Radiation tolerant diamond schottky diode and method of making same

Abstract

An irradiation-resistant diamond Schottky diode and its fabrication method are disclosed. The purpose of this invention is to solve the problem of poor radiation resistance stability in Schottky diodes. In this irradiation-resistant diamond Schottky diode, p-type diodes are epitaxially grown on an intrinsic diamond substrate. + Diamond epitaxial layer, in p + An ohmic electrode is deposited in a portion of the upper surface of the diamond epitaxial layer, at p + p-type epitaxial growth is performed on the region of the diamond epitaxial layer where no ohmic electrode is deposited. ‑ Type II diamond drift layer, in p ‑ Easily oxidizable metal electrodes are deposited on a diamond drift layer, serving as Schottky electrodes. These electrodes are then terminated with oxygen. ‑ A metal oxide layer is formed between the drift layers of the diamond. This invention utilizes a low work function, easily oxidizable metal as a Schottky electrode. The low work function, easily oxidizable metal passivates the oxygen terminals on the diamond surface. The oxide layer formed on the diamond surface makes the oxygen terminals less susceptible to radiation-induced reconstruction, resulting in stronger radiation resistance.

Description

Technical Field

[0001] This invention belongs to the field of wide bandgap semiconductor power device fabrication technology, specifically relating to a radiation-resistant diamond Schottky diode using a low work function, easily oxidized metal as a Schottky electrode and its fabrication method. Background Technology

[0002] Diamond semiconductors, due to their excellent material properties, have broad application prospects in power devices requiring high breakdown voltage, low on-resistance, and low switching losses. Diamond also possesses excellent radiation resistance; the carbon atoms within diamond are arranged in an sp... 3 Hybridization forms a stable tetrahedral spatial network structure. The high covalent bond energy between carbon atoms in diamond, along with strong lattice bonding and a higher displacement threshold energy, makes it difficult for high-energy particles to alter the lattice positions, thus minimizing the formation of permanent irradiation defects such as vacancies and interstitial atoms. Simultaneously, the low atomic number of carbon results in weak energy scattering and minimal secondary radiation when bombarded by high-energy rays and particles, significantly reducing cascade damage and non-ionizing damage. Diamond's ultra-wide bandgap of 5.47 eV and extremely low intrinsic carrier concentration at room temperature make it difficult for irradiation to generate a large number of electron-hole pairs, resulting in minimal dark current. Furthermore, the energy levels of irradiation-derived defects are mostly located deep within the bandgap, making it difficult to interfere with carrier transport, effectively avoiding problems such as device leakage and failure. In addition, diamond's thermal conductivity far exceeds that of semiconductor materials such as silicon, allowing for rapid heat dissipation to suppress thermal damage. The material also possesses excellent annealing self-healing properties, capable of repairing most simple irradiation defects at low temperatures, greatly increasing the damage tolerance limit under high-energy irradiation environments and adapting to extreme radiation conditions.

[0003] Diamond epitaxial layers are prone to native defects such as dislocations and vacancies, which transform into stable deep-level traps under irradiation, exacerbating carrier decay and parameter drift. The uniformity of p-type boron doping concentration and thickness is difficult to control, and n-type doping technology is not yet mature enough to form an effective PN junction, limiting the device's voltage withstand capability and radiation resistance stability. Diamond has a high surface state density and a significant Fermi level pinning effect, resulting in uneven Schottky barrier height and poor controllability. High-energy particle irradiation introduces displacement defects such as vacancies and interstitial atoms into the drift region, acting as recombination centers and reducing carrier concentration. Simultaneously, the electric field concentration at the electrode edges increases the risk of local breakdown. Existing field plates, passivation layers, and other terminal structures are complex and prone to introducing additional damage, making it difficult to simultaneously meet the requirements of radiation resistance and high voltage withstand capability. Furthermore, the fabrication of highly doped diamond ohmic contacts is difficult, resulting in high contact resistance and easy degradation after irradiation. Under the combined effects of high temperature and irradiation, electromigration and thermal expansion mismatch easily occur at the metal electrode-diamond interface, leading to contact failure and device performance degradation. Summary of the Invention

[0004] The purpose of this invention is to solve the problem of poor radiation resistance stability of Schottky diodes, and to provide a radiation-resistant diamond Schottky diode and its preparation method.

