Preparation method of photoelectric detector with ultrafast cooling structure

Abstract

The invention aims to provide a preparation method of a photoelectric detector with an ultrafast cooling structure, and belongs to the field of heat dissipation of optoelectronic devices. The structure of the photoelectric detector sequentially comprises two layers of diamond-based liquid flowing channels which are perpendicular to each other, silicon, vertical graphene and source electrodes and drain electrodes on the two sides from bottom to top, specifically, a molybdenum wire is placed on a silicon substrate with a micro-channel to grow a diamond film, and after the diamond film is processed and processed into a new micro-channel, the molybdenum wire is placed again to deposit diamond; the method comprises the following steps: preparing two layers of diamond-based liquid flowing channels which are perpendicular to each other to obtain an ultrafast cooling structure, depositing a vertical graphene film on the flat surface of a silicon wafer with the ultrafast cooling structure, and finally plating a metal electrode on the vertical graphene and patterning. In combination with the excellent heat conduction characteristic of diamond, an ultrafast cooling structure is constructed through two layers of diamond-based liquid flowing channels which are perpendicular to each other, so that efficient heat dissipation is realized to ensure the working stability and the service life of the photoelectric detector.

Description

Technical Field

[0001] The invention belongs to the field of heat dissipation of optoelectronic devices, and in particular relates to a method for preparing a photoelectric detector with an ultrafast cooling structure. Background Art

[0002] As the trend of high performance, miniaturization and integration accelerates, the high heat generated by photodetectors during operation needs to be dissipated in a timely manner, otherwise it is very easy to cause problems such as damage to its internal structure, deformation of materials and functional failure. In order to ensure stable service and sufficient service life, good heat dissipation design has become the key to enhancing the reliability, responsiveness and integration of photodetectors.

[0003] Patent CN107731903A discloses a heat dissipation structure for an integrated photodetector, which is used to solve the problem of high temperature of multi-component circuit boards caused by long-term use of photodetectors. However, this structure uses wind power to cool the heat on the surface of the tower heat sink, which is a traditional cooling method and its thermal conductivity efficiency needs to be improved. Microchannel cooling increases the contact area between the radiator and the cooling medium per unit volume to obtain a very high surface heat transfer coefficient. Compared with it, it has obvious advantages such as compact structure, high heat exchange efficiency and small heat transfer temperature difference. Diamond material has excellent thermal conductivity (~2000W / m K), and its physical and chemical properties are stable and not easily corroded by the environment, making it an excellent material for making microchannels. Therefore, for photodetectors under the above heat dissipation requirements, diamond can be used as a heat dissipation substrate, especially for microchannel structures with added flowing cooling media, which can achieve ultra-fast heat dissipation, thereby effectively suppressing the temperature increase of the device during operation and ensuring its reliability and life.

[0004] Due to the low electron mobility (1350 cm 2 Intrinsic properties such as low bandgap (V / v·s) and indirect bandgap structure are increasingly showing their limitations in the field of optoelectronic devices. In addition, the operating wavelength of pure silicon-based photodetectors is also limited to visible light and part of the infrared band, which brings new challenges to the development of traditional photodetectors. Since the successful preparation of graphene, its semi-metallic zero bandgap, ultra-high mobility (>10000 cm 2 / v·s), and its compatibility with traditional materials such as silicon has been demonstrated in photoelectric detection applications. Among them, vertical graphene has extremely high light absorption rate due to its unique flake branching structure. At the same time, since vertical graphene can be grown directly on any substrate without a catalyst, it has more advantages in the application of photodetectors than planar graphene, which usually requires metal catalysis to prepare and transfer. Summary of the invention

[0005] In order to solve the heat dissipation problem of device operation and promote the application and development of silicon-based photodetectors, and give full play to the excellent characteristics of diamond and vertical graphene, the present invention provides a method for preparing a photodetector with an ultrafast cooling structure, specifically, placing a molybdenum wire on a silicon substrate with microgrooves to grow a diamond film, processing the diamond film with new microgrooves and then placing the molybdenum wire again to deposit diamond, preparing two layers of mutually perpendicular diamond-based liquid flow channels to obtain an ultrafast cooling structure, and then depositing a vertical graphene film on the flat surface of the silicon wafer with the ultrafast cooling structure, and finally plating a metal electrode on the vertical graphene and patterning it to prepare a photodetector with an ultrafast cooling structure.

