A method for preparing a TMBS device

Abstract

The present invention relates to the field of semiconductors, and in particular to a method for preparing a TMBS device, comprising the following steps: step 1, using a single crystal silicon material as a substrate material; step 2, forming an indium nitride buffer layer on the upper surface of the substrate base by chemical vapor deposition; step 3, growing a layer of indium germanium antimonide as an epitaxial layer on the surface of the buffer layer by chemical vapor deposition; step 4, opening a groove; step 5, setting a Schottky barrier and a metal layer, and obtaining the desired TMBS device. The epitaxial layer used in the present invention is indium germanium antimonide, which has lower surface defects and better breakdown resistance than indium antimonide, so that the TMBS device has a wide range of application prospects in the fields of power electronics, new energy vehicles, and photovoltaics.

Description

Technical Field

[0001] The invention relates to the field of semiconductors, and in particular to a method for preparing a TMBS device. Background Art

[0002] The preparation and processing of semiconductor materials are an important part of the modern electronics industry. The development and performance improvement of semiconductor devices are inseparable from advanced semiconductor process technology. TMBS (Trench MOS Barrier Schottky) semiconductor devices are a new type of power device that combines MOS drain structure and Schottky barrier. It has the advantages of low leakage current, fast switching speed and low turn-on voltage drop. It is widely used in power management, electric vehicles, aerospace and other fields.

[0003] TMBS semiconductor process preparation technology is one of the key links in the preparation of TMBS devices. Its quality and stability directly affect the performance and cost of the device. In the process of TMBS semiconductor process preparation, it is necessary to include multiple links such as material growth, device processing, surface treatment, testing and packaging.

[0004] For the structure of traditional TMBS devices, the lower the forward conduction voltage drop and reverse leakage current, the less power loss and the higher the efficiency. However, in the actual process, due to the early breakdown limitation of the large electric field at the corner of the device's trench, the epitaxial layer of the TMBS device is usually not completely exhausted, and the unreasonable setting of the epitaxial layer will also aggravate the substrate diffusion phenomenon. The reverse blocking withstand voltage is almost entirely borne by the epitaxial layer, so how to improve the withstand voltage of the epitaxial layer is extremely important. Summary of the invention

[0005] In view of the problems existing in the prior art, an object of the present invention is to provide a method for preparing a TMBS device.

[0006] The purpose of the present invention is achieved by the following technical solutions:

[0007] A method for preparing a TMBS device comprises the following steps:

[0008] Step 1, prepare the substrate:

[0009] Using single crystal silicon material as substrate material, and then performing surface cleaning treatment to obtain a substrate base;

[0010] Step 2: Prepare the intermediate buffer layer:

[0011] forming an indium nitride buffer layer on the upper surface of the substrate base layer by chemical vapor deposition;

[0012] Step 3: Prepare epitaxial layer:

[0013] Using indium germanium antimonide as the epitaxial layer material, a layer of indium germanium antimonide as the epitaxial layer is grown on the surface of the buffer layer by chemical vapor deposition;

[0014] Step 4: Create grooves:

[0015] A plurality of U-shaped grooves arranged in an array are etched on the upper surface of the epitaxial layer by an etching process, an oxide layer is first formed on the inner surface of the groove, and then polysilicon is filled;

[0016] Step 5, device processing:

[0017] A Schottky barrier is arranged on the upper surface of the epitaxial layer except the trench, and a first metal layer is arranged on the upper surface of the entire epitaxial layer, and a second metal layer is arranged on the lower surface of the substrate base, so as to obtain the desired TMBS device.

[0018] Preferably, in step 1, the purity of the single crystal silicon material is ≥99.9999%.

[0019] Preferably, in step 1, the surface cleaning process includes:

[0020] The substrate material is first immersed in ethanol for ultrasonic cleaning, then immersed in deionized water for ultrasonic cleaning, and then dried by nitrogen blowing to obtain a substrate base layer.

[0021] Preferably, the frequency of ultrasonic cleaning is 20-100 kHz and the temperature is room temperature; ultrasonic cleaning is performed in ethanol for 1-2 min and in deionized water for 20-40 s.