[0005] The radiation-resistant diamond Schottky diode of this invention includes a diamond substrate, p + Diamond epitaxial layer, p - A diamond drift layer, an ohmic electrode, an easily oxidized metal electrode, and a metal oxide layer are epitaxially grown on a diamond substrate. + Diamond epitaxial layer, in p + An ohmic electrode is deposited in a portion of the upper surface of the diamond epitaxial layer, at p + Epitaxial growth of p-type electrodes occurs in the region on the surface of the diamond epitaxial layer where no ohmic electrode is deposited. - Type II diamond drift layer, p - The diamond drift layer has oxygen terminals, in p - Easily oxidizable metal electrodes are deposited on a diamond drift layer, serving as Schottky electrodes. These electrodes interact with oxygen-terminated p-type... - A metal oxide layer is formed between the drift layers of the diamond.

[0006] This invention relates to a radiation-resistant diamond Schottky diode, comprising a diamond substrate, an epitaxial layer, and electrodes. The radiation-resistant diamond Schottky diode is fabricated by utilizing a low work function, easily oxidizable metal as the diamond Schottky electrode metal. The low work function, easily oxidizable metal passivates the oxygen terminals on the diamond surface. The oxide layer formed on the diamond surface makes the oxygen terminals less susceptible to radiation-induced reconstruction, thus exhibiting stronger radiation resistance.

[0007] The method for preparing the radiation-resistant diamond Schottky diode of the present invention is carried out according to the following steps:

[0008] Step 1: Substrate Pretreatment

[0009] The diamond substrate was placed in a mixed acid solution and heated at high temperature, and then ultrasonically cleaned to obtain a diamond substrate with oxygen terminals.

[0010] Step 2: Epitaxial growth of the heavily boron-doped layer:

[0011] Using a solid boron source, heavily boron-doped p-type diamond was epitaxially grown on an oxygen-terminated diamond substrate using microwave plasma chemical vapor deposition. + Diamond epitaxial layer, after cleaning, yields p + Diamond epitaxial layer;

[0012] Step 3: Deposition of the ohmic electrode:

[0013] Using ultraviolet lithography on p + An ohmic electrode region is formed on the upper surface of the diamond epitaxial layer, and an ohmic electrode is obtained by magnetron sputtering in the ohmic electrode region.

[0014] Step 4: Epitaxial growth of the lightly doped layer:

[0015] Microwave plasma chemical vapor deposition process was used in p + Lightly boron-doped p-type diamond epitaxial growth is performed on the upper surface of the diamond epitaxial layer. - Diamond epitaxial layer, after oxidation treatment, yields p-type diamond with oxygen terminals. - Type II diamond drift layer;

[0016] Step 5: Schottky electrode fabrication:

[0017] Using ultraviolet lithography to apply oxygen-terminated p - An easily oxidizable metal electrode region is formed on the surface of the diamond drift layer. An easily oxidizable metal electrode is deposited in the easily oxidizable metal electrode region using a magnetron sputtering process to obtain a radiation-resistant diamond Schottky diode.

[0018] Diamond Schottky diodes use p-type boron-doped diamond as their core, consisting of a heavily doped diamond ohmic contact layer and a lightly doped breakdown drift layer. When the metal contacts the p-type diamond, the Fermi level difference creates a Schottky barrier and a depletion layer at the interface to block holes. When forward biased, the metal Schottky electrode is connected to the positive terminal and the ohmic electrode is connected to the negative terminal. The applied voltage cancels the built-in electric field and lowers the barrier height, allowing a large number of majority carrier holes in the drift layer to cross the barrier and flow to the metal to form a conduction current. When reverse biased, the metal is connected to the negative terminal, and the external electric field further raises the barrier, causing the depletion layer to widen significantly into the drift layer, resulting in a low leakage current state when the device is off.

[0019] When inert metals are used as Schottky electrodes, their insufficient reaction with oxygen-terminated diamond fails to form an oxide interlayer, leading to oxygen desorption under extreme environments such as high temperature, high pressure, and high radiation, thus degrading the Schottky contact characteristics. In contrast, Schottky diodes made from easily oxidized metals with low work function readily form a higher Schottky barrier with p-type diamond, and these metals easily form oxide passivation at the oxygen-terminated diamond interface, resulting in superior radiation resistance.