[0006] The purpose of the present invention is to provide a method for preparing a photodetector with an ultrafast cooling structure. Combining the excellent thermal conductivity of diamond, an ultrafast cooling structure is constructed through two layers of mutually perpendicular liquid flow channels, thereby achieving efficient heat dissipation to ensure the working stability and service life of the photodetector.

[0007] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are provided:

[0008] The present invention provides a method for preparing a photoelectric detector with an ultrafast cooling structure, comprising the following steps:

[0009] Step 1, silicon substrate pretreatment:

[0010] Perform micro-groove processing on the surface of the polished silicon wafer and ultrasonically clean the processed silicon wafer;

[0011] Step 2, place the molybdenum wire:

[0012] Molybdenum wires of consistent size are selected and placed on the micro-grooves of the silicon wafer;

[0013] Step 3, diamond preparation, micro-groove processing and acid treatment:

[0014] The silicon wafer with the molybdenum wire filled in the micro-grooves is used as a substrate for diamond growth, and is placed in a deposition device to prepare diamonds until the silicon wafer and the molybdenum wire surface are fully covered, and then diamonds of a certain thickness are grown, and the deposited diamonds are ground and polished, and then the micro-grooves are processed by laser in the direction perpendicular to the molybdenum wire and acid treated;

[0015] Step 4, place new molybdenum wire:

[0016] Use molybdenum wires of consistent size to place on the micro grooves of the diamond;

[0017] Step 5, preparation and processing of the second diamond film:

[0018] The diamond filled with molybdenum wire is placed in a deposition device to prepare a second layer of diamond film. After the diamond grows to fully cover the diamond substrate and the surface of the molybdenum wire, it grows to a certain thickness, and the grown diamond is ground and polished;

[0019] Step 6, remove the molybdenum wire:

[0020] The molybdenum wire between diamonds was treated with acid to obtain two layers of mutually perpendicular liquid flow channels;

[0021] Step 7, preparation of vertical graphene:

[0022] A vertical graphene film is prepared on a flat surface of a silicon substrate having a liquid flow channel;

[0023] Step 8, fabrication of photodetector:

[0024] A metal electrode of a certain thickness is plated on the vertical graphene film and patterned.

[0025] Furthermore, the micro grooves on the surface of the silicon wafer described in step 1 are processed by at least one of laser processing, physical etching, chemical etching and reactive ion etching.

[0026] Furthermore, the size of the micro-grooves processed in step 1 should satisfy that the inner depth of the groove is less than half of the inner width of the groove, and the inner width of the groove is less than the horizontal distance between the grooves.

[0027] Furthermore, the ultrasonic cleaning described in step 1 includes ultrasonic oscillation in acetone and ethanol for 10 minutes to 20 minutes respectively to remove the silicon wafer itself and pollutants generated during the processing.

[0028] Furthermore, the diameter of the cross-sectional dimension of the molybdenum wire described in step 2 must be no less than the width inside the groove and less than the horizontal distance between the grooves.

[0029] Furthermore, the preparation method described in step 3 may be a method of direct current arc plasma jet chemical vapor deposition (DCarc plasma jet CVD) or microwave plasma chemical vapor deposition (MPCVD).

[0030] Furthermore, the thickness of the diamond regrown after achieving full coverage of the silicon wafer and the molybdenum wire as described in step 3 is 1-3 mm.

[0031] Furthermore, the grinding and polishing method described in step 3 is to first laser cut 0.5-0.8 mm thick diamond from the diamond growth surface, and then use a grinder and a polisher to make its surface roughness (RMS) reach 0.001-0.05 μm.