[0022] Preferably, in step 2, the preparation process of the buffer layer includes:

[0023] The substrate base is placed in the reaction chamber of the deposition equipment, nitrogen is introduced as a protective gas, and then a nitrogen source and a gaseous indium source are introduced. The temperature in the reaction chamber is controlled to be 850-1050°C and the pressure is 400-1000mbar. The heat preservation treatment is carried out until the growth thickness of the buffer layer reaches 30-50nm. Then, the introduction of the reaction gas is stopped. After cooling in the furnace, the preparation of the buffer layer is completed.

[0024] Preferably, in step 2, the nitrogen source is ammonia (NH3), the indium source is trimethylindium (In(CH3)3), and the mass ratio of the nitrogen source to the indium source is 1-2:0.8-1.6.

[0025] Preferably, in step 3, the growth process of the epitaxial layer includes:

[0026] First, place the substrate base coated with a buffer layer in the reaction chamber of the deposition equipment. After evacuation, heat it to 350-450°C, introduce hydrogen to keep the pressure in the reaction chamber at 100-200mbar, then introduce gaseous antimony source, indium source and germanium source in proportion, continue to heat it to 500-600°C, and maintain the pressure in the reaction chamber at 300-500mbar. After the growth thickness of the epitaxial layer reaches 2-10μm, shut off the introduction of the reaction gas, and after cooling with the furnace, the preparation of the epitaxial layer is completed.

[0027] Preferably, in step 3, the antimony source, indium source and germanium source are all metal organic compounds, specifically, the antimony source is trimethylantimony (Sb(CH3)3), the indium source is trimethylindium (In(CH3)3), and the germanium source is tetramethylgermanium (Ge(CH3)4).

[0028] Preferably, in step 3, the mass ratio of the antimony source, the indium source and the germanium source is 2.4-4.8:0.9-1.8:0.6-1.2.

[0029] Preferably, in step 4, the thickness of the oxide layer is 60-120 nm.

[0030] Preferably, in step 4, the depth of each groove is 1-3 μm, the width of each groove is 0.3-0.5 μm, and the distance between every two grooves is 0.5-1 μm.

[0031] Preferably, in step 5, the material of the Schottky barrier is metal nitride, including one of tungsten nitride, titanium nitride and aluminum nitride, and has a thickness of 0.4-0.8 μm.

[0032] Preferably, in step 5, during the device processing, the positive electrode is led out through the first metal layer, and the negative electrode is led out through the second metal layer.

[0033] The beneficial effects of the present invention are:

[0034] 1. The substrate material of TMBS devices currently on the market is generally silicon-based. In order to ensure a uniform crystal structure and reduce the influence of grain boundaries and defects in the substrate material, the design of the epitaxial layer is more important. The performance of the epitaxial layer mainly depends on the material itself and the control of the epitaxial growth process. The present invention prepares a new type of epitaxial layer material with a high-purity and low-defect density crystal structure. When applied to a single-crystal silicon substrate material, it can have excellent voltage resistance and on-resistance, thereby improving the electrical performance and reliability of the device.

[0035] 2. The present invention uses an indium nitride buffer layer as an intermediate buffer layer between the substrate base and the epitaxial layer, thereby improving the interface characteristics between different materials, reducing defects, and improving the stability and performance of the overall structure.

[0036] 3. The epitaxial layer used in the present invention is indium germanium antimonide, which not only has lower surface defects than indium antimonide, but also has better breakdown resistance, making TMBS devices have broad application prospects in power electronics, new energy vehicles, photovoltaics and other fields. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is described below through specific examples. It should be understood that the one or more method steps mentioned in the present invention do not exclude the existence of other method steps before and after the combination step or the insertion of other method steps between these explicitly mentioned steps; it should also be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to limit the scope of the present invention. The change or adjustment of the relative relationship thereof shall also be regarded as the scope of the present invention without substantially changing the technical content.

[0038] In order to better understand the above technical scheme, the exemplary embodiments of the present invention are described in more detail below. Although exemplary embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0039] The present invention will be further described below in conjunction with the following examples.