[0020] The method for preparing the radiation-resistant diamond Schottky diode of the present invention has the following beneficial effects:

[0021] Schottky electrodes are fabricated using easily oxidizable metal materials. The spontaneous oxidation of the metal surface forms an oxide buffer layer, effectively mitigating the Fermi level pinning effect on the diamond surface. By precisely controlling the interface barrier and reducing the overall work function of the electrode, the forward conduction voltage drop of the device is significantly reduced, thereby decreasing conduction losses and optimizing rectification characteristics. This solves the problems of uncontrollable potential barriers and high energy consumption associated with traditional noble metal electrodes. Simultaneously, the dense oxide layer formed on the electrode surface isolates the metal from the diamond substrate, passivating native defects and etching damage on the diamond surface, suppressing inter-atomic diffusion at the interface under high-energy particle irradiation, and alleviating the problem of thermal expansion coefficient mismatch between materials. This avoids electrode detachment and interface degradation under high-temperature, strong irradiation coupling conditions, significantly improving the device's radiation resistance and lifespan. Furthermore, easily oxidizable metal raw materials are inexpensive, and the electrodes can be prepared at room temperature, eliminating complex processes such as high-temperature annealing and ion modification, simplifying the production process and lowering the technological threshold.

[0022] The diamond Schottky diode of this invention combines the advantages of high radiation resistance and easy fabrication, effectively solving the bottleneck of diamond diode engineering applications and making it suitable for extreme radiation operation scenarios such as aerospace exploration and nuclear reactors. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating the fabrication process of the radiation-resistant diamond Schottky diode of this invention.

[0024] Figure 2 This is a schematic cross-sectional view of the diamond Schottky diode structure in the embodiment, with the inert metal electrode 5 used for comparison;

[0025] Figure 3 The diagram shows the device performance of the diamond Schottky diode before and after irradiation in the embodiment.

[0026] Figure 4 This is a diagram showing the deep level defect test results of the diamond Schottky diode after irradiation in the embodiment.

[0027] Figure 5 This is a test image of the diamond Schottky diode after irradiation and its recovery time at zero bias in the embodiment.

[0028] Figure 6 This is a test diagram of the reverse bias recovery time effect of the diamond Schottky diode after irradiation in the embodiment;

[0029] Figure reference numerals: 1 - diamond substrate, 2 - p + Diamond epitaxial layer, 3-p - Type 1 diamond drift layer, 4-ohmic electrode, 5-inert metal electrode, 6-easily oxidizable metal electrode, 7-metal oxide layer. Detailed Implementation

[0030] Specific Implementation Method 1: This implementation method includes a radiation-resistant diamond Schottky diode comprising a diamond substrate 1, p... + Diamond epitaxial layer 2, p - A diamond drift layer 3, an ohmic electrode 4, an easily oxidized metal electrode 6, and a metal oxide layer 7 are epitaxially grown on an intrinsic diamond substrate 1. + Diamond epitaxial layer 2, in p + An ohmic electrode 4 is deposited in a portion of the upper surface of the diamond epitaxial layer 2, in p + p is epitaxially grown in the region on the upper surface of the diamond epitaxial layer 2 where the ohmic electrode 4 is not deposited. - Type 3 diamond drift layer, p - The diamond drift layer 3 has oxygen terminals, in p - An easily oxidizable metal electrode 6 is deposited on a diamond drift layer 3. The easily oxidizable metal electrode 6 serves as a Schottky electrode. The easily oxidizable metal electrode 6 interacts with a p-type electrode with oxygen termination. - A metal oxide layer 7 is formed between the diamond drift layers 3.

[0031] This embodiment employs a microwave plasma chemical vapor deposition system for the epitaxial growth of diamond, utilizing a low work function, easily oxidizable metal as the diamond Schottky electrode metal. The low work function and easy oxidation form oxides on the diamond surface, passivating the oxygen terminals and giving the Schottky diode enhanced radiation resistance.

[0032] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that p + The thickness of the diamond epitaxial layer 2 is 1~10µm.

[0033] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that p - The thickness of the diamond drift layer 3 is 0.5~5µm.

[0034] Specific Implementation Method Four: This implementation method differs from one of the specific implementation methods one to three in that the material of the easily oxidized metal electrode 6 is yttrium (Y), scandium (Sc), aluminum (Al), or zirconium (Zr).

[0035] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One through Four in that p + Diamond epitaxial layer 2 and p - The doping element in the diamond drift layer 3 is boron.

[0036] Specific Implementation Method Six: This implementation method differs from one of the specific implementation methods one to five in that the thickness of the easily oxidized metal electrode 6 is 20~100nm.

