Preparation method of high-performance SiC single-photon ultraviolet detector and detector
By using the annealing reflux characteristics of alkaline earth-doped silicon oxide in the SiC single-photon detector, a hemispherical etch mask is prepared to form a three-dimensional hemispherical structure, the problems of increased power consumption and limited gain of SiC single-photon detector are solved, and lower power consumption and higher performance gain are achieved.
Patent Information
- Application Number
- CN202411927804.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2025-04-11
- Estimated Expiration
- 2044-12-25
AI Technical Summary
The problem of increasing power consumption and relatively limited gain of SiC single-photon detectors.
A preset n+ type SiC epitaxial layer is grown on the surface of an n+ type SiC substrate, and a spacing-arranged hemispherical etching mask is prepared using the annealing reflux characteristics of alkaline earth doped silicon oxide. The n+ type SiC epitaxial layer is etched through the hemispherical etching mask to form a hemispherical n+ type SiC epitaxial layer. Then n-type SiC and p+-type SiC epitaxial layers are epitaxially grown on its surface, and an anode electrode and a back reflective layer are prepared on the surface of the p+-type SiC epitaxial layer to form a high-performance SiC single-photon ultraviolet detector.
Through the design of a three-dimensional hemispherical structure, the high electric field is balanced, the resistance of the detector is reduced, the power consumption is reduced, and the detector's operating voltage and performance gain is improved.
Smart Images
Figure CN119815967A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of semiconductor optoelectronic devices, and in particular to a preparation method of a high-performance SiC single-photon ultraviolet detector and a detector. Background Art
[0002] Wide bandgap semiconductor materials such as silicon carbide (SiC), gallium nitride (GaN), and diamond (C) all have wide bandgaps and can detect ultraviolet light in the 200-380nm band under strong visible and infrared backgrounds. They are also resistant to high temperatures and have high efficiency and reliability, making them ideal materials for preparing ultraviolet photodetectors. As a new type of third-generation semiconductor material, silicon carbide (SiC) has the characteristics of large bandgap width, high electron drift velocity, high critical breakdown field strength, high thermal conductivity, and excellent chemical stability. SiC materials have great application potential in high temperature, high power, optoelectronics, and radiation resistance. SiC single-photon detectors are optoelectronic devices that use silicon carbide (SiC) materials to achieve single-photon detection. They have broad application prospects in quantum communications, quantum computing, LiDAR (Light Detection and Ranging), and bioimaging.
[0003] At present, the preparation of SiC single-photon detectors usually adopts a vertical structure with a tilted table terminal to prepare a two-dimensional SiC single-photon detector. However, the two-dimensional structure has limited control over the electric field of the detector, so the detector is often based on a low-concentration epitaxial layer to achieve a high operating voltage. The low concentration increases the number of electrons in the detector and increases power consumption, and the gain is relatively limited. Summary of the invention
[0004] The purpose of the embodiments of the present invention is to provide a method for preparing a high-performance SiC single-photon ultraviolet detector and a detector 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 invention provide the following technical solutions:
[0006] The first aspect of the present invention provides a method for preparing 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] By utilizing the annealing reflow characteristics of alkaline earth doped silicon oxide, a spaced hemispherical etching mask is prepared on the surface of a preset n+ type SiC epitaxial layer;
[0009] Using a hemispherical etching mask, etching a preset n+ type SiC epitaxial layer to obtain an n+ type SiC epitaxial layer, wherein the shape of the n+ type SiC epitaxial layer is a hemispherical shape;
[0010] epitaxially growing an n-type SiC epitaxial layer and a p+ type SiC epitaxial layer in sequence on the surface of the n+ type SiC epitaxial layer;
[0011] On the surface of the p+ type SiC epitaxial layer and part of the surface of the n+ type SiC substrate, a preset Si y N x Passivation protective layer;
[0012] Using photolithography and etching processes, the surface of the p+ type SiC epitaxial layer is partially pre-cut. y N x Passivation protection layer is opened to obtain Si y N x Passivation protective layer;
[0013] An anode electrode is prepared on the surface of a portion of the p+ type SiC epitaxial layer, and a cathode electrode and a back reflection layer are sequentially prepared on the back side of the n+ type SiC substrate to obtain a high-performance SiC single-photon ultraviolet detector.