[0032] Furthermore, the laser processing method described in step 3 is to use Nd:YAG laser beam to cut diamond.

[0033] Furthermore, the micro-groove dimensions described in step 3 should satisfy the requirements that the depth is no greater than 0.5 mm, the internal width of the groove is no less than twice the depth, and the horizontal distance between the grooves is greater than the internal width of the groove.

[0034] Furthermore, the acid treatment solution in step 3 is ultrasonically cleaned or boiled in high temperature acid using one of hydrochloric acid, sulfuric acid, and nitric acid or a mixed solution, and then ultrasonically cleaned using acetone and alcohol.

[0035] Furthermore, the molybdenum wire size described in step 4 should be the same length as the length of the diamond micro-groove, and the cross-sectional diameter should be no less than the internal width of the diamond micro-groove and less than the horizontal distance between the grooves, preferably consistent with the internal width of the micro-groove.

[0036] Furthermore, the thickness of the diamond regrown after the full coverage of the diamond substrate and the molybdenum wire as described in step 5 is 0.5-1.5 mm.

[0037] Furthermore, the acid treatment in step 6 is ultrasonic cleaning using a mixed solution of aqua regia, hydrochloric acid, sulfuric acid, nitric acid, etc., or boiling with high-temperature concentrated sulfuric acid, and finally ultrasonic cleaning using acetone and alcohol.

[0038] Furthermore, the preparation method of the vertical graphene described in step 7 is radio frequency plasma enhanced chemical vapor deposition (RF-PECVD), the process parameters are temperature 600℃-900℃, air pressure 50-150Pa, radio frequency power 150-300W, introduction of methane and hydrogen mixed gas, the ratio of CH4:H2=0.5-3, growth 0.5-2h, and the thickness of the grown film is 0.3-1.0μm; high temperature annealing in H2 gas atmosphere for 30-60min before growth.

[0039] Furthermore, the plating method described in step 8 adopts at least one of electron beam evaporation and magnetron sputtering, and the electrode material adopts Cr / Au with thicknesses of 3 / 10nm-10 / 50nm respectively.

[0040] Furthermore, the patterning method of step 8 is coating, exposure and development, etching and stripping.

[0041] The key to the implementation of the present invention is:

[0042] 1. The micro-groove size satisfies that the internal width of the groove is less than the horizontal distance between the grooves. Silicon wafer and diamond micro-grooves are part of the liquid flow channel and also the guarantee for fixing the molybdenum wire. Too wide internal grooves will cause the molybdenum wires to stack with each other, affecting the subsequent preparation of diamond-based liquid flow channels.

[0043] 2. The size of the molybdenum wire must be consistent and not less than the width of the groove inside and less than the horizontal distance between the grooves. Molybdenum wire is used as a metal mask for preparing diamond film to form an ultra-fast cooling structure for the liquid flow channel. The appropriate size can ensure that the molybdenum wire is fixed flat on the micro-groove and that the heat dissipation of the liquid flow channel is uniform.

[0044] 3. After the diamond grows to fully cover the substrate and the molybdenum wire surface, a certain thickness of diamond is grown. In the early stage of growth, a low proportion of methane gas must be maintained to prevent the diamond on the molybdenum wire from growing too fast, and to ensure that the diamond deposition growth is uniform and connected with the subsequent lateral expansion of diamond. After fully covering the molybdenum wire and the substrate to achieve the preparation of the diamond film, a certain thickness of epitaxial growth is required to facilitate subsequent processing.

[0045] 4. Use acid to treat molybdenum wire. It can not only remove the molybdenum wire, but also effectively remove the graphite carbon produced after machining, grinding and polishing diamond. Finally, use acetone and alcohol ultrasonic cleaning to remove organic matter and possible metal residues.