[0037] Specific Implementation Method Seven: The method for preparing the radiation-resistant diamond Schottky diode in this implementation method is carried out according to the following steps:

[0038] Step 1: Substrate Pretreatment

[0039] Diamond substrate 1 was placed in a mixed acid solution and heated at high temperature. After ultrasonic cleaning, a diamond substrate with oxygen terminals was obtained.

[0040] Step 2: Epitaxial growth of the heavily boron-doped layer:

[0041] Using a solid boron source, heavily boron-doped p-type diamond was epitaxially grown on an oxygen-terminated diamond substrate using microwave plasma chemical vapor deposition. + Diamond epitaxial layer, after cleaning, yields p + Diamond epitaxial layer 2;

[0042] Step 3: Deposition of the ohmic electrode:

[0043] Using ultraviolet lithography on p + An ohmic electrode region is formed on the upper surface of the diamond epitaxial layer 2, and an ohmic electrode 4 is obtained by magnetron sputtering in the ohmic electrode region.

[0044] Step 4: Epitaxial growth of the lightly doped layer:

[0045] Microwave plasma chemical vapor deposition process was used in p + Lightly boron-doped p-type diamond is epitaxially grown on the upper surface of diamond epitaxial layer 2. - Diamond epitaxial layer, after oxidation treatment, yields p-type diamond with oxygen terminals. - Type 3 diamond drift layer;

[0046] Step 5: Schottky electrode fabrication:

[0047] Using ultraviolet lithography to apply oxygen-terminated p - An easily oxidizable metal electrode region is formed on the surface of the diamond drift layer 3. An easily oxidizable metal electrode 6 is deposited in the easily oxidizable metal electrode region using a magnetron sputtering process to obtain a radiation-resistant diamond Schottky diode.

[0048] This implementation method p + Diamond epitaxial layer 2 and p - The growth process of the diamond drift layer 3 is as follows: microwave power is 1000W~3000W, substrate temperature is 700~1000℃, gas pressure is 5~12kPa, and methane concentration is 1%~5%.

[0049] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that the mixed acid solution in step one is a mixture of concentrated sulfuric acid with a mass concentration of 98% and concentrated nitric acid with a mass concentration of 67% in a volume ratio of 3:1.

[0050] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that the high-temperature heating treatment in step one is performed at a temperature of 230~350℃ for 2.0~2.5 hours.

[0051] Specific Implementation Method 10: This implementation method differs from Specific Implementation Methods 1 to 9 in that the oxidation treatment in step 4 is performed using oxygen plasma treatment for 10 to 120 minutes.

[0052] Specific Implementation Method Eleven: This implementation method differs from Specific Implementation Methods One through Ten in that p + The boron doping concentration in diamond epitaxial layer 2 is 10. 19 ~10 21 cm -3 p - The boron doping concentration in the diamond drift layer 3 is 10. 15 ~10 16 cm -3 .

[0053] Example 1: The fabrication method of the radiation-resistant diamond Schottky diode in this example is implemented according to the following steps:

[0054] Step 1: Substrate Pretreatment

[0055] Diamond substrate 1 was placed in a mixed acid solution, which was a mixture of concentrated sulfuric acid with a mass concentration of 98% and concentrated nitric acid with a mass concentration of 67% in a volume ratio of 3:1. The mixture was treated at 350 °C for 2 h, and then ultrasonically cleaned in deionized water and anhydrous ethanol for 10 min each to obtain a diamond substrate with oxygen terminals.

[0056] Step 2: Epitaxial growth of the heavily boron-doped layer:

[0057] Using a solid boron source (pure boron), heavy boron-doped p-type diamond was epitaxially grown on an oxygen-terminated diamond substrate using microwave plasma chemical vapor deposition. + A diamond epitaxial layer was prepared by controlling the microwave power at 2950 W, the diamond substrate temperature at 890 ℃, the chamber pressure at 6.8 kPa, the H2 flow rate at 388 sccm, and the CH4 flow rate at 12 sccm. After further treatment using the cleaning process described in step one, a doping concentration of 10 was obtained. 20 cm -3 p + Diamond epitaxial layer 2;

[0058] Step 3: Deposition of the ohmic electrode:

[0059] Using ultraviolet lithography on p + AZ5214 positive photoresist was spin-coated onto the upper surface of the diamond epitaxial layer 2. After pre-baking at 90°C for 90 s, ultraviolet lithography was performed to pattern the layer. Titanium (Ti), platinum (Pt), and gold (Au) were sequentially sputtered into the ohmic electrode region using a magnetron sputtering process to form a stacked metal layer with thicknesses of Ti:Pt:Au = 20:20:40 nm, resulting in the ohmic electrode 4.