[0040] Example 1

[0041] A method for preparing a TMBS device comprises the following steps:

[0042] Step 1, prepare the substrate:

[0043] A single crystal silicon material with a purity of ≥99.9999% was used as the substrate material (thickness 15 μm), and then the substrate material was first immersed in ethanol for ultrasonic cleaning for 1.5 min, and then immersed in deionized water for ultrasonic cleaning for 30 s, the frequency of ultrasonic cleaning was 60 kHz, the temperature was room temperature, and then dried by nitrogen blowing to obtain a substrate base layer;

[0044] Step 2: Forming an indium nitride buffer layer by chemical vapor deposition (CVD):

[0045] The substrate base is placed in the reaction chamber of the deposition equipment, nitrogen is introduced as a protective gas, and then ammonia (NH3) and trimethyl indium (In(CH3)3) heated to gaseous state are introduced, the mass ratio of ammonia and trimethyl indium is 1.5:1.2, the temperature in the reaction chamber is controlled at 950°C and the pressure is 600mbar, and the heat preservation treatment is carried out until the growth thickness of the buffer layer reaches 40nm, then the introduction of the reaction gas is stopped, and the preparation of the buffer layer is completed after the furnace is cooled;

[0046] Step 3, chemical vapor deposition (CVD) growth of indium germanium antimonide as an epitaxial layer:

[0047] First, place the substrate base coated with the buffer layer in the reaction chamber of the deposition equipment, evacuate the vacuum, heat it to 400°C, introduce hydrogen to keep the pressure in the reaction chamber at 150mbar, and then introduce a mixture of trimethyl antimony (Sb(CH3)3), trimethyl indium (In(CH3)3) and tetramethyl germanium (Ge(CH3)4) heated to gaseous state in proportion, with the mass ratio of trimethyl antimony, trimethyl indium and tetramethyl germanium being 3.6:1.3:0.9. Continue to heat it to 550°C and keep the pressure in the reaction chamber at 400mbar. After the growth thickness of the epitaxial layer reaches 6μm, shut off the introduction of the reaction gas, and after cooling with the furnace, the preparation of the epitaxial layer is completed.

[0048] Step 4: Create grooves:

[0049] A plurality of U-shaped grooves arranged in an array are etched on the upper surface of the epitaxial layer by an etching process. The depth of each groove is 2 μm, the width of each groove is 0.4 μm, and the distance between each two grooves is 0.6 μm. Then, an oxide layer with a thickness of 80 nm is generated on the inner surface of the groove, and then polysilicon is filled.

[0050] Step 5, device processing:

[0051] A Schottky barrier is set on the upper surface of the epitaxial layer except the groove. The material is titanium nitride and the thickness is 0.6μm. A first copper metal layer is set on the upper surface of the entire epitaxial layer. The positive electrode is led out through the first copper metal layer. A second copper metal layer is set on the lower surface of the substrate base layer. The negative electrode is led out through the second copper metal layer, and the desired TMBS device is obtained.

[0052] Example 2

[0053] A method for preparing a TMBS device comprises the following steps:

[0054] Step 1, prepare the substrate:

[0055] A single crystal silicon material with a purity of ≥99.9999% is used as a substrate material, and then the substrate material is first immersed in ethanol for ultrasonic cleaning for 1 minute, and then immersed in deionized water for ultrasonic cleaning for 20 minutes, the frequency of ultrasonic cleaning is 20kHz, the temperature is room temperature, and then it is dried by nitrogen blowing to obtain a substrate base;

[0056] Step 2: Forming an indium nitride buffer layer by chemical vapor deposition (CVD):

[0057] The substrate base is placed in the reaction chamber of the deposition equipment, nitrogen is introduced as a protective gas, and then ammonia (NH3) and trimethyl indium (In(CH3)3) heated to gaseous state are introduced, the mass ratio of ammonia and trimethyl indium is 1:0.8, the temperature in the reaction chamber is controlled to be 850°C, the pressure is 400mbar, and the heat preservation treatment is carried out until the growth thickness of the buffer layer reaches 30nm, then the introduction of the reaction gas is stopped, and the preparation of the buffer layer is completed after the furnace is cooled;

[0058] Step 3, using chemical vapor deposition (CVD) to grow indium germanium antimonide as an epitaxial layer:

[0059] First, place the substrate base coated with the buffer layer in the reaction chamber of the deposition equipment, evacuate the vacuum, heat it to 350°C, introduce hydrogen to keep the pressure in the reaction chamber at 100mbar, and then introduce a mixture of trimethyl antimony (Sb(CH3)3), trimethyl indium (In(CH3)3) and tetramethyl germanium (Ge(CH3)4) heated to gaseous state in proportion, with the mass ratio of trimethyl antimony, trimethyl indium and tetramethyl germanium being 2.4:0.9:0.6. Continue to heat it to 500°C and keep the pressure in the reaction chamber at 300mbar. After the growth thickness of the epitaxial layer reaches 2μm, shut off the introduction of the reaction gas, and after cooling with the furnace, the preparation of the epitaxial layer is completed.

[0060] Step 4: Create grooves:

[0061] A plurality of U-shaped grooves arranged in an array are etched on the upper surface of the epitaxial layer by an etching process. The depth of each groove is 1 μm, the width of each groove is 0.3 μm, and the distance between each two grooves is 0.5 μm. Then, an oxide layer with a thickness of 60 nm is generated on the inner surface of the groove, and then polysilicon is filled.

[0062] Step 5, device processing:

[0063] A Schottky barrier is set on the upper surface of the epitaxial layer except the groove. The material is tungsten nitride with a thickness of 0.4μm. A first metal layer is set on the upper surface of the entire epitaxial layer, and the positive electrode is led out through the first metal layer. A second metal layer is set on the lower surface of the substrate base, and the negative electrode is led out through the second metal layer, so as to obtain the required TMBS device.

[0064] Example 3

[0065] A method for preparing a TMBS device comprises the following steps:

[0066] Step 1, prepare the substrate:

[0067] A single crystal silicon material with a purity of ≥99.9999% is used as a substrate material, and then the substrate material is first immersed in ethanol for ultrasonic cleaning for 2 minutes, and then immersed in deionized water for ultrasonic cleaning for 40 seconds, the frequency of ultrasonic cleaning is 100kHz, the temperature is room temperature, and then it is dried by nitrogen blowing to obtain a substrate base;

[0068] Step 2: Forming an indium nitride buffer layer by chemical vapor deposition (CVD):

[0069] The substrate base is placed in the reaction chamber of the deposition equipment, nitrogen is introduced as a protective gas, and then ammonia (NH3) and trimethyl indium (In(CH3)3) heated to gaseous state are introduced, the mass ratio of ammonia and trimethyl indium is 2:1.6, the temperature in the reaction chamber is controlled at 1050°C and the pressure is 1000mbar, and the heat preservation treatment is carried out until the growth thickness of the buffer layer reaches 50nm, then the introduction of the reaction gas is stopped, and the preparation of the buffer layer is completed after the furnace is cooled;

[0070] Step 3, using chemical vapor deposition (CVD) to grow indium germanium antimonide as an epitaxial layer:

[0071] First, place the substrate base coated with the buffer layer in the reaction chamber of the deposition equipment, evacuate the vacuum, heat it to 450°C, introduce hydrogen to keep the pressure in the reaction chamber at 200mbar, and then introduce a mixture of trimethyl antimony (Sb(CH3)3), trimethyl indium (In(CH3)3) and tetramethyl germanium (Ge(CH3)4) heated to gaseous state in proportion, with the mass ratio of trimethyl antimony, trimethyl indium and tetramethyl germanium being 4.8:1.8:1.2. Continue to heat it to 600°C and keep the pressure in the reaction chamber at 500mbar. After the growth thickness of the epitaxial layer reaches 10μm, shut off the introduction of the reaction gas, and after cooling with the furnace, the preparation of the epitaxial layer is completed.

[0072] Step 4: Create grooves:

[0073] A plurality of U-shaped grooves arranged in an array are etched on the upper surface of the epitaxial layer by an etching process. The depth of each groove is 3 μm, the width of each groove is 0.5 μm, and the distance between each two grooves is 1 μm. Then, an oxide layer with a thickness of 120 nm is generated on the inner surface of the groove, and then polysilicon is filled.