[0014] In some embodiments, utilizing the annealing reflow characteristics of alkaline earth doped silicon oxide, preparing spaced hemispherical etching masks on the surface of a preset n+ type SiC epitaxial layer, including:
[0015] Depositing an alkaline earth doped silicon oxide mask on a preset n+ type SiC epitaxial layer;
[0016] Using photolithography and etching processes, windows are opened in the alkaline earth doped silicon oxide mask;
[0017] The alkaline earth doped silicon oxide mask after the window is opened 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 the surface of a portion of the p+ type SiC epitaxial layer, and a cathode electrode and a back reflection layer are sequentially prepared on the back side of the n+ type SiC substrate to obtain a high performance SiC single photon ultraviolet detector, including:
[0019] In getting Si y N x A first Ni metal is deposited on the front and back sides of the entire device of the passivation protection layer;
[0020] Annealing the first Ni metal 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 No. 3 liquid to obtain the anode electrode;
[0022] By using electron beam evaporation technology, Ti metal, a second Ni metal and Ag metal are deposited on the back of the cathode electrode to form a back reflection layer, thereby obtaining a high-performance SiC single-photon ultraviolet detector.
[0023] In some embodiments, the thickness of the n+ type SiC substrate is 350 μm and the concentration is 5e18.
[0024] In some embodiments, the thickness of the n+ type SiC epitaxial layer is preset to be 8-10 μm, and the concentration is preset to be 1e16-5e16.
[0025] In some embodiments, the thickness of the alkaline earth doped silicon oxide mask is 2000 nm, and the radius of the hemispherical etching mask is 500 nm to 1000 nm.
[0026] In some embodiments, the rapid thermal annealing process used for the hemispherical etch mask has an annealing temperature of 1000° C. and a time of 120 seconds.
[0027] In some embodiments, the annealing temperature of the rapid thermal annealing process used for the anode electrode and the cathode electrode is preset to be 1050° C. and the time is 120 seconds.
[0028] In some embodiments, the thickness 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] A second aspect of the present invention provides a high-performance SiC single-photon ultraviolet detector, comprising:
[0030] A back reflection layer, a cathode electrode and an n+ type SiC substrate are sequentially arranged from bottom to top;
[0031] n+ type SiC epitaxial layer, formed on the surface of n+ type SiC substrate and arranged at intervals, the shape of n+ type SiC epitaxial layer is hemispherical;
[0032] An n-type SiC epitaxial layer is formed on a surface of the n+ type SiC epitaxial layer and is in contact with the n+ type SiC substrate;
[0033] A p+ type SiC epitaxial layer is formed on a surface of the n-type SiC epitaxial layer and is in contact with the n+ type SiC substrate;
[0034] An anode electrode formed on the surface of a portion of the p+ type SiC epitaxial layer;
[0035] Si y N xThe passivation protection 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 layers, and is in contact with the anode electrode and the n+ type SiC substrate.
