A flexible low-gain SiC particle detector and a preparation method thereof

Abstract

This invention belongs to the field of semiconductor detector technology, and provides a flexible low-gain SiC particle detector and its fabrication method. The SiC particle detector includes: an N-type doped SiC layer as an N+ gain layer between an N-type active region and a P-type SiC ohmic contact layer; controlling the doping concentration and thickness of the N+ gain layer to achieve a gain of 14-18 times for the SiC particle detector. The fabrication method includes: epitaxially growing an N+ gain layer composed of N-type doped SiC between the N-type active region and the P-type SiC ohmic contact layer; and controlling the doping concentration and thickness of the N+ gain layer to obtain a flexible low-gain SiC particle detector with increased charge collection efficiency and significantly improved signal-to-noise ratio. Furthermore, the use of a mica substrate gives the SiC particle detector excellent bending performance, making it suitable for large-scale curved low-gain SiC particle detectors.

Description

Technical Field

[0001] This invention relates to the field of semiconductor detector technology, and in particular to a flexible low-gain SiC particle detector and its fabrication method. Background Technology

[0002] SiC, as a third-generation semiconductor material, possesses higher bandgap, saturation drift velocity, breakdown electric field, critical displacement energy, and thermal conductivity than Si. Therefore, it is more suitable for detecting the smallest ionized particles under high temperature and high radiation conditions. Furthermore, while Si particle detectors can only operate at low temperatures, SiC particle detectors can be used at room temperature. Low-gain detectors are characterized by internal low-gain avalanche multiplication, which improves detection efficiency and sensitivity while simultaneously increasing the signal-to-noise ratio, thus achieving higher time resolution. Currently, there are no reported studies on low-gain SiC particle detectors. Additionally, for large detectors, their complex structures and numerous curved surfaces are a common challenge. The current common approach is to assemble rigid detectors into curved surfaces, which significantly increases cost and difficulty in both assembly and detector efficiency.

[0003] Therefore, this invention is proposed. Summary of the Invention

[0004] This invention provides a flexible low-gain SiC particle detector and its fabrication method, which addresses the shortcomings of existing SiC particle detectors in low-gain research and the deficiencies of existing rigid detectors in terms of assembly and efficiency when the large detector structure is complex and contains a large number of curved structures, thereby realizing the fabrication of a flexible low-gain SiC particle detector.

[0005] Specifically, the present invention provides a low-gain SiC particle detector, comprising: providing an N-type doped SiC as an N+ gain layer between an N-type active region and a P-type SiC ohmic contact layer, and controlling the doping concentration and thickness of the N+ gain layer to make the gain of the SiC particle detector reach 14 to 18 times.

[0006] According to the low-gain SiC particle detector provided by the present invention, the SiC detector comprises, from bottom to top: a second metal electrode, an N-type SiC ohmic contact layer, an N-type active region, an N+ gain layer, a P-type SiC ohmic contact layer, and a first metal electrode.

[0007] Preferably, the dopant ions of the N+ gain layer are N 3- Its doping concentration is 1×10 16 cm -3 ~1×10 18 cm -3 The thickness is 0.1μm to 1.0μm;

[0008] This invention constructs a thin N+ gain layer between the N-type active region and the P-type ohmic contact region, and this layer is a highly doped N-type layer. This creates a thin high electric field region inside the detector. When charge carriers drift into this high field region, they generate a relatively low multiplication, which improves the charge collection efficiency and the signal-to-noise ratio of the particle detector.

[0009] In this invention, the first metal electrode and the second metal electrode have opposite polarities.

[0010] According to the low-gain SiC particle detector provided by the present invention, an N+ charge control layer is provided between the N-type active region and the N+ gain layer;

[0011] The N+ charge control layer is N-type doped SiC, and the doping ions are N... 3- The doping concentration is 1×10 17 ~4×10 17 cm -3 The thickness is 0.1μm to 0.2μm;

[0012] The N+ gain layer is N-type doped SiC, and the doping ions are N... 3- The doping concentration is 1×10 16 cm -3 ~1×10 17 cm -3 .

