Preparation method of high-performance SiC single-photon ultraviolet detector and detector
By employing a three-dimensional fabrication method in SiC single-photon detectors, and utilizing a combination of hemispherical etching masks and functional layers, the problems of increased power consumption and limited gain were solved, thus realizing a high-performance SiC single-photon ultraviolet detector.
Patent Information
- Application Number
- CN202411927804.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2026-02-06
- Estimated Expiration
- 2044-12-25
AI Technical Summary
Existing SiC single-photon detectors have increased power consumption and relatively limited gain, making it difficult to achieve efficient detection at high voltages.
A method for fabricating a three-dimensional SiC single-photon ultraviolet detector involves preparing hemispherical etching masks arranged at intervals on the surface of an n+ type SiC epitaxial layer, combining photolithography and etching processes to form n+, n-, and p+ type epitaxial layers, and finally preparing an anode electrode and a back reflector layer to form a three-dimensional hemispherical structure.
The detector's resistance was reduced, the operating voltage was increased, and the detector's performance gain was enhanced. The high electric field was balanced by the three-dimensional structure, which reduced power consumption. At the same time, no additional optical management structure was required, which reduced the fabrication cost.
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Figure CN119815967B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of semiconductor optoelectronic devices, and particularly relates to a preparation method of a high-performance SiC single-photon ultraviolet detector and the detector. BACKGROUND
[0002] Wide-bandgap semiconductor materials such as silicon carbide (SiC), gallium nitride (GaN), and diamond (C) all have a wide band gap, can detect ultraviolet light in the 200-380 nm band under a strong visible and infrared background, and have the characteristics of high temperature resistance, high efficiency, and high reliability, and are ideal materials for preparing ultraviolet photodetectors. As a new type of third-generation semiconductor material, SiC has the characteristics of large band gap, high electron drift speed, high critical breakdown field strength, high thermal conductivity, and excellent chemical stability. SiC material has great application potential in high temperature, high power, optoelectronics, and radiation resistance. The SiC single-photon detector is a kind of optoelectronic device that uses SiC material to realize single-photon detection, and has wide application prospects in the fields of quantum communication, quantum computing, laser radar (Light Detection and Ranging, LiDAR), and biological imaging.
[0003] At present, for the preparation of the SiC single-photon detector, a vertical structure with an inclined mesa terminal is usually adopted to prepare a two-dimensional structure SiC single-photon detector. However, the two-dimensional structure has limited ability to regulate the electric field of the detector, so that the detector is often based on a low-concentration epitaxial layer to realize a high working voltage. The low concentration increases the power consumption of the detector and the relatively limited gain. SUMMARY
[0004] The purpose of the embodiments of the present application is to provide a preparation method of a high-performance SiC single-photon ultraviolet detector and the detector, and to solve the problems of increased power consumption and relatively limited gain of the detector.
[0005] To solve the above technical problems, the embodiments of the present application provide the following technical solutions:
[0006] The first aspect of the present application provides a preparation method of a high-performance SiC single-photon ultraviolet detector, comprising:
[0007] growing a preset n+ type SiC epitaxial layer on the surface of the n+ type SiC substrate;
[0008] utilizing the annealing reflow characteristics of alkali earth doped silicon oxide to prepare a spaced arrangement of hemispherical etching masks on the surface of the preset n+ type SiC epitaxial layer;
[0009] The preset n+ type SiC epitaxial layer is etched by using a hemispherical etching mask to obtain an n+ type SiC epitaxial layer, and the n+ type SiC epitaxial layer has a hemispherical shape;
[0010] An n-type SiC epitaxial layer and a p+ type SiC epitaxial layer are sequentially epitaxially grown on the surface of the n+ type SiC epitaxial layer;
[0011] A preset Si y N x passivation layer is formed on the surface of the p+ type SiC epitaxial layer and part of the surface of the n+ type SiC substrate;
[0012] The preset Si y N x passivation layer on the surface of the p+ type SiC epitaxial layer is windowed by using a photoetch process and an etching process to obtain Si y N x passivation layer;
[0013] An anode electrode is prepared on part of the surface of the p+ type SiC epitaxial layer, and a cathode electrode and a back reflector are sequentially prepared on the back surface of the n+ type SiC substrate to obtain a high-performance SiC single-photon ultraviolet detector.
