resistance of the GaN transport layer 2 increases the forward current density of the diode. Simultaneously, the higher electron mobility of 2DEG results in better frequency characteristics for the diode.
[0051] V. For example Figure 5 As shown, thermally conductive material 4 is deposited on the AlGaN layer 3.
[0052] During the deposition of the thermally conductive material 4, the thermally conductive material 4 fills the groove a and is deposited on the entire surface of the device, resulting in a wavy growth pattern on the surface.
[0053] Preferably, the thermally conductive material 4 is thermally conductive silicone grease or phase change thermal paste.
[0054] VI. For example Figure 6 As shown, the thermally conductive material 4 is polished to remove the thermally conductive material 4 above the AlGaN layer 3, leaving only the thermally conductive material 4 located in the groove a, and making the top surface of the remaining thermally conductive material 4 flush with the top surface of the AlGaN layer 3.
[0055] In this invention, since the surface of the device after the thermally conductive material is grown is uneven and wavy, a polishing machine is used to treat the surface of the device to make it smooth.
[0056] VII. For example Figure 7 As shown, in the N + A cathode 5 is fabricated on the bottom surface of GaN layer 1.
[0057] In this invention, preferably, the cathode 5 is composed of a Ti layer, an Al layer, a Ni layer and an Au layer stacked together, wherein the thickness of the Ti layer is 20 nm, the thickness of the Al layer is 160 nm, the thickness of the Ni layer is 55 nm and the thickness of the Au layer is 45 nm.
[0058] More preferably, after the cathode 5 is fabricated, a rapid metal annealing process is performed. This rapid metal annealing process involves rapid thermal annealing at 870°C in a N2 atmosphere for 30 seconds. Through this rapid metal annealing process, the ohmic contact metal used to fabricate the cathode 5 can be alloyed, facilitating the fabrication of the cathode 5.
[0059] 8. For example Figure 8 As shown, an anode 6 is fabricated on the thermally conductive material 4 and part of the AlGaN layer 3.
[0060] Preferably, the anode 6 is formed by stacking a Ni layer and an Au layer. The Ni layer has a thickness of 45 nm, and the Au layer has a thickness of 200 nm.
[0061] The present invention is described in more detail below with reference to several specific embodiments, so that those skilled in the art can implement the fabrication of the GaN-based diode with the described bulk heat dissipation design according to the present invention.
[0062] The following embodiments have AlGaN layers of different thicknesses, grooves a of different widths, and different thermally conductive materials, but are otherwise identical.
[0063]
Example 1
[0064] In this embodiment, thermally conductive silicone grease is used as the thermally conductive material, the thickness of the regrown AlGaN layer 3 is 20 nm, the Al composition is 20%, and the width of the groove a is 5 μm.
[0065] Therefore, the fabrication method of the GaN-based diode with bulk heat dissipation design in this embodiment includes the following steps:
[0066] Step 1. Epitaxial material growth.
[0067] 1.1) Select N + -GaN layer 1;
[0068] 1.2) In the N + - On GaN layer 1, perform epitaxial growth to grow an N layer. - -GaN transport layer 2.
[0069] Step 2. Fabrication of deposition grooves.
[0070] 2.1) First, a spin coater is used to spin the photoresist at a speed of 3500 rpm to obtain a photoresist mask; then, an NSR1755I7A lithography machine is used for exposure to form a mask pattern of the active area of the mesa.
[0071] 2.2) Then, the substrate with the mask prepared is etched with Cl2 plasma at an etching rate of 20 nm / s using an ICP98c inductively coupled plasma etching machine to form groove a, wherein the width of groove a is 5 μm.
[0072] Step 3. Growth of material within the groove.
[0073] 3.1) First, AlGaN layer 3 is regrown in the groove a, so that the grown AlGaN uniformly covers the bottom and sidewalls of the groove a. The thickness of the regrown AlGaN layer 3 is 20nm and the Al composition is 20%.
[0074] 3.2) Next, after the AlGaN layer 3 is regrown, thermal conductive material 4 is deposited on the entire device surface. The selected thermal conductive material is thermal conductive grease, and a wavy growth result appears on the surface.
[0075] Step 4. Grind the surface material of the device.