[0013] The low-gain SiC particle detector provided by the present invention comprises, from bottom to top: a second metal electrode, an N-type SiC ohmic contact layer, an N-type active region, an N+ gain layer, a P-type SiC ohmic contact layer, and a first metal electrode; the doping concentration of the N+ gain layer is 1×10⁻⁶. 17 cm -3 ~1×10 18 cm -3 Preferably 1×10 17 cm -3 ~4×10 17 cm -3 .

[0014] The low-gain SiC particle detector provided by the present invention is prepared from a mica substrate with a layered structure, and the mica substrate is completely stripped before the SiC particle detector is obtained in order to enable the SiC particle detector to have bending performance.

[0015] Preferably, the radius of curvature of the SiC particle detector is 3–8 mm;

[0016] More preferably, the SiC particle detector can withstand at least 10,000 bending cycles.

[0017] The substrate-free structure of the SiC particle detector of this invention is not subject to the clamping effect of the substrate, thus forming a flexible SiC particle detector. When bent, its radius of curvature can reach 3mm to 8mm, and it can withstand at least 10,000 repeated bends. It can adapt to bends with different curvatures, improve the flexibility of the detector, and save assembly costs.

[0018] According to the low-gain SiC particle detector provided by the present invention, the doped ions in the N-type active region are N 3- The doping concentration is 1×10 13 cm -3 ~1×10 14 cm -3 .

[0019] According to the low-gain SiC particle detector provided by the present invention, the N-type SiC ohmic contact layer is an N-type heavily doped SiC semiconductor material used to realize ohmic contact and carrier transport; and / or, the P-type SiC ohmic contact layer is a P-type heavily doped SiC semiconductor material used to realize ohmic contact and carrier transport.

[0020] Preferably, the doping ions of the N-type SiC ohmic contact layer are N 3- The doping concentration is 5×10 18 cm -3 ~5×10 20 cm -3 ; and / or, the doping ions of the p-type SiC ohmic contact layer are Al 3+ Or B 3+ The doping concentration is 5×10 18 cm -3 ~5×10 20 cm -3 .

[0021] The low-gain SiC particle detector provided by the present invention further includes a passivation layer;

[0022] Preferably, the passivation layer is made of SiO2 and has a thickness of 300nm to 500nm.

[0023] The present invention also provides a method for fabricating a low-gain SiC particle detector as described above, comprising: epitaxially growing an N+ gain layer composed of N-type doped SiC between an N-type active region and a P-type SiC ohmic contact layer, and controlling the doping concentration and thickness of the N+ gain layer.

[0024] Preferably, it includes:

[0025] The substrate is cleaned and dried;

[0026] N-type ohmic contact layer growth;

[0027] N-type active region growth;

[0028] N+ gain layer growth;

[0029] P-type ohmic contact layer growth;

[0030] Fabricate the first metal electrode;

[0031] Fabricate the passivation layer and metal pad;

[0032] Fabricate a second metal electrode.

[0033] The method for fabricating a low-gain SiC particle detector according to the present invention includes:

[0034] Clean and dry the mica substrate;

[0035] N-type ohmic contact layer growth;

[0036] N-type active region growth;

[0037] N+ gain layer growth;

[0038] P-type ohmic contact layer growth;

[0039] Fabricate the first metal electrode;

[0040] Fabricate the passivation layer and metal pad;

[0041] Completely peel off the mica substrate;

[0042] Fabrication of a second metal electrode;

[0043] In this invention, the mica substrate, under the premise of van der Waals (vdW) epitaxy, exhibits strong intralayer interactions and weak interlayer interactions. Due to these weak vdW interlayer interactions, the mica substrate can be completely removed by mechanical peeling and polishing. As a result, the detector structure epitaxially grown on this mica substrate can achieve a substrate-free state, yielding a flexible device.