[0014] In some embodiments, the annealing and reflow characteristics of an alkaline earth doped silicon oxide are used to prepare a hemispherical etching mask arranged at intervals on the surface of the preset n+ type SiC epitaxial layer, including:
[0015] An alkaline earth doped silicon oxide mask is deposited on the preset n+ type SiC epitaxial layer;
[0016] The alkaline earth doped silicon oxide mask is windowed by using a photoetch process and an etching process;
[0017] The windowed alkaline earth doped silicon oxide mask is annealed by using a rapid thermal annealing process to form a hemispherical etching mask.
[0018] In some embodiments, an anode electrode is prepared on part of the surface of the p+ type SiC epitaxial layer, and a cathode electrode and a back reflector are sequentially prepared on the back surface of the n+ type SiC substrate to obtain a high-performance SiC single-photon ultraviolet detector, including:
[0019] The front surface and the back surface of the device as a whole are both deposited with a first Ni metal after the Si y N x passivation layer is obtained;
[0020] The first Ni metal is annealed by using a rapid thermal annealing process in an inert atmosphere to form a preset anode electrode and a cathode electrode;
[0021] The preset anode electrode is cleaned by using the No. 3 liquid, and the anode electrode is obtained.
[0022] The Ti metal, the second Ni metal and the Ag metal are deposited on the back surface of the cathode electrode by using an electron beam evaporation process to form a back reflection layer, and a high-performance SiC single-photon ultraviolet detector is obtained.
[0023] In some embodiments, the n+ type SiC substrate has a thickness of 350 mu m and a concentration of 5e18.
[0024] In some embodiments, the preset n+ type SiC epitaxial layer has a thickness of 8-10 mu m and a concentration of 1e16-5e16.
[0025] In some embodiments, the alkali earth doped silicon oxide mask has a thickness of 2000 nm, and the radius of the hemispherical etching mask is 500-1000 nm.
[0026] In some embodiments, the annealing temperature of the rapid thermal annealing process used by the hemispherical etching mask is 1000 DEG C, and the annealing time is 120 s.
[0027] In some embodiments, the annealing temperature of the rapid thermal annealing process used by the preset anode electrode and the cathode electrode is 1050 DEG C, and the annealing time is 120 s.
[0028] In some embodiments, the thicknesses of the first Ni metal, the Ti metal and the second Ni metal are all 200 nm, and the thickness of the Ag metal is 800 nm.
[0029] The second aspect of the present application provides a high-performance SiC single-photon ultraviolet detector, comprising:
[0030] a back reflection layer, a cathode electrode and an n+ type SiC substrate arranged in sequence from bottom to top;
[0031] n+ type SiC epitaxial layers formed on the surface of the n+ type SiC substrate and arranged at intervals, and the n+ type SiC epitaxial layers have a hemispherical shape;
[0032] n- type SiC epitaxial layers formed on the surface of the n+ type SiC epitaxial layers and in contact with the n+ type SiC substrate;
[0033] p+ type SiC epitaxial layers formed on the surface of the n- type SiC epitaxial layers and in contact with the n+ type SiC substrate;
[0034] an anode electrode formed on the surface of part of the p+ type SiC epitaxial layers;
[0035] Si y N xA passivation protective layer is formed on the surface of a portion of the p+ type SiC epitaxial layer and in the region between the p+ type SiC epitaxial layer, and is in contact with the anode electrode and the n+ type SiC substrate.