[0076] After the thermally conductive material 4 is grown, the surface of the device is uneven and wavy. At this time, a polishing machine is used to treat the surface of the device to make it smooth.
[0077] Step 5. Fabrication of cathode 5.
[0078] First, a photoresist mask with a thickness of 0.8 μm was obtained by spinning the photoresist mask at a speed of 5000 rpm.
[0079] Next, it was baked in a high-temperature oven at 80°C for 10 minutes, and then exposed using an NSR1755I7A lithography machine to form the area mask pattern of cathode 5.
[0080] Then, cathode 5 was fabricated using an Ohmiker-50 electron beam evaporation stage at an evaporation rate of 0.1 nm / s. The cathode metals were Ti / Al / Ni / Au in sequence, with Ti having a thickness of 20 nm, Al having a thickness of 160 nm, Ni having a thickness of 55 nm, and Au having a thickness of 45 nm. After the ohmic contact metal was evaporated, the metal was stripped to obtain a complete cathode 5.
[0081] Finally, the ohmic contact metal is alloyed by rapidly annealing in an N2 atmosphere at 870°C for 30 seconds using an RTP500 rapid thermal annealing furnace to complete the fabrication of cathode 5.
[0082] Step 6. Fabrication of Anode 6.
[0083] First, a photoresist mask with a thickness of 0.8 μm was obtained by spinning the photoresist mask at a speed of 5000 rpm.
[0084] Next, it was baked in a high-temperature oven at 80°C for 10 minutes, and then exposed using an NSR1755I7A lithography machine to form the mask pattern of the anode 6 area;
[0085] Finally, the anode metal was evaporated using an Ohmiker-50 electron beam evaporation stage at an evaporation rate of 0.1 nm / s. The anode metal was selected as Ni / Au, with a Ni thickness of 45 nm and an Au thickness of 200 nm. After evaporation, the metal was stripped to obtain a complete anode 6.
[0086]
Example 2
[0087] In this embodiment, thermally conductive silicone grease is used as the thermally conductive material, the thickness of the regrown AlGaN layer 3 is 30 nm, the Al composition is 40%, and the width of the groove a is 8 μm.
[0088] Therefore, the fabrication method of the GaN-based diode with bulk heat dissipation design in this embodiment includes the following steps:
[0089] Step 1. Epitaxial material growth.
[0090] 1.1) Select N + -GaN layer 1 serves as the substrate;
[0091] 1.2) In N +- On GaN layer 1, perform epitaxial growth to grow an N layer. - -GaN transport layer 2.
[0092] Step 2. Fabrication of deposition groove a.
[0093] 2.1) First, a spin coater is used to spin the photoresist at a speed of 3500 rpm to obtain a photoresist mask; then, an NSR1755I7A lithography machine is used for exposure to form a mask pattern of the active area of the mesa.
[0094] 2.2) Then, the substrate with the mask is etched with Cl2 plasma at an etching rate of 20 nm / s to form groove a, the width of which is 8 μm.
[0095] Step 3. Growth of material within the groove.
[0096] 3.1) First, AlGaN layer 3 is regrown in the groove a so that the grown AlGaN uniformly covers the bottom and sidewalls of the groove a. The thickness of the regrown AlGaN layer 3 is 30nm and the Al composition is 40%.
[0097] 3.2) Next, after the AlGaN layer 3 is regrown, thermal conductive material 4 is deposited on the entire device surface. The selected thermal conductive material is thermal conductive grease, and a wavy growth result appears on the surface.
[0098] Step 4. Grind the surface material of the device.
[0099] After the thermally conductive material 4 is grown, the surface of the device is uneven and wavy. At this time, a polishing machine is used to treat the surface of the device to make it smooth.
[0100] Step 5. Fabrication of cathode 5.
[0101] First, a photoresist mask with a thickness of 0.8 μm was obtained by spinning the photoresist mask at a speed of 5000 rpm.
[0102] Next, it was baked in a high-temperature oven at 80°C for 10 minutes, and then exposed using an NSR1755I7A lithography machine to form the area mask pattern of cathode 5.