[0046] 5. Prepare a vertical graphene film on the flat surface of the silicon substrate with a diamond-based liquid flow channel, and the thickness of the grown film is 0.3-1.0μm. The thickness of the graphene film can be adjusted through various process parameters. Too thin will lead to low light absorption rate, affecting the photoelectric conversion efficiency and thus the responsiveness, while too thick will be unfavorable for subsequent device processing.

[0047] The advantages of the present invention are:

[0048] 1. The ultrafast cooling structure provided by the present invention combines the high thermal conductivity of diamond and the higher heat transfer capacity of microchannels compared with traditional heat dissipation structures. When used, it is supplemented with flowing liquid as a cooling medium to dissipate the heat generated by the operation of the device with extremely high efficiency.

[0049] 2. The two layers of mutually perpendicular liquid flow channels designed in the present invention ensure the temperature stability of the liquid flow channel in the middle layer through the pure diamond-based liquid flow channel in the bottom layer, thereby achieving continuous heat dissipation of the photodetector by the liquid flow channel in the middle layer, effectively suppressing the temperature rise of the device to ensure reliability and life.

[0050] 3. The vertical graphene used in the present invention grows directly on the silicon wafer, avoiding various problems caused by traditional transfer technology and simplifying the preparation process. The graphene film has the advantages of precise thickness control, strong repeatability, wide spectrum absorption, and high photoelectric conversion rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A schematic diagram of the three-dimensional structure of the photodetector with an ultrafast cooling structure of the present invention;

[0052] In the figure: 1.1-diamond, 1.2-silicon, 1.3-vertical graphene, 1.4-metal drain, 1.5-metal source, 1.6-first layer liquid flow channel, 1.7-second layer liquid flow channel.

[0053] Figure 2 The present invention is a flow chart of the preparation of a photodetector with an ultrafast cooling structure;

[0054] In the figure: (a) - pretreatment of silicon substrate, (b) - placement of molybdenum wire, (c) - preparation of diamond, processing of microgrooves and acid treatment, (d) - placement of new molybdenum wire, (e) - preparation and processing of the second layer of diamond film, (f) - removal of molybdenum wire, (g) - preparation of vertical graphene, (h) - fabrication of photodetector; 2.1 - silicon, 2.2 - molybdenum wire, 2.3 - diamond, 2.4 - first layer liquid flow channel, 2.5 - second layer liquid flow channel, 2.6 - vertical graphene, 2.7 - metal drain, 2.8 - metal source. DETAILED DESCRIPTION

[0055] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0056] Example 1

[0057] 1) A micro-groove structure was fabricated on the surface of a polished silicon wafer by laser processing, with a groove depth of 150 μm, a groove width of 300 μm, and a horizontal distance between grooves of 300 μm; the processed silicon wafer was cleaned by ultrasonic cleaning with acetone for 20 min, then transferred to alcohol for ultrasonic cleaning for 20 min, and then dried for use;

[0058] 2) A molybdenum wire with a diameter of 0.3 mm is placed on the micro-grooves of the silicon wafer;

[0059] 3) Place the silicon wafer filled with molybdenum wire in a microwave plasma chemical vapor deposition device to prepare deposited diamond. After preparing diamond to fully cover the surface of the silicon wafer and molybdenum wire, grow 2mm thick diamond, and cut and remove 0.5mm thick diamond after growth. Then grind and polish until the roughness reaches RMS=50nm, and use Nd:YAG laser beam to cut the diamond surface to prepare micro-grooves with a depth of 200μm, a width of 400μm, and a horizontal distance of 400μm. Finally, place the diamond in a nitric acid solution for ultrasonic cleaning, and then use acetone ultrasonic cleaning for 20min, then transfer to alcohol for ultrasonic cleaning for 20min, and then dry.

[0060] 4) Select a molybdenum wire with a diameter of 0.4 mm and place it on the micro groove of the diamond;

[0061] 5) Place the diamond filled with molybdenum wire in a microwave plasma chemical vapor deposition device to prepare deposited diamond. Prepare diamond to fully cover the diamond substrate and the surface of the molybdenum wire, then grow 1.2 mm thick diamond, and then grind and polish until the roughness reaches RMS = 10 nm.