[0036] Compared to existing technologies, the high-performance SiC single-photon ultraviolet detector fabrication method and detector provided by this invention involve growing a predetermined n+ type SiC epitaxial layer on the surface of an n+ type SiC substrate; utilizing the annealing and reflow characteristics of alkaline earth-doped silicon oxide, preparing a spaced hemispherical etching mask on the surface of the predetermined n+ type SiC epitaxial layer; using the hemispherical etching mask, etching the predetermined n+ type SiC epitaxial layer to obtain an n+ type SiC epitaxial layer with a hemispherical shape; sequentially epitaxially growing an n- type SiC epitaxial layer and a p+ type SiC epitaxial layer on the surface of the n+ type SiC epitaxial layer; and growing a predetermined SiC epitaxial layer on the surface of the p+ type SiC epitaxial layer and part of the surface of the n+ type SiC substrate. y N x Passivation protective layer; using photolithography and etching processes, a portion of the surface of the p+ type SiC epitaxial layer is pre-stressed with Si. y N x The passivation protective layer is windowed to obtain Si. y N x A passivation protective layer is applied; an anode electrode is fabricated on the surface of a portion of the p+ type SiC epitaxial layer, and a cathode electrode and a back reflector layer are sequentially fabricated on the back side of the n+ type SiC substrate to obtain a high-performance SiC single-photon ultraviolet detector. In this way, the annealing and reflow characteristics of alkaline earth-doped silicon oxide are used to fabricate a three-dimensional hemispherical etching mask. Based on this three-dimensional hemispherical etching mask, the final high-performance SiC single-photon ultraviolet detector contains a three-dimensional hemispherical structure. The three-dimensional hemispherical structure can balance the high electric field, and the use of three highly doped functional layers—an n+ type SiC epitaxial layer, an n- type SiC epitaxial layer, and a p+ type SiC epitaxial layer—can reduce the detector's resistance to lower power consumption and enable the detector to have a higher operating voltage to achieve higher detector performance gain. Attached Figure Description
[0037] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the invention are illustrated by way of example and not limitation, with the same or corresponding reference numerals denoteing the same or corresponding parts, wherein:
[0038] Figure 1 A schematic flowchart illustrating the fabrication method of a high-performance SiC single-photon ultraviolet detector is shown.
[0039] Figure 2 A schematic diagram of the growth of a pre-defined n+ type SiC epitaxial layer is shown.
[0040] Figure 3 A schematic view of growing an alkaline earth doped silicon oxide mask is shown schematically;
[0041] Figure 4 A schematic view of opening the alkaline earth doped silicon oxide mask is shown schematically;
[0042] Figure 5 A schematic view of annealing the alkaline earth doped silicon oxide mask is shown schematically;
[0043] Figure 6 A schematic view of etching the n+ SiC epitaxy is shown schematically;
[0044] Figure 7 A schematic view of epitaxially growing the n- SiC epitaxial layer is shown schematically;
[0045] Figure 8 A schematic view of epitaxially growing the p+ SiC epitaxial layer is shown schematically;
[0046] Figure 9 A schematic view of surface passivating the SiC is shown schematically; y N x A schematic view of the passivation protection layer is shown schematically;
[0047] Figure 10 A schematic view of forming the electrode is shown schematically;
[0048] Figure 11 A schematic view of forming the back reflector is shown schematically;
[0049] Figure 12 A schematic view of the structure of the high performance SiC single photon UV detector is shown schematically.
[0050] BRIEF DESCRIPTION OF DRAWINGS
[0051] 1. n+ SiC substrate; 2. n+ SiC epitaxial layer; 3. n- SiC epitaxial layer; 4. p+ SiC epitaxial layer; 5. Si y N x passivation protection layer; 6. anode electrode; 7. cathode electrode; 8. back reflector. DETAILED DESCRIPTION
[0052] The embodiments of the present application will be further described in conjunction with the drawings and examples. The following detailed description and examples are intended to illustrate the principles of the present application, but not to limit the scope of the present application, which can be realized in many different forms, not limited to the specific embodiments disclosed herein, and includes all technical solutions falling within the scope of the claims.
[0053] The preparation method of the high-performance SiC single-photon ultraviolet detector is specifically described below.
[0054] Referring to Figure 1 as shown in the figure, Figure 1 The preparation method of the high-performance SiC single-photon ultraviolet detector is specifically described below.
[0055] S101, growing a preset n+ type SiC epitaxial layer 2 on the surface of the n+ type SiC substrate 1.
[0056] The thickness of the n+ type SiC substrate 1 is 350 μm, and the concentration is 5e18. The thickness of the preset n+ type SiC epitaxial layer 2 is 8-10 μm, and the concentration is 1e16-5e16. The preset n+ type SiC epitaxial layer 2 is an n+ functional layer.