[0103] Then, cathode 5 was fabricated using an Ohmiker-50 electron beam evaporation stage at an evaporation rate of 0.1 nm / s. The cathode metals were Ti / Al / Ni / Au in sequence, with Ti having a thickness of 20 nm, Al having a thickness of 160 nm, Ni having a thickness of 55 nm, and Au having a thickness of 45 nm. After the ohmic contact metal was evaporated, the metal was stripped to obtain a complete cathode 5.
[0104] Finally, the ohmic contact metal is alloyed by rapidly annealing in an N2 atmosphere at 870°C for 30 seconds using an RTP500 rapid thermal annealing furnace to complete the fabrication of cathode 5.
[0105] Step 6. Fabrication of Anode 6.
[0106] First, a photoresist mask with a thickness of 0.8 μm was obtained by spinning the photoresist mask at a speed of 5000 rpm.
[0107] Next, it was baked in a high-temperature oven at 80°C for 10 minutes, and then exposed using an NSR1755I7A lithography machine to form the mask pattern of the anode 6 area;
[0108] Finally, the anode metal was evaporated using an Ohmiker-50 electron beam evaporation stage at an evaporation rate of 0.1 nm / s. The anode metal was selected as Ni / Au, with a Ni thickness of 45 nm and an Au thickness of 200 nm. After evaporation, the metal was stripped to obtain a complete anode 6.
[0109]
Example 3
[0110] In this embodiment, phase change thermal paste is used as the thermal conductive material, the thickness of the regrown AlGaN layer 3 is 20 nm, the Al composition is 20%, and the width of the groove a is 5 μm.
[0111] Therefore, the fabrication method of the GaN-based diode with bulk heat dissipation design in this embodiment includes the following steps:
[0112] Step 1. Epitaxial material growth.
[0113] 1.1) Select N + -GaN layer 1 serves as the substrate;
[0114] 1.2) In N + - On GaN layer 1, perform epitaxial growth to grow an N layer. - -GaN transport layer 2.
[0115] Step 2. Fabrication of deposition groove a.
[0116] 2.1) First, a spin coater is used to spin the photoresist at a speed of 3500 rpm to obtain a photoresist mask; then, an NSR1755I7A lithography machine is used for exposure to form a mask pattern of the active area of the mesa.
[0117] 2.2) Then, the substrate with the mask is etched with Cl2 plasma at an etching rate of 20 nm / s to form groove a, the width of which is 5 μm.
[0118] Step 3. Growth of material within the groove.
[0119] 3.1) First, AlGaN layer 3 is regrown in the groove a so that the grown AlGaN uniformly covers the bottom and sidewalls of the groove a. The thickness of the regrown AlGaN layer 3 is 20nm and the Al composition is 20%.
[0120] 3.2) Next, after the AlGaN layer 3 is regrown, thermal conductive material 4 is deposited on the entire device surface. The selected thermal conductive material is phase change thermal paste, and a wavy growth result appears on the surface.
[0121] Step 4. Grind the surface material of the device.
[0122] After the thermally conductive material 4 is grown, the surface of the device is uneven and wavy. At this time, a polishing machine is used to treat the surface of the device to make it smooth.
[0123] Step 5. Fabrication of cathode 5.
[0124] First, a photoresist mask with a thickness of 0.8 μm was obtained by spinning the photoresist mask at a speed of 5000 rpm.
[0125] Next, it was baked in a high-temperature oven at 80°C for 10 minutes, and then exposed using an NSR1755I7A lithography machine to form the area mask pattern of cathode 5.
[0126] Then, cathode 5 was fabricated using an Ohmiker-50 electron beam evaporation stage at an evaporation rate of 0.1 nm / s. The cathode metals were Ti / Al / Ni / Au in sequence, with Ti having a thickness of 20 nm, Al having a thickness of 160 nm, Ni having a thickness of 55 nm, and Au having a thickness of 45 nm. After the ohmic contact metal was evaporated, the metal was stripped to obtain a complete cathode 5.
[0127] Finally, the ohmic contact metal is alloyed by rapidly annealing in an N2 atmosphere at 870°C for 30 seconds using an RTP500 rapid thermal annealing furnace to complete the fabrication of cathode 5.
[0128] Step 6. Fabrication of Anode 6.