[0062] 6) The polished diamond is placed in a concentrated sulfuric acid solution for acid boiling to effectively remove the molybdenum wire and the non-diamond carbon in the microchannel and generated by processing, thereby obtaining a silicon wafer with an ultrafast cooling structure. It is then ultrasonically cleaned with acetone for 20 minutes, then transferred to alcohol for ultrasonic cleaning for 20 minutes, and then dried.

[0063] 7) Place the silicon substrate with ultrafast cooling structure with its flat surface facing up in a radio frequency plasma enhanced chemical vapor deposition furnace to deposit a vertical graphene film. The growth temperature is 750°C, the radio frequency power is 300W, the working gas pressure is maintained at 50Pa, CH4:H2=1.5, the growth time is 45min, and the thickness of the grown film is 0.4μm; before growth, high temperature annealing is performed in a H2 gas atmosphere for 30min.

[0064] 8) Spin-coat the photoresist onto the vertical graphene and use photolithography to expose the electrode pattern; plate Cr / Au electrodes on the surface of the vertical graphene film by electron beam evaporation, with a thickness of 10nm / 20nm respectively. Graphically pattern the device by a stripping process, remove the previous photoresist to obtain a photodetector with an ultrafast cooling structure;

[0065] Example 2

[0066] 1) A micro-groove structure was fabricated on the surface of a polished silicon wafer by laser processing, with a groove depth of 20 μm, a groove width of 50 μm, and a horizontal distance of 50 μm between grooves; the processed silicon wafer was cleaned by ultrasonic cleaning with acetone for 20 min, then transferred to alcohol for ultrasonic cleaning for 20 min, and then dried for use;

[0067] 2) Select a molybdenum wire with a diameter of 0.05 mm and place it on the micro-groove of the silicon wafer;

[0068] 3) Place the silicon wafer filled with molybdenum wire in a DC arc plasma jet chemical vapor deposition device to prepare deposited diamond. After preparing diamond to fully cover the surface of the silicon wafer and molybdenum wire, grow 2mm thick diamond, and cut and remove 0.6mm thick diamond after growth. Then grind and polish until the roughness reaches RMS=50nm, and use Nd:YAG laser beam to cut the diamond surface to prepare micro-grooves with a depth of 100μm, a width of 200μm, and a horizontal distance of 200μm. Finally, place the diamond in concentrated hydrochloric acid for ultrasonic cleaning, and then use acetone for ultrasonic cleaning for 20min, then transfer to alcohol for ultrasonic cleaning for 20min, and then dry.

[0069] 4) Select a molybdenum wire with a diameter of 0.2 mm and place it on the micro groove of the diamond;

[0070] 5) Place the diamond filled with molybdenum wire in a DC arc plasma jet chemical vapor deposition device to prepare deposited diamond. Prepare diamond until the diamond substrate and the surface of the molybdenum wire are fully covered, then grow 1mm thick diamond, and then grind and polish until the roughness reaches RMS = 20nm.

[0071] 6) The polished diamond is placed in a concentrated sulfuric acid solution for acid boiling to effectively remove the molybdenum wire and the non-diamond carbon in the microchannel and generated by processing, thereby obtaining a silicon wafer with an ultrafast cooling structure. It is then ultrasonically cleaned with acetone for 20 minutes, then transferred to alcohol for ultrasonic cleaning for 20 minutes, and then dried.

[0072] 7) Place the silicon substrate with ultrafast cooling structure with its flat surface facing up in a radio frequency plasma enhanced chemical vapor deposition furnace to deposit a vertical graphene film. The growth temperature is 700°C, the radio frequency power is 250W, the working gas pressure is maintained at 50Pa, CH4:H2=1, the growth time is 1h, and the thickness of the grown film is 1.0μm. Before growth, high temperature annealing is performed in a H2 gas atmosphere for 30min.

