A diamond-based lateral HEMT device and method of manufacturing the same

Abstract

The application discloses a diamond-based lateral HEMT device and a manufacturing method thereof, which comprises, from bottom to top, a non-polar insulating substrate, a buffer layer, an AL-diamond layer, and a source, a gate and a drain formed on the AL-diamond layer, wherein the non-polar insulating substrate and the buffer layer are made of diamond. The device has simple structure, simple manufacturing process and low cost. Since the diamond has good heat conduction property, an additional heat dissipation device is not needed, the volume of the device and subsequent working module is saved, and the power density is improved.

Description

Technical Field

[0001] This application relates to a diamond-based lateral HEMT device and a method for manufacturing the same. Background Technology

[0002] Diamond devices have attracted widespread attention and research due to their superior physical properties. Regarded as a leading example of ultra-wide bandgap semiconductors, they possess many characteristics unmatched by other materials. However, their applications are primarily focused on substrate heat dissipation and basic diamond diodes, with limited development of subsequent devices, failing to fully utilize their advantages of simple device structure and manufacturing processes. Summary of the Invention

[0003] The main objective of this application is to provide a diamond-based lateral HEMT device with a simple structure, simple manufacturing process, and low cost.

[0004] To achieve the aforementioned objectives, the technical solution adopted in this application includes: a diamond-based lateral HEMT device, which, from bottom to top, comprises an undoped insulating substrate, a buffer layer, an AL-diamond layer, and a source, a gate, and a drain formed on the AL-diamond layer, wherein the undoped insulating substrate and the buffer layer are made of diamond.

[0005] In another optimization method, the thickness of the undoped insulating substrate is 300~500μm.

[0006] Another optimization method involves depositing the buffer layer to a thickness of 100~300μm.

[0007] Another optimization method involves depositing the AL-diamond layer to a thickness of 100~300μm.

[0008] Another optimization method involves depositing the source, gate, and drain electrodes with a thickness of 10–50 μm.

[0009] This invention provides a method for producing the aforementioned diamond-based lateral HEMT device, comprising the following steps:

[0010] Step 1: Deposit a buffer layer on an undoped insulating substrate made of diamond.

[0011] Step 2: Deposit an Al-diamond layer on the buffer layer;

[0012] Step 3: Deposit a first barrier layer by chemical vapor deposition on the Al-diamond layer, apply photoresist to the first barrier layer, partially expose the photoresist at both ends of the first barrier layer, remove the exposed photoresist with photolithography solution and then etch the first barrier layer to form a first via, deposit the source and drain through the first via to form the source and drain.

[0013] Step 4: An N-channel region is formed on the Al-diamond layer. A second barrier layer is deposited by chemical vapor deposition above the N-channel region and the source and drain. Photoresist is coated on the second barrier layer. The second via portion of the photoresist is exposed. The exposed photoresist is removed by photolithography solution, and the second barrier layer is etched to form the second via. The gate region is deposited through the second via region to form the gate.

[0014] Another optimization method involves physical vapor deposition in step 1, using a target material with a doping concentration of 2*10^17 cm⁻¹. -3 ~4*10^17cm -3 N-type diamond material, with a deposition thickness of 100~300μm.

[0015] Another optimization method is to use physical vapor deposition to deposit the Al-diamond layer in step 2, with Al and diamond as the target materials, and the ratio of the two is 1:9 to 3:7.

[0016] Another optimization method involves depositing Au metal at the source and drain electrodes in step 3, using physical vapor deposition, with a deposition thickness of 10~50μm.

[0017] Another optimization method is to use Au as the gate metal in step 4, and the deposition method is physical vapor deposition, with a deposition thickness of 10~50μm.

[0018] Compared with the prior art, this application has the following advantages: the device has a simple structure, simple manufacturing process, and low cost. Due to the good thermal conductivity of diamond, no additional heat dissipation device is required, which saves the volume of the device and subsequent working modules and improves the power density. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the undoped insulating substrate and buffer layer after step 1;

[0020] Figure 2 This is a schematic diagram of the structure of the undoped insulating substrate, buffer layer, and AL-diamond layer after step 2;

[0021] Figure 3 This is a schematic diagram of the structure of the undoped insulating substrate buffer layer, AL-diamond layer, source and drain after step 3;

[0022] Figure 4 This is a schematic diagram of the structure of the lateral HEMT device after step 4. Detailed Implementation

[0023] Reference Figure 1-4 As shown, the diamond-based lateral HEMT device, from bottom to top, includes an undoped insulating substrate, a buffer layer, an AL-diamond layer, and source, gate, and drain electrodes formed on the AL-diamond layer. The undoped insulating substrate and the buffer layer are made of diamond. The thickness of the undoped insulating substrate is 300-500 μm. The deposition thickness of the buffer layer is 100-300 μm. The deposition thickness of the AL-diamond layer is 100-300 μm. The deposition thickness of the source, gate, and drain electrodes is 10-50 μm.