[0129] First, a photoresist mask with a thickness of 0.8 μm was obtained by spinning the photoresist mask at a speed of 5000 rpm.
[0130] Next, it was baked in a high-temperature oven at 80°C for 10 minutes, and then exposed using an NSR1755I7A lithography machine to form the mask pattern of the anode 6 area;
[0131] Finally, the anode metal was evaporated using an Ohmiker-50 electron beam evaporation stage at an evaporation rate of 0.1 nm / s. The anode metal was selected as Ni / Au, with a Ni thickness of 45 nm and an Au thickness of 200 nm. After evaporation, the metal was stripped to obtain a complete anode 6.
[0132] The GaN-based diode of the present invention, with its vertical AlGaN / GaN heterojunction heat dissipation design, utilizes a regrown AlGaN layer to form a 2DEG in the vertical direction, which can effectively reduce N... - The equivalent resistance of the GaN transport layer increases the forward current of the diode. Simultaneously, filling the spaces between each conductive unit with thermally conductive material improves the diode's heat dissipation capacity. Finally, the invention employs a vertical 2DEG channel for conduction, increasing the current density per unit area and improving the diode's area utilization.
[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Those skilled in the art can modify or make equivalent substitutions to the technical solutions of the present invention based on the concept of the present invention, without departing from the essence and scope of the technical solutions of the present invention.
Claims
1. A method for fabricating a GaN-based diode with bulk heat dissipation design, characterized in that, Includes the following steps: 1) In N + - An N layer is grown on the front side of the GaN layer (1). - -GaN transport layer (2); 2) In the N + -GaN layer (1) and N - - A groove (a) is etched on the GaN transport layer (2), the width of the groove (a) being 4~10μm and the depth being such that the N... + - The GaN layer (1) is etched away by 100~500 nm; 3) Grow an AlGaN layer with a thickness of 10~30nm as a whole (3); 4) Deposit thermally conductive material (4) on the AlGaN layer (3); 5) Polish the thermally conductive material (4) to remove the thermally conductive material (4) above the AlGaN layer (3), leaving only the thermally conductive material (4) in the groove (a), and make the top surface of the remaining thermally conductive material (4) flush with the top surface of the AlGaN layer (3); 6) In the N + - A cathode (5) is fabricated on the bottom surface of the GaN layer (1); 7) An anode (6) is fabricated on the thermally conductive material (4) and part of the AlGaN layer (3).
2. The method for fabricating a GaN-based diode with bulk heat dissipation design according to claim 1, characterized in that, The Al composition of the AlGaN layer (3) is 15%~40%.
3. The method for fabricating a GaN-based diode with bulk heat dissipation design according to claim 2, characterized in that, The AlGaN layer (3) and the N - - A two-dimensional electron gas (b) is formed between the GaN transport layers (2) in the vertical direction, but no two-dimensional electron gas is formed in the horizontal direction.
4. The method for fabricating a GaN-based diode with bulk heat dissipation design according to claim 3, characterized in that, The thermally conductive material (4) is thermally conductive silicone grease or phase change thermal paste.
5. The method for fabricating a GaN-based diode with bulk heat dissipation design according to claim 4, characterized in that, The cathode (5) is composed of a Ti layer, an Al layer, a Ni layer and an Au layer stacked together, wherein the thickness of the Ti layer of the cathode (5) is 20 nm, the thickness of the Al layer is 160 nm, the thickness of the Ni layer is 55 nm and the thickness of the Au layer is 45 nm.
6. The method for fabricating a GaN-based diode with bulk heat dissipation design according to claim 5, characterized in that, After step 5), a rapid metal annealing process is performed first, followed by step 6), where the rapid metal annealing process is a rapid thermal annealing at 870°C in a N2 atmosphere for 30 seconds.
7. The method for fabricating a GaN-based diode with bulk heat dissipation design according to claim 6, characterized in that, The anode (6) is made of a Ni layer and an Au layer stacked together, wherein the thickness of the Ni layer of the anode (6) is 45 nm and the thickness of the Au layer of the anode (6) is 200 nm.
8. A GaN-based diode with a bulk heat dissipation design, characterized in that, It is prepared using the preparation method described in any one of claims 1-7.