[0044] The mica substrate can be made of a material with the chemical formula X₂Y. n Z8O 20 The mica sheet shown is (OH,F)4; where X represents an interlayer cation, such as K. + Na + and Ca + One or more of them, where Y represents an octahedral coordination element, such as Al. 3+ Mg 2+ Fe 3 + and Li + One or more of them, where Z represents a tetrahedral coordination element, such as Si. 4+ and / or Al3+ .

[0045] Preferably, the complete stripping is performed by mechanical stripping; mechanical stripping includes using blades, tape, grinding, or other methods to completely remove the mica substrate from the bottom of the entire detector.

[0046] To accommodate SiC particle detectors grown epitaxially, more preferably, the mica substrate is made of fluorophlogopite with the chemical formula KMg3(AlSi3O4). 10 )F2.

[0047] The present invention provides a flexible low-gain SiC particle detector, which uses N-type doped SiC as an N+ gain layer between the N-type active region and the P-type SiC ohmic contact layer. By controlling the doping concentration and thickness of the N+ gain layer, the gain of the SiC particle detector can reach 14 to 18 times, making it very suitable for detecting, tracking and identifying particles such as electrons, protons, neutrons, X-rays, α, β and γ radiation, and MIPs.

[0048] The present invention provides a flexible low-gain SiC particle detector, which is also prepared by a mica substrate with a layered structure. Before obtaining the SiC particle detector, the mica substrate is completely peeled off to give the SiC particle detector excellent bending performance, which is particularly suitable for large curved surface low-gain SiC particle detectors.

[0049] The present invention provides a method for fabricating a flexible low-gain SiC particle detector, which obtains an N+ gain layer composed of N-type doped SiC through epitaxial growth, and controls the doping concentration and thickness of the N+ gain layer to achieve the fabrication of the low-gain SiC particle detector.

[0050] The present invention provides a method for fabricating a flexible low-gain SiC particle detector, which achieves the fabrication of the flexible low-gain SiC particle detector by first growing a detector layer structure on a mica substrate and then completely peeling off the mica. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0052] Figure 1 This is a flowchart illustrating the fabrication process of the flexible low-gain SiC particle detector provided in Embodiment 1 of the present invention;

[0053] Figure 2This is a schematic diagram of the structure of the flexible low-gain SiC particle detector with a mica substrate during the fabrication process provided in Embodiment 1 of the present invention;

[0054] Figure 3 This is a schematic diagram of the mica substrate being peeled off during the fabrication process of the flexible low-gain SiC particle detector provided in Embodiment 1 of the present invention;

[0055] Figure 4 This is a schematic diagram of the structure of the flexible low-gain SiC particle detector after the growth of the second metal electrode, as provided in Embodiment 1 of the present invention.

[0056] Figure 5 This is a schematic diagram of the structure of the flexible low-gain SiC particle detector with a mica substrate during the fabrication process provided in Embodiment 2 of the present invention;

[0057] Figure 6 A schematic diagram of the structure of the flexible low-gain SiC particle detector after the growth of the second metal electrode, provided in Embodiment 2 of the present invention.

[0058] Figure label:

[0059] 1: Mica substrate; 2: N-type ohmic contact layer; 3: N-type active region; 4: N+ charge control layer; 5: N+ gain layer; 6: P-type ohmic contact layer; 7: First metal electrode; 8: Passivation layer; 9: Metal electrode pad layer; 10: Second metal electrode. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0061] The following is combined Figures 1-6 The present invention describes a flexible low-gain SiC particle detector and its fabrication method.

[0062] The present invention provides a low-gain SiC particle detector, comprising: setting an N-type doped SiC as an N+ gain layer between an N-type active region and a P-type SiC ohmic contact layer, and controlling the doping concentration and thickness of the N+ gain layer to make the gain of the SiC particle detector reach 14 to 18 times.