[0060] Step 4: Epitaxial growth of the lightly doped layer:

[0061] Microwave plasma chemical vapor deposition process was used in p + Lightly boron-doped p-type diamond is epitaxially grown on the upper surface of diamond epitaxial layer 2. - Diamond epitaxial layer, with controlled epitaxial growth parameters: microwave power 2050 W, hydrogen flow rate 196 sccm, methane flow rate 4 sccm, growth temperature 850 ℃, gas pressure 67 Torr, deposition time 30 min, followed by oxygen plasma oxidation treatment for 1 h to obtain a doping concentration of 10. 16 cm -3 p with oxygen terminal - Type 3 diamond drift layer;

[0062] Step 5: Schottky electrode fabrication:

[0063] Using ultraviolet lithography to apply oxygen-terminated p - An easily oxidizable metal electrode region is formed on the surface of the diamond drift layer 3. A 60 nm thick yttrium (Y) electrode is deposited in the easily oxidizable metal electrode region using an electron beam evaporation process to serve as the easily oxidizable metal electrode 6, thereby obtaining a radiation-resistant diamond Schottky diode.

[0064] Comparative Example: This example differs from Example 1 in that step five uses an electron beam evaporation process to deposit a 60 nm thick Au (Au) electrode, followed by a lift-off process to form a gold (Au) Schottky electrode, thus completing the fabrication of the diamond Schottky diode.

[0065] The prepared Schottky diodes were characterized before and after irradiation to obtain their breakdown characteristics. Figure 3 The reverse characteristic test results are for gold (Au) Schottky diodes and yttrium (Y) Schottky diodes. Figure 4 (ad) shows the deep level transient spectrum (DLTS) test results, which investigate the deep level defect types and energy level positions of different metal diodes; Figure 5 and Figure 6The on-the-fly test results with applied pulse voltage under zero bias and reverse bias are used to study the effect of deep level defects on the electrical performance of diodes.

[0066] As shown in the test results above, the breakdown voltage of the gold (Au) diamond Schottky diode decreased from 140V to 83V, a performance reduction of 40.7%, while the breakdown voltage of the easily oxidized metal yttrium (Y) Schottky diode decreased from 152V to 138V, a performance reduction of only 9.2%, and its radiation resistance improved by nearly 4 times. Deep-level transient tests revealed that the gold (Au) Schottky diode has two main deep-level traps: a hole trap (H1) in the test range of 157 to 174 K, and an electron trap (E1) in the temperature range of 296 to 306 K. The deep-level electron traps significantly affect the forward conduction characteristics of the diamond Schottky diode. In contrast, the deep-level traps in the yttrium (Y) Schottky diode are all hole traps (H1, H2, and H3). The hole traps do not increase the space charge density after capturing holes, and the deep-level hole traps are filled with holes. During the recovery time, the holes gradually escape the traps and return to the valence band. However, the emission time of holes is relatively long. As the recovery time increases, the concentration of free holes in the valence band gradually increases, and the forward current increases with the extension of the recovery time. Therefore, the yttrium (Y) Schottky diode maintains almost the same breakdown voltage after irradiation compared to before irradiation. The yttrium metal electrode diamond Schottky diode has a significantly improved radiation resistance compared to the gold (Au) Schottky diode.

[0067] Deep-level transient spectrum analysis proved that the deep-level electron traps in the gold electrode Schottky diode are the main cause of the degradation of the reverse breakdown voltage of the device. In the yttrium diamond Schottky diode, the deep-level traps are hole traps, so the breakdown voltage remains almost unchanged after irradiation.

[0068] In summary, this invention proposes a radiation-resistant diamond Schottky diode and its fabrication method. Easily oxidizable metals such as yttrium can form a denser oxide layer with oxygen terminals on the diamond surface, and low work function metals readily form a higher Schottky barrier with p-type diamond. The oxygen terminals are less susceptible to reconstruction under radiation, thus exhibiting stronger radiation resistance.

[0069] Although the present invention has been described in detail through the above preferred embodiments, the above description should not be considered as a limitation of the present invention. Other solutions based on the same principle are also within the protection scope of the present invention. Modifications and substitutions of the present invention will be obvious to those skilled in the art after reading the above content. Therefore, the protection scope of the present invention should be defined by the appended claims.