[0057] Figure 2 The growth of the preset n+ type SiC epitaxial layer 2 is schematically shown. On the surface of the n+ type SiC substrate 1, the preset n+ type SiC epitaxial layer 2 with a thickness of 8-10 μm and a concentration of 1e16-5e16 is grown.
[0058] S102, using the annealing and reflow characteristics of alkaline earth doped silicon oxide to prepare a semispherical etching mask arranged at intervals on the surface of the preset n+ type SiC epitaxial layer 2.
[0059] Specifically, using the annealing and reflow characteristics of alkaline earth doped silicon oxide to prepare a semispherical etching mask arranged at intervals on the surface of the preset n+ type SiC epitaxial layer 2, comprising:
[0060] Step A1: depositing an alkaline earth doped silicon oxide mask on the preset n+ type SiC epitaxial layer 2.
[0061] The thickness of the alkaline earth doped silicon oxide mask is 2000 nm.
[0062] Specifically, Figure 3 The growth of the alkaline earth doped silicon oxide mask is schematically shown. Using a low pressure chemical vapor deposition (LPCVD) process, an alkaline earth doped silicon oxide etching mask with a thickness of 2000 nm is deposited on the entire surface of the preset n+ type SiC epitaxial layer 2.
[0063] Step A2: using a photolithography process and an etching process to open a window for the alkaline earth doped silicon oxide mask.
[0064] Specifically, Figure 4A schematic diagram of the alkaline earth doped silicon oxide mask windowing is shown. The alkaline earth doped silicon oxide mask is windowed using a photolithography and etching process. The windowing pattern is a circle. The windowing radius is 500nm-1000nm.
[0065] Step A3: The alkaline earth doped silicon oxide mask after windowing is annealed using a rapid thermal annealing process to form a hemispherical etching mask.
[0066] The radius of the hemispherical etching mask is 500nm-1000nm. The annealing temperature of the rapid thermal annealing process used by the hemispherical etching mask is 1000℃. The time is 120s.
[0067] Specifically, Figure 5 A schematic diagram of the alkaline earth doped silicon oxide mask annealing is shown. The alkaline earth doped silicon oxide mask after windowing is annealed using a rapid thermal annealing process to form a hemispherical etching mask. The annealing temperature is 1000℃. The time is 120s.
[0068] S103, using the hemispherical etching mask, etching the preset n+ type SiC epitaxial layer 2 to obtain the n+ type SiC epitaxial layer 2.
[0069] The shape of the n+ type SiC epitaxial layer 2 is hemispherical.
[0070] The n+ type SiC epitaxial layers 2 are arranged in intervals.
[0071] Specifically, Figure 6 A schematic diagram of the etching n+ type SiC epitaxial is shown. The preset n+ type SiC epitaxial layer 2 is etched to a hemispherical shape using the hemispherical etching mask as a mask to obtain the n+ type SiC epitaxial layer 2.
[0072] S104, sequentially epitaxially growing n- type SiC epitaxial layer 3 and p+ type SiC epitaxial layer 4 on the surface of the n+ type SiC epitaxial layer 2.
[0073] The n- type SiC epitaxial layer 3 and the p+ type SiC epitaxial layer 4 are arranged in intervals. The n- type SiC epitaxial layer 3 and the p+ type SiC epitaxial layer 4 are both semicircular ring shapes. The n- type SiC epitaxial layer 3 is an n- functional layer. The p+ type SiC epitaxial layer 4 is a p+ functional layer.
[0074] Specifically, Figure 7 A schematic diagram of the epitaxial growth of the n- type SiC epitaxial layer 3 is shown, Figure 8A schematic diagram of epitaxially growing a p+ type SiC epitaxial layer 4 is shown schematically. An n- type SiC epitaxial layer 3 and a p+ type SiC epitaxial layer 4 are epitaxially grown on the surface of the n+ type SiC epitaxial layer 2 in turn. The n- type SiC epitaxial layer 3 is composed of a semicircular ring-shaped portion and a square-shaped portion.
[0075] The square-shaped portion of the n- type SiC epitaxial layer 3 and the square-shaped portion of the p+ type SiC epitaxial layer 4 need to be etched, i.e. the portion between the n- type SiC epitaxial layer 3 of the semicircular ring-shaped portion and the portion between the p+ type SiC epitaxial layer 4 of the semicircular ring-shaped portion need to be etched.