[0063] According to the low-gain SiC particle detector provided by the present invention, the SiC detector comprises, from bottom to top: a second metal electrode, an N-type SiC ohmic contact layer, an N-type active region, an N+ gain layer, a P-type SiC ohmic contact layer, and a first metal electrode.

[0064] Preferably, the dopant ions of the N+ gain layer are N 3- Its doping concentration is 1×10 16 cm -3 ~1×10 18 cm -3 The thickness is 0.1μm to 1.0μm;

[0065] In this invention, the first metal electrode and the second metal electrode have opposite polarities.

[0066] According to the low-gain SiC particle detector provided by the present invention, an N+ charge control layer is provided between the N-type active region and the N+ gain layer;

[0067] The N+ charge control layer is N-type doped SiC, and the doping ions are N... 3- The doping concentration is 1×10 17 ~4×10 17 cm -3 The thickness is 0.1μm to 0.2μm;

[0068] The N+ gain layer is N-type doped SiC, and the doping ions are N... 3- The doping concentration is 1×10 16 cm -3 ~1×10 17 cm -3 .

[0069] The present invention further provides an N+ charge control layer between the N-type active region and the N+ gain layer. This N+ charge control layer can improve the charge collection efficiency and signal-to-noise ratio of the low-gain SiC particle detector of the present invention, while further improving the stability of the low-gain SiC particle detector, such as high-temperature stability.

[0070] The low-gain SiC particle detector provided by the present invention comprises, from bottom to top: a second metal electrode, an N-type SiC ohmic contact layer, an N-type active region, an N+ gain layer, a P-type SiC ohmic contact layer, and a first metal electrode; the doping concentration of the N+ gain layer is 1×10⁻⁶. 17 cm -3 ~1×10 18 cm -3 Preferably 1×10 17 cm -3 ~4×10 17 cm -3 .

[0071] The low-gain SiC particle detector provided by the present invention is prepared from a mica substrate with a layered structure, and the mica substrate is completely stripped before the SiC particle detector is obtained in order to enable the SiC particle detector to have bending performance and present a substrate-free state.

[0072] Preferably, the radius of curvature of the SiC particle detector is 3–8 mm;

[0073] More preferably, the SiC particle detector can withstand at least 10,000 bending cycles.

[0074] The SiC particle detector of this invention forms a "substrate-free" structure, which is not subject to the clamping effect of the substrate, thus forming a flexible SiC particle detector. When bent, its radius of curvature can reach 3mm to 8mm, and it can withstand at least 10,000 repeated bends. It can adapt to bends with different curvatures, improve the flexibility of the detector, and save assembly costs.

[0075] According to the low-gain SiC particle detector provided by the present invention, the doped ions in the N-type active region are N 3- The doping concentration is 1×10 13 cm -3 ~1×10 14 cm -3 .

[0076] According to the low-gain SiC particle detector provided by the present invention, the N-type SiC ohmic contact layer is an N-type heavily doped SiC semiconductor material used to realize ohmic contact and carrier transport; and / or, the P-type SiC ohmic contact layer is a P-type heavily doped SiC semiconductor material used to realize ohmic contact and carrier transport.

[0077] Preferably, the doping ions of the N-type SiC ohmic contact layer are N 3- The doping concentration is 5×10 18 cm -3 ~5×10 20 cm -3 The thickness is 0.3 μm to 0.5 μm; and / or, the doping ions of the p-type SiC ohmic contact layer are Al. 3+ Or B 3+ The doping concentration is 5×10 18 cm -3 ~5×10 20 cm -3 The thickness is 0.3μm to 0.5μm.

[0078] In this invention, uniform doping is preferred in all layers with a silicon carbide structure.

[0079] The low-gain SiC particle detector provided by the present invention further includes a passivation layer;

[0080] Preferably, the passivation layer is made of SiO2 and has a thickness of 300nm to 500nm.