Claims

1. A radiation-resistant diamond Schottky diode, characterized in that... This radiation-resistant diamond Schottky diode includes a diamond substrate (1), p + Diamond epitaxial layer (2), p - A diamond drift layer (3), an ohmic electrode (4), an easily oxidized metal electrode (6), and a metal oxide layer (7) are epitaxially grown on a diamond substrate (1). + Diamond epitaxial layer (2), in p + An ohmic electrode (4) is deposited in a portion of the upper surface of the diamond epitaxial layer (2), in p + Epitaxial growth of p in the region on the upper surface of the diamond epitaxial layer (2) where the ohmic electrode (4) is not deposited - Type 3 diamond drift layer (3), p - The diamond drift layer (3) has oxygen terminals, and in p - An easily oxidizable metal electrode (6) is deposited on a diamond drift layer (3). The easily oxidizable metal electrode (6) serves as a Schottky electrode. The easily oxidizable metal electrode (6) interacts with a p-type electrode with oxygen terminals. - A metal oxide layer (7) is formed between the diamond drift layers (3).

2. The radiation-resistant diamond Schottky diode according to claim 1, characterized in that... p + The thickness of the diamond epitaxial layer (2) is 1~10µm.

3. The radiation-resistant diamond Schottky diode according to claim 1, characterized in that... p - The thickness of the diamond drift layer (3) is 0.5~5µm.

4. The radiation-resistant diamond Schottky diode according to claim 1, characterized in that... The material of the easily oxidized metal electrode (6) is yttrium, scandium, aluminum or zirconium.

5. The radiation-resistant diamond Schottky diode according to claim 1, characterized in that... p + Diamond epitaxial layer (2) and p - The doping element in the diamond drift layer (3) is boron.

6. The radiation-resistant diamond Schottky diode according to claim 1, characterized in that... The thickness of the easily oxidized metal electrode (6) is 20~100nm.

7. The method for preparing a radiation-resistant diamond Schottky diode as described in claim 1, characterized in that... The method for fabricating the radiation-resistant diamond Schottky diode is carried out according to the following steps: Step 1: Substrate Pretreatment The diamond substrate (1) was placed in a mixed acid solution and heated at high temperature. After ultrasonic cleaning, a diamond substrate with oxygen terminals was obtained. Step 2: Epitaxial growth of the heavily boron-doped layer: Using a solid boron source, heavily boron-doped p-type diamond was epitaxially grown on an oxygen-terminated diamond substrate using microwave plasma chemical vapor deposition. + Diamond epitaxial layer, after cleaning, yields p + Diamond epitaxial layer (2); Step 3: Deposition of the ohmic electrode: Using ultraviolet lithography on p + An ohmic electrode region is formed on the upper surface of the diamond epitaxial layer (2), and an ohmic electrode (4) is obtained by magnetron sputtering in the ohmic electrode region. Step 4: Epitaxial growth of the lightly doped layer: Microwave plasma chemical vapor deposition was used in p + Lightly boron-doped p-type diamond epitaxial layer (2) is epitaxially grown on its upper surface. - Diamond epitaxial layer, after oxidation treatment, yields p-type diamond with oxygen terminals. - Type II diamond drift layer (3); Step 5: Schottky electrode fabrication: Using ultraviolet lithography to apply oxygen-terminated p - An easily oxidizable metal electrode region is formed on the surface of the diamond drift layer (3). An easily oxidizable metal electrode (6) is deposited in the easily oxidizable metal electrode region by magnetron sputtering process to obtain a radiation-resistant diamond Schottky diode.

8. The method for preparing a radiation-resistant diamond Schottky diode according to claim 7, characterized in that... The mixed acid solution in step one is a mixture of concentrated sulfuric acid with a mass concentration of 98% and concentrated nitric acid with a mass concentration of 67% in a volume ratio of 3:

1.

9. The method for preparing a radiation-resistant diamond Schottky diode according to claim 7, characterized in that... The oxidation treatment described in step four involves oxygen plasma treatment for 10 to 120 minutes.

10. The method for preparing a radiation-resistant diamond Schottky diode according to claim 7, characterized in that... p + The boron doping concentration in the diamond epitaxial layer (2) is 10. 19 ~10 21 cm -3 p - The boron doping concentration in the diamond drift layer (3) is 10. 15 ~10 16 cm -3 .

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