[0036] Compared with the prior art, the preparation method and detector of the high-performance SiC single-photon ultraviolet detector provided by the present invention include growing a preset n+ type SiC epitaxial layer on the surface of an n+ type SiC substrate; utilizing the annealing reflux characteristics of alkaline earth doped silicon oxide to prepare a spaced hemispherical etching mask on the surface of the preset n+ type SiC epitaxial layer; utilizing the hemispherical etching mask to etch the preset n+ type SiC epitaxial layer to obtain an n+ type SiC epitaxial layer, wherein the shape of the n+ type SiC epitaxial layer is a hemispherical shape; epitaxially growing an n- type SiC epitaxial layer and a p+ type SiC epitaxial layer in sequence on the surface of the n+ type SiC epitaxial layer; growing a preset Si on the surface of the p+ type SiC epitaxial layer and the surface of a portion of the n+ type SiC substrate y N x Passivation protection layer; using photolithography and etching processes, a portion of the surface of the p+ type SiC epitaxial layer is preset Si y N x Passivation protection layer is opened to obtain Si y N x Passivation protection layer; preparing an anode electrode on the surface of a portion 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 a high-performance SiC single-photon ultraviolet detector. In this way, the annealing reflux characteristics of alkaline earth doped silicon oxide are used to prepare a three-dimensional hemispherical etching mask, and the hemispherical etching mask based on the three-dimensional structure makes it possible to finally obtain a high-performance SiC single-photon ultraviolet detector comprising a three-dimensional hemispherical structure, which can balance the high electric field, and use the three high-doping concentration functional layers of the n+ type SiC epitaxial layer, the n-type SiC epitaxial layer and the p+ type SiC epitaxial layer, which can reduce the resistance of the detector to reduce power consumption, and make the detector have a higher operating voltage to achieve a higher detector performance gain. BRIEF DESCRIPTION OF THE DRAWINGS
[0037] By reading the detailed description below with reference to the accompanying drawings, the above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood. In the accompanying drawings, several embodiments of the present invention are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:
[0038] Figure 1 The flowchart of the method for preparing a high-performance SiC single-photon ultraviolet detector is schematically shown;
[0039] Figure 2 The schematic diagram of growing a preset n+ type SiC epitaxial layer is schematically shown;
[0040] Figure 3 Schematically shows a schematic diagram of growing an alkaline earth doped silicon oxide mask;
[0041] Figure 4 The schematic diagram of alkaline earth doped silicon oxide mask window opening is schematically shown;
[0042] Figure 5 Schematically shows a schematic diagram of annealing an alkaline earth doped silicon oxide mask;
[0043] Figure 6 Schematically shows a schematic diagram of etching n+ type SiC epitaxy;
[0044] Figure 7 Schematically shows a schematic diagram of epitaxial growth of an n-type SiC epitaxial layer;
[0045] Figure 8 Schematically shows a schematic diagram of epitaxial growth of a p+ type SiC epitaxial layer;
[0046] Fig. 9 Schematic diagram showing the surface passivation of Si y N x Schematic diagram of the passivation protection layer;
[0047] Fig.10 schematically shows a schematic diagram of forming an electrode;
[0048] Fig.11 Schematically shows a schematic diagram of forming a back reflection layer;
[0049] Fig.12 The structural diagram of a high-performance SiC single-photon ultraviolet detector is schematically shown.
[0050] Description of reference numerals:
[0051] 1. n+ type SiC substrate; 2. n+ type SiC epitaxial layer; 3. n- type SiC epitaxial layer; 4. p+ type SiC epitaxial layer; 5. Si y N x Passivation protective layer; 6. Anode electrode; 7. Cathode electrode; 8. Back reflection layer. DETAILED DESCRIPTION
[0052] The following is a further detailed description of the embodiments of the present invention in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present invention, but cannot be used to limit the scope of the present invention. The present invention can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
[0053] The following is a detailed description of a method for preparing a high-performance SiC single-photon ultraviolet detector in an embodiment of the present invention.
[0054] See also Figure 1 As shown, Figure 1 The flowchart of the method for preparing a high-performance SiC single-photon ultraviolet detector is schematically shown. The embodiment of the present invention proposes a method for preparing a high-performance SiC single-photon ultraviolet detector, comprising:
[0055] S101 , growing a preset n+ type SiC epitaxial layer 2 on the surface of an 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 n+ type SiC epitaxial layer 2 is preset to be 8-10 μm, and the concentration is 1e16-5e16. The n+ type SiC epitaxial layer 2 is preset to be an n+ functional layer.