[0081] The present invention also provides a method for fabricating a low-gain SiC particle detector as described above, comprising: epitaxially growing an N+ gain layer composed of N-type doped SiC between an N-type active region and a P-type SiC ohmic contact layer, and controlling the doping concentration and thickness of the N+ gain layer.

[0082] Preferably, it includes:

[0083] The substrate is cleaned and dried;

[0084] N-type ohmic contact layer growth;

[0085] N-type active region growth;

[0086] N+ gain layer growth;

[0087] P-type ohmic contact layer growth;

[0088] Fabricate the first metal electrode;

[0089] Fabricate the passivation layer and metal pad;

[0090] Fabricate a second metal electrode.

[0091] The method for fabricating a low-gain SiC particle detector according to the present invention includes:

[0092] Clean and dry the mica substrate;

[0093] N-type ohmic contact layer growth;

[0094] N-type active region growth;

[0095] N+ gain layer growth;

[0096] P-type ohmic contact layer growth;

[0097] Fabricate the first metal electrode;

[0098] Fabricate the passivation layer and metal pad;

[0099] Completely peel off the mica substrate;

[0100] Fabrication of a second metal electrode;

[0101] In this invention, the mica substrate, under the premise of van der Waals (vdW) epitaxy, exhibits strong intralayer interactions and weak interlayer interactions. Due to this weak vdW interlayer interaction, the mica substrate can be completely removed by mechanical peeling and polishing, thereby enabling the detector structure epitaxially grown on this mica substrate to achieve a "substrate-free" state, resulting in a flexible device.

[0102] The mica substrate can be made of a material with the chemical formula X₂Y. n Z8O 20 The mica sheet shown is (OH,F)4; where X represents an interlayer cation, such as K. + Na + and Ca + One or more of them, where Y represents an octahedral coordination element, such as Al. 3+ Mg 2+ Fe 3+ and Li + One or more of them, where Z represents a tetrahedral coordination element, such as Si. 4+ and / or Al 3+ .

[0103] Preferably, the complete stripping is performed by mechanical stripping; mechanical stripping includes using blades, tape, grinding, or other methods to completely remove the mica substrate from the bottom of the entire detector.

[0104] To accommodate SiC particle detectors grown epitaxially, more preferably, the mica substrate is made of fluorophlogopite with the chemical formula KMg3(AlSi3O4). 10 )F2.

[0105] This invention constructs a thin, heavily doped N-type layer (such as the N+ gain layer in Example 1 below, and the N+ charge control layer and N+ gain layer in Example 2 below) through epitaxial growth between the N-type active region and the P-type ohmic contact region. By controlling the thickness and doping concentration of this layer, a thin, high-electric-field region is generated inside the detector. When charge carriers drift into this high-field region, a relatively low multiplication occurs, with a gain of 14 to 18 times. This results in a larger current signal and improves the signal-to-noise ratio of the particle detector. Furthermore, this invention utilizes mica sheets with a layered structure as the substrate material, enabling the detector to become a flexible detector without rigid substrate constraints. This flexible, low-gain SiC particle detector has a radius of curvature of 3 to 8 mm when bent and can withstand at least 10,000 bends.

[0106] Example 1

[0107] A method for fabricating a flexible, low-gain SiC particle detector, such as... Figures 1-4 As shown, the process is as follows:

[0108] Step 1: Cleaning and drying the mica substrate

[0109] The mica substrate to be cleaned was successively cleaned with acetone, alcohol, and deionized water, and then dried with high-purity nitrogen gas before use. The mica substrate was made of fluorophlogopite.

[0110] Step 2: Growth of N-type ohmic contact layer

[0111] An N-type ohmic contact layer 2 was grown on the aforementioned mica substrate using CVD. This N-type ohmic contact layer is heavily doped with N-type ions. 3- The doping concentration is 5×10 18 cm -3 ~5×10 20 cm -3 The thickness is 0.3μm to 0.5μm.