[0073] 8) Spin-coat the photoresist onto the vertical graphene and use photolithography to expose the electrode pattern; use electron beam evaporation to plate Cr / Au electrodes with a thickness of 10nm / 40nm on the surface of the vertical graphene film. Use the lift-off process to pattern the device and remove the previous photoresist to obtain a photodetector with an ultrafast cooling structure.

[0074] Example 3

[0075] 1) A micro-groove structure was fabricated on the surface of a polished silicon wafer by laser processing, with a groove depth of 100 μm, a groove width of 400 μm, and a horizontal distance between grooves of 400 μm; the processed silicon wafer was cleaned by ultrasonic cleaning with acetone for 20 min, then transferred to alcohol for ultrasonic cleaning for 20 min, and then dried for use;

[0076] 2) Select a molybdenum wire with a diameter of 0.4 mm and place it on the micro-groove of the silicon wafer;

[0077] 3) Place the silicon wafer filled with molybdenum wire in a DC arc plasma jet chemical vapor deposition device to prepare deposited diamond. After preparing diamond to fully cover the surface of the silicon wafer and molybdenum wire, grow 3mm thick diamond, and cut and remove 0.8mm thick diamond after growth. Then grind and polish until the roughness reaches RMS=20nm, and use Nd:YAG laser beam to cut the diamond surface to prepare micro-grooves with a depth of 100μm, a width of 600μm, and a horizontal distance of 700μm. Finally, place the diamond in aqua regia for ultrasonic cleaning, and then use acetone for ultrasonic cleaning for 20min, then transfer to alcohol for ultrasonic cleaning for 20min, and then dry.

[0078] 4) Select a molybdenum wire with a diameter of 0.6 mm and place it on the micro groove of the diamond;

[0079] 5) Place the diamond filled with molybdenum wire in a microwave plasma chemical vapor deposition device to prepare deposited diamond. Prepare diamond until the diamond substrate and the surface of the molybdenum wire are fully covered, then grow 0.8mm thick diamond, and then grind and polish until the roughness reaches RMS = 1nm.

[0080] 6) The polished diamond is placed in a concentrated sulfuric acid solution for acid boiling to effectively remove the molybdenum wire and the non-diamond carbon in the microchannel and generated by processing, thereby obtaining a silicon wafer with an ultrafast cooling structure. It is then ultrasonically cleaned with acetone for 20 minutes, then transferred to alcohol for ultrasonic cleaning for 20 minutes, and then dried.

[0081] 7) Place the silicon substrate with ultrafast cooling structure with its flat surface facing up in a radio frequency plasma enhanced chemical vapor deposition furnace to deposit a vertical graphene film. The growth temperature is 650°C, the radio frequency power is 230W, the working gas pressure is maintained at 60Pa, CH4:H2=1, the growth time is 1h, and the thickness of the grown film is 0.7μm. Before growth, high temperature annealing is performed in a H2 gas atmosphere for 45min.

[0082] 8) Spin-coat the photoresist onto the vertical graphene and use photolithography to expose the electrode pattern; plate Cr / Au electrodes on the surface of the vertical graphene film by electron beam evaporation, with thicknesses of 3nm / 20nm respectively. Pattern the device by a stripping process, remove the previous photoresist, and obtain a photodetector with an ultrafast cooling structure;