[0057] Figure 2 The schematic diagram of growing a preset n+ type SiC epitaxial layer 2 is schematically shown. On the surface of the n+ type SiC substrate 1, a preset n+ type SiC epitaxial layer 2 with a thickness of 8 to 10 μm and a concentration of 1e16 to 5e16 is grown.
[0058] S102 , utilizing the annealing reflow characteristics of alkaline earth doped silicon oxide to prepare spaced hemispherical etching masks on the surface of the preset n+ type SiC epitaxial layer 2 .
[0059] Specifically, utilizing the annealing reflow characteristics of alkaline earth doped silicon oxide, a hemispherical etching mask arranged at intervals is prepared on the surface of the preset n+ type SiC epitaxial layer 2, including:
[0060] Step A1: depositing an alkaline earth doped silicon oxide mask on the preset n+ type SiC epitaxial layer 2.
[0061] Wherein, the thickness of the alkaline earth doped silicon oxide mask is 2000 nm.
[0062] Specifically, Figure 3 The schematic diagram of growing an 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 a preset n+ type SiC epitaxial layer 2 .
[0063] Step A2: using photolithography and etching processes to open windows in the alkaline earth-doped silicon oxide mask.
[0064] Specifically, Figure 4The schematic diagram of opening windows in an alkaline earth doped silicon oxide mask is schematically shown. The alkaline earth doped silicon oxide mask is opened with a window by using photolithography and etching processes. The window pattern is circular and the window radius is 500nm to 1000nm.
[0065] Step A3: The alkaline earth-doped silicon oxide mask after the window is opened is subjected to mask annealing by using a rapid thermal annealing process to form a hemispherical etching mask.
[0066] The radius of the hemispherical etching mask is 500 nm to 1000 nm. The annealing temperature of the rapid thermal annealing process used for the hemispherical etching mask is 1000° C. and the annealing time is 120 seconds.
[0067] Specifically, Figure 5 The schematic diagram of annealing the alkaline earth doped silicon oxide mask is schematically shown. The alkaline earth doped silicon oxide mask after window opening is annealed using a rapid thermal annealing process to form a hemispherical etching mask. The annealing temperature is 1000° C. and the time is 120 seconds.
[0068] S103 , using a hemispherical etching mask, etching the preset n+ type SiC epitaxial layer 2 to obtain an n+ type SiC epitaxial layer 2 .
[0069] The n+ type SiC epitaxial layer 2 has a hemispherical shape.
[0070] The n+ type SiC epitaxial layers 2 are arranged at intervals.
[0071] Specifically, Figure 6 The schematic diagram of etching n+ type SiC epitaxy is schematically shown. Using a hemispherical etching mask as a mask, the preset n+ type SiC epitaxial layer 2 is etched into a hemispherical shape to obtain an n+ type SiC epitaxial layer 2 .
[0072] S104 , epitaxially growing an n− type SiC epitaxial layer 3 and a p+ type SiC epitaxial layer 4 in sequence 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 alternately. The n-type SiC epitaxial layer 3 and the p+ type SiC epitaxial layer 4 are both in a semicircular ring shape. The n-type SiC epitaxial layer 3 is an n-functional layer, and the p+ type SiC epitaxial layer 4 is a p+ functional layer.
[0074] Specifically, Figure 7 Schematically shows a schematic diagram of epitaxial growth of an n-type SiC epitaxial layer 3, Figure 8The schematic diagram of epitaxially growing a p+ type SiC epitaxial layer 4 is schematically shown, and a whole surface of an n- type SiC epitaxial layer 3 and a whole surface of a p+ type SiC epitaxial layer 4 are sequentially epitaxially grown on the surface of an n+ type SiC epitaxial layer 2. The whole surface of the n- type SiC epitaxial layer 3 consists of a semicircular ring-shaped portion and a square-shaped portion.