[0112] Step 3: Growth of N-type active region

[0113] An N-type active region 3 is grown on the aforementioned N-type ohmic contact layer. The N-type active region 3 is N-type doped SiC, and the dopant ions are N. 3- The doping concentration is 1×10 13 cm -3 ~1×10 14 cm -3 The thickness is 45-55 μm, preferably 50 μm.

[0114] Step 4: Growth of N+ gain layer

[0115] An N+ gain layer 5 is epitaxially grown on the aforementioned N-type active region. The N+ gain layer 5 is N-type doped SiC, and the dopant ions are N... 3- The doping concentration is 1×10 17 cm -3 ~4×10 17 cm -3 The thickness is 0.1μm to 1μm.

[0116] Step 5: Growth of P-type ohmic contact layer

[0117] A P-type ohmic contact layer 6, with Al dopant ions, is grown on the aforementioned N+ gain layer. 3+ Or B 3+ The doping concentration is 5×10 18 cm -3 ~5×10 20 cm -3 The thickness is 0.3μm to 0.5μm.

[0118] Step Six: Fabrication of the First Metal Electrode

[0119] A first metal electrode 7 was prepared on top of the aforementioned P-type ohmic contact layer by electron beam evaporation. The material of the electrode was a Ni / Ti / Al alloy, and the thicknesses were 30 nm, 70 nm, and 100 nm, respectively.

[0120] Step 7: Create a passivation layer and metal pad.

[0121] SiO2 is deposited or sputtered on the first metal electrode to form a passivation layer 8 with a thickness of 300 nm to 500 nm;

[0122] A negative stripping photoresist is coated on it, and a metal pad pattern is created by photolithography development; Au metal electrodes with a thickness of 100 nm are sputtered onto it by magnetron sputtering; finally, metal stripping is performed to form metal electrode pad 9.

[0123] Step 8: Peel off the mica substrate

[0124] like Figure 3 As shown, the mica substrate is completely removed from the bottom of the detector using a blade, tape, or grinding, so that the structure on top is in a state without substrate constraints. At this time, the detector can be bent and stretched without being constrained by the substrate.

[0125] Step 9: Fabrication of the second metal electrode

[0126] like Figure 4 As shown, metallic Ni with a thickness of 500 nm is grown by electron beam evaporation at the bottom of the above-mentioned N-type ohmic contact layer, and the polarities of the first metal electrode and the second metal electrode are opposite.

[0127] Example 2

[0128] A method for fabricating a flexible, low-gain SiC particle detector, such as... Figure 5 and 6 As shown, the process is basically the same as in Example 1, except for step four:

[0129] Step 4: Growth of N+ charge control layer and N+ gain layer

[0130] An N+ charge control layer 4 is epitaxially grown first on the aforementioned N-type active region, followed by an N+ gain layer 5. The N+ charge control layer 4 is N-type doped SiC, with N+ doping ions. 3- The doping concentration is 1×10 17 cm -3 ~4×10 17 cm -3 The thickness is 0.1 μm; the N+ gain layer 5 is N-type doped SiC, with N dopant ions. 3- The doping concentration is 1×1016 cm -3 ~1×10 17 cm -3 The thickness is 0.1μm to 1μm.

[0131] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-gain SiC particle detector, characterized in that, include: An N-type doped SiC layer is placed between the N-type active region and the P-type SiC ohmic contact layer as an N+ gain layer. The doping concentration and thickness of the N+ gain layer are controlled to make the gain of the SiC particle detector reach 14 to 18 times. The SiC particle detector comprises, from bottom to top: a second metal electrode, an N-type SiC ohmic contact layer, an N-type active region, an N+ gain layer, a P-type SiC ohmic contact layer, and a first metal electrode; The doped ions of the N+ gain layer are N 3- Its doping concentration is 1×10 16 cm -3 ~1×10 18 cm -3 The thickness is 0.1μm~1.0μm; An N+ charge control layer is provided between the N-type active region and the N+ gain layer; The N+ charge control layer is N-type doped SiC, and the doping ions are N... 3- The doping concentration is 1×10 17 ~4×10 17 cm -3 The thickness is 0.1μm~0.2μm; The N+ gain layer is N-type doped SiC, and the doping ions are N... 3- The doping concentration is 1×10 16 cm -3 ~1×10 17 cm -3 ; The doped ions in the N-type active region are N 3- The doping concentration is 1×10 13 cm -3 ~1×10 14 cm -3 .