[0076] S105, growing a preset Si y N x passivation protection layer 5 on the surface of the p+ type SiC epitaxial layer 4 and the surface of part of the n+ type SiC substrate 1, i.e. the n+ type SiC substrate 1 between the p+ type SiC epitaxial layer 4.
[0077] Specifically, Figure 9 A schematic diagram of surface passivation Si y N x passivation protection layer 5 is shown schematically. A preset Si y N x passivation protection layer 5, i.e. Si y N x surface passivation anti-reflection layer.
[0078] S106, using a photolithography process and an etching process to open a window on part of the preset Si y N x passivation protection layer 5 on the surface of the p+ type SiC epitaxial layer 4, to obtain Si y N x passivation protection layer 5.
[0079] S107, preparing an anode electrode 6 on part of the surface of the p+ type SiC epitaxial layer 4, and preparing a cathode electrode 7 and a back reflection layer 8 on the back surface of the n+ type SiC substrate 1 in turn, to obtain a high-performance SiC single-photon ultraviolet detector.
[0080] Specifically, Figure 10 A schematic diagram of forming an electrode is shown schematically, Figure 11 A schematic diagram of forming a back reflection layer 8 is shown schematically, as shown in Figure 10 and Figure 11 shown, an anode electrode 6 is prepared on part of the surface of the p+ type SiC epitaxial layer 4, and a cathode electrode 7 and a back reflection layer 8 are prepared on the back surface of the n+ type SiC substrate 1 in turn, to obtain a high-performance SiC single-photon ultraviolet detector, comprising:
[0081] Step B1: obtaining Si y N x The first Ni metal is deposited on the front surface and the back surface of the whole device of the passivation protective layer 5.
[0082] The thickness of the first Ni metal is 200 nm.
[0083] Step B2: annealing the first Ni metal by using a rapid thermal annealing process in an inert atmosphere to form the preset anode electrode 6 and the cathode electrode 7.
[0084] The annealing temperature of the rapid thermal annealing process used by the preset anode electrode 6 and the cathode electrode 7 is 1050 DEG C, and the time is 120 s.
[0085] Step B3: cleaning the preset anode electrode 6 by using the third liquid to obtain the anode electrode 6.
[0086] Step B4: depositing Ti metal, the second Ni metal and Ag metal on the back surface of the cathode electrode 7 by using an electron beam evaporation process to form the back reflection layer 8 and obtain the high-performance SiC single-photon ultraviolet detector.
[0087] The thicknesses of the Ti metal and the second Ni metal are both 200 nm, and the thickness of the Ag metal is 800 nm.
[0088] Based on the above Figure 1 It can be seen from the implementation mode of the present application that the preset n+ type SiC epitaxial layer 2 is grown on the surface of the n+ type SiC substrate 1; the annealing reflow characteristics of the alkali earth doped silicon oxide are used to prepare the interval arranged hemispherical etching mask on the surface of the preset n+ type SiC epitaxial layer 2; the preset n+ type SiC epitaxial layer 2 is etched by using the hemispherical etching mask to obtain the n+ type SiC epitaxial layer 2, and the shape of the n+ type SiC epitaxial layer 2 is a hemispherical shape; the n- type SiC epitaxial layer 3 and the p+ type SiC epitaxial layer 4 are epitaxially grown on the surface of the n+ type SiC epitaxial layer 2 in sequence; the preset Si y N x passivation protective layer 5 is grown on the surface of the p+ type SiC epitaxial layer 4 and part of the surface of the n+ type SiC substrate 1; the part of the preset Si y N x passivation protective layer 5 on the surface of the p+ type SiC epitaxial layer 4 is windowed by using a photoetching process and an etching process to obtain the Si y N xA passivation protective layer 5 is formed on the surface of the p+ type SiC epitaxial layer 4, an anode electrode 6 is formed on the surface of the p+ type SiC epitaxial layer 4, and a cathode electrode 7 and a back reflection layer 8 are formed on the back surface of the n+ type SiC substrate 1 in sequence to obtain the high-performance SiC single-photon ultraviolet detector. In this way, the annealing and reflow characteristics of the alkali earth doped silicon oxide are used to prepare the three-dimensional structure of the hemispherical etching mask, and the high-performance SiC single-photon ultraviolet detector finally obtained based on the three-dimensional structure of the hemispherical etching mask contains a three-dimensional hemispherical structure, the three-dimensional hemispherical structure can balance the high electric field, and the n+ type SiC epitaxial layer 2, the n- type SiC epitaxial layer 3 and the p+ type SiC epitaxial layer 4 are three functional layers with high doping concentration, which can reduce the resistance of the detector to reduce power consumption, and make the detector have higher working voltage to realize higher performance gain of the detector.