[0075] It is necessary to etch the square-shaped parts of the entire n-type SiC epitaxial layer 3 and the entire p+ type SiC epitaxial layer 4, that is, to etch the parts between the semicircular ring-shaped n-type SiC epitaxial layers 3 and the parts between the semicircular ring-shaped p+ type SiC epitaxial layers 4.
[0076] S105, growing a preset Si on the surface of the p+ type SiC epitaxial layer 4 and a portion of the surface of the n+ type SiC substrate 1 y N x Passivation protection layer 5.
[0077] Specifically, Fig. 9 Schematic diagram showing the surface passivation of Si y N x Schematic diagram of the passivation protection layer 5, using PECVD, 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), a preset Si y N x Passivation protection layer 5, namely Si y N x Surface passivation anti-reflection layer.
[0078] S106, using photolithography and etching processes, a portion of the surface of the p+ type SiC epitaxial layer 4 is pre-set Si y N x Passivation protection layer 5 is opened to obtain Si y N x Passivation protection layer 5.
[0079] S107, prepare an anode electrode 6 on the surface of a portion of the p+ type SiC epitaxial layer 4, and sequentially prepare a cathode electrode 7 and a back reflection layer 8 on the back side of the n+ type SiC substrate 1 to obtain a high-performance SiC single-photon ultraviolet detector.
[0080] Specifically, Fig.10 Schematically showing a schematic diagram of forming an electrode, Fig.11 The schematic diagram of forming the back reflection layer 8 is schematically shown, see Fig.10 and Fig.11 As shown, an anode electrode 6 is prepared on the surface of a portion of the p+ type SiC epitaxial layer 4, and a cathode electrode 7 and a back reflection layer 8 are sequentially prepared on the back side of the n+ type SiC substrate 1, to obtain a high-performance SiC single-photon ultraviolet detector, including:
[0081] Step B1: After obtaining Si y N x The first Ni metal is deposited on the front and back sides of the entire device of the passivation protection layer 5 .
[0082] The thickness of the first Ni metal is 200 nm.
[0083] Step B2: The first Ni metal is annealed in an inert atmosphere using a rapid thermal annealing process to form a preset anode electrode 6 and a cathode electrode 7 .
[0084] The annealing temperature of the rapid thermal annealing process used for the anode electrode 6 and the cathode electrode 7 is preset to be 1050° C. and the time is 120 seconds.
[0085] Step B3: Clean the preset anode electrode 6 with liquid No. 3 to obtain the anode electrode 6.
[0086] Step B4: Using electron beam evaporation technology, Ti metal, a second Ni metal, and Ag metal are deposited on the back side of the cathode electrode 7 to form a back reflection layer 8 to obtain a high-performance SiC single-photon ultraviolet detector.
[0087] The thickness 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 method that in the embodiment of the present invention, a preset n+ type SiC epitaxial layer 2 is grown on the surface of an n+ type SiC substrate 1; an annealing reflux characteristic of alkaline earth doped silicon oxide is used to prepare a spaced 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 using the hemispherical etching mask to obtain an n+ type SiC epitaxial layer 2, and the shape of the n+ type SiC epitaxial layer 2 is a hemispherical shape; an n- type SiC epitaxial layer 3 and a p+ type SiC epitaxial layer 4 are epitaxially grown in sequence on the surface of the n+ type SiC epitaxial layer 2; a preset Si y N x Passivation protection layer 5; using photolithography and etching processes, the surface of the p+ type SiC epitaxial layer 4 is partially preset Si y N x Passivation protection layer 5 is opened to obtain Si y N xPassivation protection layer 5; an anode electrode 6 is prepared on the surface of a portion of the p+ type SiC epitaxial layer 4, and a cathode electrode 7 and a back reflection layer 8 are sequentially prepared on the back of the n+ type SiC substrate 1 to obtain a high-performance SiC single-photon ultraviolet detector. In this way, the annealing reflux characteristics of alkaline earth doped silicon oxide are used to prepare a three-dimensional hemispherical etching mask. Based on the hemispherical etching mask of the three-dimensional structure, the high-performance SiC single-photon ultraviolet detector finally obtained includes a three-dimensional hemispherical structure. The three-dimensional hemispherical structure can balance the high electric field, and the three high-doping concentration functional layers of the n+ type SiC epitaxial layer 2, the n-type SiC epitaxial layer 3 and the p+ type SiC epitaxial layer 4 can be used to reduce the resistance of the detector to reduce power consumption, and make the detector have a higher operating voltage to achieve a higher detector performance gain.