[0074] Step 5, device processing:

[0075] A Schottky barrier is set on the upper surface of the epitaxial layer except the groove. The material is aluminum nitride with a thickness of 0.8μm. A first metal layer is set on the upper surface of the entire epitaxial layer, and the positive electrode is led out through the first metal layer. A second metal layer is set on the lower surface of the substrate base, and the negative electrode is led out through the second metal layer, so as to obtain the desired TMBS device.

[0076] Comparative Example 1

[0077] A method for preparing a TMBS device, which differs from Example 1 only in that the epitaxial layer component of step 3 is indium nitride, that is, no buffer layer is provided, and indium nitride is directly used as the epitaxial layer.

[0078] Step 1, preparing a substrate, the same as in Example 1;

[0079] Step 2, chemical vapor deposition (CVD) growth of indium nitride as an epitaxial layer:

[0080] The substrate base is placed in the reaction chamber of the deposition equipment, nitrogen is introduced as a protective gas, and then ammonia (NH3) and trimethyl indium (In(CH3)3) heated to gaseous state are introduced, the mass ratio of ammonia and trimethyl indium is 1.5:1.2, the temperature in the reaction chamber is controlled at 950°C and the pressure is 600mbar, and the heat preservation treatment is carried out until the growth thickness of the buffer layer reaches 6μm, then the introduction of the reaction gas is stopped, and the epitaxial layer is prepared after cooling with the furnace;

[0081] Step 3, forming a groove, which is the same as in Example 1;

[0082] Step 4, device processing, is the same as in Example 1.

[0083] Comparative Example 2

[0084] A method for preparing a TMBS device, which differs from Example 1 only in that the epitaxial layer composition of step 3 is indium antimonide:

[0085] Step 3, using chemical vapor deposition (CVD) to grow indium germanium antimonide as an epitaxial layer:

[0086] First, place the substrate base coated with a buffer layer in the reaction chamber of the deposition equipment. After evacuation, heat it to 400°C, introduce hydrogen to keep the pressure in the reaction chamber at 150mbar, and then introduce a mixture of trimethylantimony (Sb(CH3)3) and trimethylindium (In(CH3)3) heated to gaseous state in proportion. The mass ratio of trimethylantimony to trimethylindium is 3.6:2.2. Continue to heat it to 550°C and maintain the pressure in the reaction chamber at 400mbar. After the growth thickness of the epitaxial layer reaches 6μm, shut off the introduction of the reaction gas. After cooling with the furnace, the preparation of the epitaxial layer is completed.

[0087] Comparative Example 3

[0088] A method for preparing a TMBS device, which differs from Example 1 only in that the epitaxial layer composition of step 3 is germanium antimonide:

[0089] Step 3, using chemical vapor deposition (CVD) to grow indium germanium antimonide as an epitaxial layer:

[0090] First, place the substrate base coated with a buffer layer in the reaction chamber of the deposition equipment. After evacuation, heat it to 400°C, introduce hydrogen to keep the pressure in the reaction chamber at 150mbar, and then introduce a mixture of trimethylantimony (Sb(CH3)3) and tetramethylgermanium (Ge(CH3)4) heated to gaseous state in proportion. The mass ratio of trimethylantimony to tetramethylgermanium is 3.6:2.2. Continue to heat it to 550°C and maintain the pressure in the reaction chamber at 400mbar. After the growth thickness of the epitaxial layer reaches 6μm, shut off the introduction of the reaction gas. After cooling with the furnace, the preparation of the epitaxial layer is completed.

[0091] The performance of the TMBS devices prepared in Example 1 and Comparative Examples 1-3 were compared. The following results were obtained by testing at 25°C / 55RH%, where the test current density at the forward conduction voltage drop was 180A·cm -2 Under the condition of , the test results of other parameters are shown in Table 1:

[0092] Table 1 Performance of different TMBS devices

[0093]

[0094] From the test results in Table 1, it can be seen that the test current density at the forward voltage drop is 180A·cm -2 Under the conditions, Example 1 of the present invention has a higher breakdown voltage, a smaller forward voltage drop, and a lower leakage current density, indicating that it has excellent voltage resistance and on-resistance value, and can improve the electrical performance and reliability of the device.