[0089] Based on the same inventive concept, the embodiment of the present application also provides a high-performance SiC single-photon ultraviolet detector. Figure 12 For the structure of the high-performance SiC single-photon ultraviolet detector in the embodiment of the present application, the high-performance SiC single-photon ultraviolet detector can include:
[0090] The back reflection layer 8, the cathode electrode 7 and the n+ type SiC substrate 1 are sequentially arranged from bottom to top;
[0091] The n+ type SiC epitaxial layer 2 is formed on the surface of the n+ type SiC substrate 1 and is arranged at intervals, and the shape of the n+ type SiC epitaxial layer 2 is a hemispherical shape;
[0092] The n- type SiC epitaxial layer 3 is formed on the surface of the n+ type SiC epitaxial layer 2 and is in contact with the n+ type SiC substrate 1;
[0093] The p+ type SiC epitaxial layer 4 is formed on the surface of the n- type SiC epitaxial layer 3 and is in contact with the n+ type SiC substrate 1;
[0094] The anode electrode 6 is formed on the surface of the p+ type SiC epitaxial layer 4;
[0095] Si y N x The passivation protective layer 5 is formed on the surface of the p+ type SiC epitaxial layer 4 and the region between the p+ type SiC epitaxial layer 4, and is in contact with the anode electrode 6 and the n+ type SiC substrate 1.
[0096] The embodiment of the present application uses the annealing reflow characteristics of alkali earth doped silicon oxide to prepare a three-dimensional hemispherical structure etching mask. Based on the mask, a three-dimensional hemispherical structure device can be etched to form a three-dimensional hemispherical structure that can balance high electric field. Compared with the existing two-dimensional structure, the electric field of the three-dimensional hemispherical structure expands more slowly. Therefore, under the same working voltage condition, the three-dimensional hemispherical structure can use a functional layer with a higher doping concentration, thereby reducing the resistance of the device, reducing power consumption, and improving the gain of the optical response of the device. In addition, the electric field expansion of the three-dimensional hemispherical structure is isotropic, and there is no obvious peak electric field, which can avoid the terminal design problem. In terms of optical performance, the functional area formed by the three-dimensional hemispherical structure array has a self-reduction optical management effect, and does not need to introduce additional optical management structures, which greatly reduces the preparation cost of the device. Moreover, the preparation method of the high-performance SiC single-photon ultraviolet detector can be realized by standard process, which does not bring additional budget such as equipment modification to the actual production, and can stably output related products.
[0097] Although some specific embodiments of the present application have been described in detail by examples, those skilled in the art should understand that the above examples are only for illustration, not for limiting the scope of the present application. Those skilled in the art should understand that the above embodiments can be modified or some technical features can be replaced equivalently without departing from the scope and spirit of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way.