[0083] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a photodetector with an ultrafast cooling structure, characterized in that: Placing a molybdenum wire on a silicon substrate with microgrooves to grow a diamond film, processing the diamond film with new microgrooves and then placing the molybdenum wire again to deposit diamonds, preparing two layers of mutually perpendicular diamond-based liquid flow channels to obtain an ultrafast cooling structure, then depositing a vertical graphene film on a flat surface of a silicon wafer with an ultrafast cooling structure, and finally plating a metal electrode on the vertical graphene and patterning it to prepare a photodetector with an ultrafast cooling structure; The specific preparation steps are as follows: Step 1, silicon substrate pretreatment: micro-groove processing is performed on the surface of the polished silicon wafer, and the processed silicon wafer is ultrasonically cleaned; Step 2, placing molybdenum wire: select molybdenum wire of consistent size and place it on the micro-groove of the silicon wafer; Step 3, preparation of diamond, processing of micro-grooves and acid treatment: the silicon wafer with the micro-grooves filled with molybdenum wire is used as a substrate for diamond growth, and is placed in a deposition device to prepare diamond until the surface of the silicon wafer and the molybdenum wire is fully covered, and then a certain thickness of diamond is grown, and the deposited diamond is ground and polished, and then the micro-grooves are processed by laser in a direction perpendicular to the molybdenum wire and acid treatment is performed; Step 4, place new molybdenum wire: select molybdenum wire of consistent size and place it on the micro groove of diamond; Step 5, preparation and processing of the second layer of diamond film: the diamond filled with molybdenum wire is placed in a deposition device to prepare a second layer of diamond film, the diamond grows to fully cover the diamond substrate and the surface of the molybdenum wire, and then grows to a certain thickness, and the grown diamond is ground and polished; Step 6, removing the molybdenum wire: using acid to treat the molybdenum wire between the diamonds to obtain two layers of mutually perpendicular liquid flow channels; Step 7, preparation of vertical graphene: preparing a vertical graphene film on a flat surface of a silicon substrate having a liquid flow channel; Step 8, preparation of photodetector: a metal electrode of a certain thickness is plated on the vertical graphene film and patterned.

2. The method for preparing a photodetector having an ultrafast cooling structure according to claim 1, characterized in that: The size of the micro-grooves processed in step 1 should satisfy that the inner depth of the groove is less than half of the inner width of the groove, and the inner width of the groove is less than the horizontal distance between the grooves.

3. The method for preparing a photodetector having an ultrafast cooling structure according to claim 1, characterized in that: The diameter of the molybdenum wire in step 2 must be no less than the width inside the groove and less than the horizontal distance between the grooves.

4. The method for preparing a photodetector having an ultrafast cooling structure according to claim 1, characterized in that: The thickness of the diamond regrown after achieving full coverage of the silicon wafer and the molybdenum wire as described in step 3 is 1-3 mm.

5. The method for preparing a photodetector having an ultrafast cooling structure according to claim 1, characterized in that: The grinding and polishing method described in step 3 is to first laser cut 0.5-0.8 mm thick diamond on the diamond growth surface, and then use a grinder and a polisher to make its surface roughness (RMS) reach 0.001-0.05 μm.

6. The method for preparing a photodetector having an ultrafast cooling structure according to claim 1, characterized in that: The micro-groove dimensions described in step 3 should satisfy the requirements that the depth is no greater than 0.5 mm, the internal width of the groove is no less than twice the depth, and the horizontal distance between the grooves is greater than the internal width of the groove.

7. The method for preparing a photodetector having an ultrafast cooling structure according to claim 1, characterized in that: The molybdenum wire size described in step 4 should be the same as the length of the diamond micro-groove, and the cross-sectional diameter should be not less than the internal width of the diamond micro-groove and less than the horizontal distance between the grooves, preferably consistent with the internal width of the micro-groove.

8. The method for preparing a photodetector having an ultrafast cooling structure according to claim 1, characterized in that: After the diamond substrate and the molybdenum wire are fully covered as described in step 5, the thickness of the regrown diamond is 0.5-1.5 mm.

9. The method for preparing a photodetector having an ultrafast cooling structure according to claim 1, characterized in that: The vertical graphene described in step 7 is prepared by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD), and the thickness of the grown film is 0.3-1.0 μm; before growth, it is annealed at high temperature in a H2 gas atmosphere for 30-60 minutes.

10. The method for preparing a photodetector having an ultrafast cooling structure according to claim 8, characterized in that: The plating method described in step 6 adopts at least one of electron beam evaporation and magnetron sputtering, the electrode material adopts Cr / Au, and the thickness is 3 / 10nm-10 / 50nm respectively, and the patterning method is coating, exposure and development, etching and stripping.

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