2. The low-gain SiC particle detector according to claim 1, characterized in that, The SiC particle detector, from bottom to top, consists of: a second metal electrode, an N-type SiC ohmic contact layer, an N-type active region, an N+ gain layer, a P-type SiC ohmic contact layer, and a first metal electrode; the doping concentration of the N+ gain layer is 1×10⁻⁶. 17 cm -3 ~1×10 18 cm -3 .

3. The low-gain SiC particle detector according to claim 2, characterized in that, The doping concentration of the N+ gain layer is 1×10⁻⁶. 17 cm -3 ~4×10 17 cm -3 .

4. The low-gain SiC particle detector according to any one of claims 1 to 3, characterized in that, It is prepared from a mica substrate with a layered structure, and the mica substrate is completely stripped before the SiC particle detector is obtained to enable the SiC particle detector to have bending properties and present a substrate-free state.

5. The low-gain SiC particle detector according to claim 4, characterized in that, The radius of curvature of the SiC particle detector is 3~8mm.

6. The low-gain SiC particle detector according to claim 5, characterized in that, The SiC particle detector can withstand at least 10,000 bends.

7. The low-gain SiC particle detector according to claim 1, characterized in that, The N-type SiC ohmic contact layer is made of N-type heavily doped SiC semiconductor material to achieve ohmic contact and carrier transport; and / or, the P-type SiC ohmic contact layer is made of P-type heavily doped SiC semiconductor material to achieve ohmic contact and carrier transport.

8. The low-gain SiC particle detector according to claim 7, characterized in that, The doping ions of the N-type SiC ohmic contact layer are N 3- The doping concentration is 5×10 18 cm -3 ~5×10 20 cm -3 ; and / or, the doping ions of the p-type SiC ohmic contact layer are Al 3+ Or B 3+ The doping concentration is 5×10 18 cm -3 ~5×10 20 cm -3 .

9. The low-gain SiC particle detector according to claim 1, characterized in that, It also includes a passivation layer.

10. The low-gain SiC particle detector according to claim 9, characterized in that, The passivation layer is made of SiO2 and has a thickness of 300nm~500nm.

11. The method for fabricating a low-gain SiC particle detector according to any one of claims 1 to 10, characterized in that, include: An N+ gain layer composed of N-type doped SiC is obtained by epitaxial growth between the N-type active region and the P-type SiC ohmic contact layer, and the doping concentration and thickness of the N+ gain layer are controlled. The preparation method includes: The substrate is cleaned and dried; N-type ohmic contact layer growth; N-type active region growth; N+ gain layer growth; P-type ohmic contact layer growth; Fabricate the first metal electrode; Fabricate the passivation layer and metal pad; Fabricate a second metal electrode.

12. The method for fabricating a low-gain SiC particle detector according to claim 11, characterized in that, include: Clean and dry the mica substrate; N-type ohmic contact layer growth; N-type active region growth; N+ gain layer growth; P-type ohmic contact layer growth; Fabricate the first metal electrode; Fabricate the passivation layer and metal pad; Completely peel off the mica substrate; Fabricate a second metal electrode.

13. The method for fabricating a low-gain SiC particle detector according to claim 12, characterized in that, The complete peeling is performed using a mechanical peeling method.

14. The method for fabricating a low-gain SiC particle detector according to claim 13, characterized in that, The mica substrate is made of fluorophlogopite.

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