[0098] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. A method for preparing a high-performance SiC single-photon ultraviolet detector, characterized in that, The application relates to a high-performance SiC single-photon ultraviolet detector. The application comprises the following steps: growing a preset n+ type SiC epitaxial layer on the surface of an n+ type SiC substrate; preparing a semispherical etching mask arranged at intervals on the surface of the preset n+ type SiC epitaxial layer by using the annealing and reflow characteristics of alkali earth doped silicon oxide; etching the preset n+ type SiC epitaxial layer by using the semispherical etching mask to obtain an n+ type SiC epitaxial layer, wherein the shape of the n+ type SiC epitaxial layer is semispherical; Growth of a predetermined Si on the surface of the p+ type SiC epitaxial layer and part of the surface of the n+ type SiC substrate y N x Passivation protective layer Utilizing a photoetching process and an etching process, a part of the preset Si on the surface of the p+ type SiC epitaxial layer is removed y N x A passivation protective layer is opened to obtain Si y N x A passivation protective layer sequentially epitaxially growing an n- type SiC epitaxial layer and a p+ type SiC epitaxial layer on the surface of the n+ type SiC epitaxial layer; 2. The method of claim 1, wherein the method further comprises: preparing an anode electrode on the surface of part of the p+ type SiC epitaxial layer and sequentially preparing a cathode electrode and a back reflection layer on the back of the n+ type SiC substrate to obtain the high-performance SiC single-photon ultraviolet detector. The step of preparing the semispherical etching mask arranged at intervals on the surface of the preset n+ type SiC epitaxial layer by using the annealing and reflow characteristics of alkali earth doped silicon oxide comprises the following steps: depositing an alkali earth doped silicon oxide mask on the preset n+ type SiC epitaxial layer; opening the alkali earth doped silicon oxide mask by using the photolithography process and the etching process; 3. The method of claim 1, wherein the method further comprises: annealing the opened alkali earth doped silicon oxide mask by using a rapid thermal annealing process to form the semispherical etching mask. The Si y N x The first Ni metal is deposited on the front and back surfaces of the whole device of the passivation protective layer. The step of preparing the anode electrode on the surface of part of the p+ type SiC epitaxial layer and sequentially preparing the cathode electrode and the back reflection layer on the back of the n+ type SiC substrate to obtain the high-performance SiC single-photon ultraviolet detector comprises the following steps: annealing the first Ni metal by using a rapid thermal annealing process in an inert atmosphere to form a preset anode electrode and the cathode electrode; cleaning the preset anode electrode by using the No. 3 liquid to obtain the anode electrode; 4. The method of claim 1, wherein the high-performance SiC single-photon ultraviolet detector is prepared by the steps of: depositing Ti metal, second Ni metal and Ag metal on the back of the cathode electrode by using an electron beam evaporation process to form the back reflection layer and obtain the high-performance SiC single-photon ultraviolet detector. 5. The method of claim 1, wherein the high performance SiC single photon ultraviolet detector is prepared by the steps of: The thickness of the n+ type SiC substrate is 350 mu m. 6. The method of claim 2, wherein the SiC single photon ultraviolet detector is a high performance SiC single photon ultraviolet detector. The thickness of the preset n+ type SiC epitaxial layer is 8-10 mu m.
7. The method of claim 2, wherein the SiC single photon ultraviolet detector is a high performance SiC single photon ultraviolet detector. The thickness of the alkali earth doped silicon oxide mask is 2000 nm, and the radius of the semispherical etching mask is 500-1000 nm.
8. The method of claim 3, wherein the SiC single photon ultraviolet detector is a high performance SiC single photon ultraviolet detector. The annealing temperature of the rapid thermal annealing process used by the semispherical etching mask is 1000 DEG C, and the time is 120 s.
9. The method of claim 3, wherein the SiC single photon ultraviolet detector is a high performance SiC single photon ultraviolet detector. The annealing temperature of the rapid thermal annealing process used by the preset anode electrode and the cathode electrode is 1050 DEG C, and the time is 120 s.
10. A high performance SiC single photon ultraviolet detector, characterized by, The thicknesses of the first Ni metal, the Ti metal and the second Ni metal are all 200 nm, and the thickness of the Ag metal is 800 nm. The application is suitable for the preparation method of the high-performance SiC single-photon ultraviolet detector. a back reflection layer, a cathode electrode and an n+ type SiC substrate arranged from bottom to top; n+ type SiC epitaxial layers formed on the surface of the n+ type SiC substrate and arranged at intervals, wherein the shape of the n+ type SiC epitaxial layers is semispherical; an n-type SiC epitaxial layer formed on a surface of the n+ type SiC epitaxial layer and in contact with the n+ type SiC substrate; a p+ type SiC epitaxial layer formed on a surface of the n- type SiC epitaxial layer and in contact with the n+ type SiC substrate; an anode electrode formed on a surface of a part of the p+ type SiC epitaxial layer; Si y N x a passivation protective layer formed in a region between a portion of the surface of the p+ type SiC epitaxial layer and the p+ type SiC epitaxial layer, and in contact with the anode electrode and the n+ type SiC substrate.
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