[0089] Based on the same inventive concept, an embodiment of the present invention also provides a high-performance SiC single-photon ultraviolet detector. Fig.12 : is a schematic diagram of the structure of a high-performance SiC single-photon ultraviolet detector in an embodiment of the present invention. The high-performance SiC single-photon ultraviolet detector may include:
[0090] A back reflection layer 8, a cathode electrode 7 and an n+ type SiC substrate 1 are sequentially arranged from bottom to top;
[0091] n+ type SiC epitaxial layer 2 is formed on the surface of n+ type SiC substrate 1 and arranged at intervals, and the shape of n+ type SiC epitaxial layer 2 is hemispherical;
[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] an anode electrode 6 formed on a surface of a portion of the p+ type SiC epitaxial layer 4;
[0095] Si y N x The passivation protection layer 5 is formed on the surface of part of the p+ type SiC epitaxial layer 4 and in 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 invention uses the annealing reflux characteristics of alkaline 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, and the three-dimensional hemispherical structure can balance the high electric field. Compared with the existing two-dimensional structure, the electric field expansion of the three-dimensional hemispherical structure is slower. Therefore, under the same operating voltage conditions, the three-dimensional hemispherical structure can use a functional layer with a higher doping concentration, thereby reducing the resistance of the device and reducing power consumption, and improving the light response gain of the device. In addition, the electric field expansion of the three-dimensional hemispherical structure is isotropic, without obvious peak electric field, which can avoid terminal design problems. In terms of optical performance, the functional area formed by the three-dimensional hemispherical structure array has an optical management effect of anti-reflection, and no additional optical management structure is required, which greatly reduces the preparation cost of the device. Moreover, the preparation method of the high-performance SiC single-photon ultraviolet detector can be implemented through standard processes, and will not bring additional budgets such as equipment modification to actual production, and can stably produce related products.
[0097] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict.
[0098] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.
Claims
1. A method for preparing a high-performance SiC single-photon ultraviolet detector, characterized in that: include: Growing a preset n+ type SiC epitaxial layer on the surface of the n+ type SiC substrate; Using the annealing reflow characteristics of alkaline earth doped silicon oxide, a spaced hemispherical etching mask is prepared on the surface of the preset n+ type SiC epitaxial layer; Using the hemispherical etching mask, etching the preset n+ type SiC epitaxial layer to obtain an n+ type SiC epitaxial layer, wherein the shape of the n+ type SiC epitaxial layer is a hemispherical shape; epitaxially growing an n-type SiC epitaxial layer and a p+ type SiC epitaxial layer in sequence on the surface of the n+ type SiC epitaxial layer; On the surface of the p+ type SiC epitaxial layer and the surface of part of the n+ type SiC substrate, a preset Si y N x Passivation protective layer; The p+ type SiC epitaxial layer is partially pre-cut using a photolithography process and an etching process. y N x Passivation protection layer is opened to obtain Si y N x Passivation protective layer; An anode electrode is prepared on the surface of a portion of the p+ type SiC epitaxial layer, and a cathode electrode and a back reflection layer are sequentially prepared on the back side of the n+ type SiC substrate to obtain the high performance SiC single photon ultraviolet detector.