[0095] 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 representation of the above terms should not be understood as necessarily being directed 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 different embodiments or examples described in this specification.

[0096] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for preparing a TMBS device, characterized in that: The following steps are involved: Step 1, prepare the substrate: Using single crystal silicon material as substrate material, and then performing surface cleaning treatment to obtain a substrate base; Step 2: Prepare the intermediate buffer layer: forming an indium nitride buffer layer on the upper surface of the substrate base layer by chemical vapor deposition; Step 3: Prepare epitaxial layer: Using indium germanium antimonide as the epitaxial layer material, a layer of indium germanium antimonide as the epitaxial layer is grown on the surface of the buffer layer by chemical vapor deposition; Step 4: Create grooves: A plurality of U-shaped grooves arranged in an array are etched on the upper surface of the epitaxial layer by an etching process, an oxide layer is first formed on the inner surface of the groove, and then polysilicon is filled; Step 5, device processing: A Schottky barrier is arranged on the upper surface of the epitaxial layer except the groove, and a first metal layer is arranged on the upper surface of the entire epitaxial layer, and a second metal layer is arranged on the lower surface of the substrate base, so as to obtain the desired TMBS device; In step 3, the growth process of the epitaxial layer includes: First, place the substrate base coated with the buffer layer in the reaction chamber of the deposition equipment, evacuate the vacuum, heat it to 350-450°C, introduce hydrogen to keep the pressure in the reaction chamber at 100-200mbar, then introduce gaseous antimony source, indium source and germanium source in proportion, continue to heat it to 500-600°C, and keep the pressure in the reaction chamber at 300-500mbar. After the growth thickness of the epitaxial layer reaches 2-10μm, stop introducing the reaction gas, and cool it with the furnace to complete the preparation of the epitaxial layer. In the step 3, the mass ratio of the antimony source, the indium source and the germanium source is 2.4-4.8:0.9-1.8:0.6-1.

2.

2. The method for preparing a TMBS device according to claim 1, characterized in that: In step 1, the surface cleaning process includes: The substrate material is first immersed in ethanol for ultrasonic cleaning, then immersed in deionized water for ultrasonic cleaning, and then dried by nitrogen blowing to obtain a substrate base layer; the frequency of ultrasonic cleaning is 20-100kHz, and the temperature is room temperature; ultrasonic cleaning is performed in ethanol for 1-2 minutes, and ultrasonic cleaning is performed in deionized water for 20-40 seconds.

3. The method for preparing a TMBS device according to claim 1, characterized in that: In step 2, the preparation process of the buffer layer includes: The substrate base is placed in the reaction chamber of the deposition equipment, nitrogen is introduced as a protective gas, and then a nitrogen source and a gaseous indium source are introduced. The temperature in the reaction chamber is controlled to be 850-1050°C and the pressure is 400-1000mbar. The heat preservation treatment is carried out until the growth thickness of the buffer layer reaches 30-50nm. Then, the introduction of the reaction gas is stopped. After cooling in the furnace, the preparation of the buffer layer is completed.

4. The method for preparing a TMBS device according to claim 3, characterized in that: In the step 2, the nitrogen source is ammonia, the indium source is trimethylindium, and the mass ratio of the nitrogen source to the indium source is 1-2:0.8-1.

6.

5. The method for preparing a TMBS device according to claim 1, characterized in that: In step 3, the antimony source is trimethyl antimony, the indium source is trimethyl indium, and the germanium source is tetramethyl germanium.

6. The method for preparing a TMBS device according to claim 1, characterized in that: In step 4, the thickness of the oxide layer is 60-120 nm; the depth of each groove is 1-3 μm, the width of each groove is 0.3-0.5 μm, and the distance between every two grooves is 0.5-1 μm.

7. The method for preparing a TMBS device according to claim 1, characterized in that: In the step 5, the material of the Schottky barrier is metal nitride, including one of tungsten nitride, titanium nitride and aluminum nitride, and the thickness is 0.4-0.8 μm.

8. The method for preparing a TMBS device according to claim 1, characterized in that: In step 5, during the device processing, the positive electrode is led out through the first metal layer, and the negative electrode is led out through the second metal layer.

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