[0024] A method for producing the aforementioned diamond-based lateral HEMT device includes the following steps:

[0025] Step 1: Using an undoped insulating substrate made of diamond, a buffer layer is deposited on the undoped insulating substrate by physical vapor deposition. The target material is a doped material with a doping concentration of 2*10^17 cm⁻¹. -3 ~4*10^17cm -3 N-type diamond material, with a deposition thickness of 100~300μm;

[0026] Step 2: An Al-diamond layer is deposited on the buffer layer. The Al-diamond layer is deposited by physical vapor deposition. The target material is Al and diamond, and the ratio of the two is 1:9 to 3:7.

[0027] Step 3: A first barrier layer is chemically vapor-deposited above the Al-diamond layer. Photoresist is applied to the first barrier layer. The photoresist at both ends of the first barrier layer is partially exposed. The exposed photoresist is removed using a photolithography solution, and then the first barrier layer is etched to form a first via. The source and drain electrodes are deposited through the first via to form the source and drain electrodes. The source and drain electrodes are deposited with Au metal. The deposition method is physical vapor deposition, and the deposition thickness is 10~50μm.

[0028] Step 4: An N-channel region is formed on the Al-diamond layer. A second barrier layer is deposited by chemical vapor deposition above the N-channel region and the source and drain electrodes. Photoresist is coated on the second barrier layer. The second via portion of the photoresist is exposed, and the exposed photoresist is removed by photolithography solution to etch the second barrier layer, forming the second via. The gate region is deposited through the second via region to form the gate. The gate deposited metal is Au, and the deposition method is physical vapor deposition, with a deposition thickness of 10~50μm.

[0029] This lateral HEMT device employs a lateral structure, with conductivity primarily relying on a two-dimensional electron gas. This electron gas is generated by the bandgap difference between the Al-diamond layer and the buffer layer. This bandgap difference is mainly achieved by adjusting the Al content in the Al-diamond layer, thereby adjusting the bandgap of the Al-diamond layer and consequently the bandgap difference. The operating mode of the device can be adjusted by changing the Al content in the Al-diamond layer, enabling both enhancement-mode and depletion-mode operation.

[0030] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A diamond-based lateral HEMT device, characterized in that: It comprises, from bottom to top, an undoped insulating substrate, a buffer layer, an Al-diamond layer, and a source, a gate, and a drain formed on the Al-diamond layer. The undoped insulating substrate and the buffer layer are made of diamond. The Al-diamond layer is deposited by physical vapor deposition, and the target material is Al and diamond in a ratio of 1:9 to 3:

7.

2. The diamond-based lateral HEMT device according to claim 1, characterized in that: The thickness of the undoped insulating substrate is 300~500μm.

3. The diamond-based lateral HEMT device according to claim 1, characterized in that: The deposition thickness of the buffer layer is 100~300μm.

4. The diamond-based lateral HEMT device according to claim 1, characterized in that: The deposition thickness of the Al-diamond layer is 100~300μm.

5. The diamond-based lateral HEMT device according to claim 1, characterized in that: The deposition thickness of the source, gate, and drain is 10~50μm.

6. A method for producing a diamond-based lateral HEMT device according to any one of claims 1-5, characterized in that, It includes the following steps: Step 1: Deposit a buffer layer on an undoped insulating substrate made of diamond. Step 2: Deposit an Al-diamond layer on the buffer layer; Step 3: Deposit a first barrier layer by chemical vapor deposition on the Al-diamond layer, apply photoresist to the first barrier layer, partially expose the photoresist at both ends of the first barrier layer, remove the exposed photoresist with photolithography solution and then etch the first barrier layer to form a first via, deposit the source and drain through the first via to form the source and drain. Step 4: An N-channel region is formed on the Al-diamond layer. A second barrier layer is deposited by chemical vapor deposition above the N-channel region and the source and drain. Photoresist is coated on the second barrier layer. The second via portion of the photoresist is exposed. The exposed photoresist is removed by photolithography solution, and the second barrier layer is etched to form the second via. The gate region is deposited through the second via region to form the gate.

7. The method according to claim 6, characterized in that: In step 1, the deposition method is physical vapor deposition, and the target material has a doping concentration of 2*10^17 cm⁻¹. -3 ~4*10^17cm -3 N-type diamond material, with a deposition thickness of 100~300μm.

8. The method according to claim 6, characterized in that: In step 3, Au is deposited on the source and drain electrodes using physical vapor deposition, with a deposition thickness of 10~50μm.

9. The method according to claim 6, characterized in that: In step 4, the gate metal is Au, the deposition method is physical vapor deposition, and the deposition thickness is 10~50μm.

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