2. The method for preparing a high-performance SiC single-photon ultraviolet detector according to claim 1, characterized in that: The method utilizes the annealing reflow characteristics of alkaline earth doped silicon oxide to prepare spaced hemispherical etching masks on the surface of the preset n+ type SiC epitaxial layer, including: Depositing an alkaline earth doped silicon oxide mask on the preset n+ type SiC epitaxial layer; Using the photolithography process and the etching process, opening windows in the alkaline earth doped silicon oxide mask; The alkaline earth doped silicon oxide mask after the window is opened is annealed by using a rapid thermal annealing process to form the hemispherical etching mask.
3. The method for preparing a high-performance SiC single-photon ultraviolet detector according to claim 1, characterized in that: The anode electrode is prepared on the surface of a part of the p+ type SiC epitaxial layer, and the cathode electrode and the back reflection layer are sequentially prepared on the back side of the n+ type SiC substrate to obtain the high performance SiC single photon ultraviolet detector, comprising: In obtaining the Si y N x A first Ni metal is deposited on the front and back sides of the entire device of the passivation protection layer; Annealing the first Ni metal 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 with No. 3 liquid to obtain the anode electrode; By utilizing electron beam evaporation technology, Ti metal, a second Ni metal and Ag metal are deposited on the back of the cathode electrode to form the back reflection layer, thereby obtaining the high-performance SiC single-photon ultraviolet detector.
4. The method for preparing a high-performance SiC single-photon ultraviolet detector according to claim 1, characterized in that: The thickness of the n+ type SiC substrate is 350 μm and the concentration is 5e18.
5. The method for preparing a high-performance SiC single-photon ultraviolet detector according to claim 1, characterized in that: The preset thickness of the n+ type SiC epitaxial layer is 8-10 μm, and the concentration is 1e16-5e16.
6. The method for preparing a high-performance SiC single-photon ultraviolet detector according to claim 2, characterized in that: The thickness of the alkaline earth doped silicon oxide mask is 2000 nm, and the radius of the hemispherical etching mask is 500 nm to 1000 nm.
7. The method for preparing a high-performance SiC single-photon ultraviolet detector according to claim 2, characterized in that: The annealing temperature of the rapid thermal annealing process used for the hemispherical etching mask is 1000° C. and the time is 120 seconds.
8. The method for preparing a high-performance SiC single-photon ultraviolet detector according to claim 3, characterized in that: The annealing temperature of the rapid thermal annealing process used for the preset anode electrode and the cathode electrode is 1050° C. and the time is 120 seconds.
9. The method for preparing a high-performance SiC single-photon ultraviolet detector according to claim 3, characterized in that: The thickness 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.
10. A high performance SiC single photon ultraviolet detector, characterized in that: A method for preparing a high-performance SiC single-photon ultraviolet detector applicable to any one of claims 1 to 9, comprising: A back reflection layer, a cathode electrode and an n+ type SiC substrate are sequentially arranged from bottom to top; n+ type SiC epitaxial layers are formed on the surface of the n+ type SiC substrate and arranged at intervals, and the shape of the n+ type SiC epitaxial layers is a hemispherical shape; An n-type SiC epitaxial layer is formed on the surface of the n+ type SiC epitaxial layer and is in contact with the n+ type SiC substrate; A p+ type SiC epitaxial layer is formed on the surface of the n-type SiC epitaxial layer and is in contact with the n+ type SiC substrate; an anode electrode, formed on a surface of a portion of the p+ type SiC epitaxial layer; Si y N x A passivation protection 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 layers, and is in contact with the anode electrode and the n+ type SiC substrate.
Citation Information
Patent Citations
Ultraviolet detector structure provided with gain and manufacturing method thereof
CN102931272A
Backside illuminated planar SPAD and preparation method thereof
CN115513326A
Avalanche photodiode and its manufacture
JP2000323746A