A trench-type silicon carbide radiation detector with an embedded floating junction and a method for manufacturing the same

Abstract

The application discloses a trench type silicon carbide radiation detector with embedded floating junction and a preparation method thereof, which comprises a substrate, an epitaxial layer arranged on the substrate, a plurality of trenches arranged on a side of the epitaxial layer away from the substrate, a plurality of floating junctions arranged in the epitaxial layer, at least one column of floating junctions and at least one row of floating junctions, at least one column of floating junctions corresponding to adjacent trenches, at least one row of floating junctions corresponding to adjacent trenches, a P+ region arranged on the side of the epitaxial layer away from the substrate and covering a platform region between the trenches and the adjacent trenches, a first electrode arranged on the P+ region and covering the P+ region, and a second electrode arranged on a side of the substrate away from the epitaxial layer and covering the substrate. The application increases the width of the depletion region of the sensitive region due to the introduction of the floating junction and the doped region of the inner wall of the trench, and the electric field in the depletion region can better collect the electron-hole pairs generated by radiation, thereby improving the charge collection efficiency of the detector.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of semiconductor, and particularly relates to a trench type silicon carbide radiation detector with embedded floating junction and a preparation method thereof. BACKGROUND

[0002] In the fields of nuclear medicine, nuclear power plant monitoring, environmental assessment and cosmic ray detection, semiconductor radiation detectors have shown wide application value. Compared with traditional silicon (Si) and germanium (Ge) semiconductor materials, wide bandgap semiconductor silicon carbide (SiC) has unique physical properties, such as wide bandgap, high critical displacement energy, strong critical breakdown field and excellent thermal conductivity, which show significant advantages in the field of radiation detectors. These advantages enable SiC radiation detectors to maintain more stable performance compared to traditional semiconductor devices in extreme working environments such as high temperature and strong radiation environment. SiC radiation detectors have shown good application prospects in detecting and recording high-energy, high-dose radiation particle tracks and their energy distribution.

[0003] Existing detectors usually use Schottky diodes or PiN diodes as their core structure, and the volume of the sensitive region is crucial to improve the detection efficiency. In the case of fixed detector surface area, in order to ensure that the carriers generated by radiation can be effectively collected, the thickness of the sensitive region needs to be reasonably designed according to the penetration depth of the radiation particles in the material. In particular, for high-energy radiation particles with a large energy deposition distance, a thicker sensitive region needs to be designed to cope with it. However, for high-energy particle radiation detection, even if the sensitive region is designed to be thick enough, a large reverse bias voltage still needs to be applied to achieve complete depletion of the sensitive region, which results in a high electric field strength at the surface and junction region of the detector, thereby increasing the risk of leakage noise of the detector. In addition, the single i-region design also makes the electric field distribution in the sensitive region uneven, which is not conducive to the effective separation and collection of the carriers generated by radiation.

[0004] Therefore, how to design the i-region structure of the device to improve the performance of the device has become a problem to be solved. SUMMARY

[0005] In order to solve the above problems existing in the prior art, the present application provides a trench type silicon carbide radiation detector with embedded floating junction and a preparation method thereof. The technical problem to be solved by the present application is solved by the following technical scheme:

[0006] In the first aspect, the present application provides a trench type silicon carbide radiation detector with embedded floating junction, comprising:

[0007] a substrate;

[0008] An epitaxial layer is disposed on the substrate, and a plurality of trenches are disposed on the side of the epitaxial layer away from the substrate, a plurality of floating junctions are disposed in the epitaxial layer, at least one column of floating junctions is arranged in the direction parallel to the substrate, and at least one row of floating junctions is arranged in the direction perpendicular to the substrate; at least one column of floating junctions is arranged between adjacent trenches in the direction parallel to the substrate, and at least one row of floating junctions is arranged between adjacent trenches in the direction perpendicular to the substrate;

[0009] A P+ region is disposed on the side of the epitaxial layer away from the substrate and covers the platform region between the trenches and the adjacent trenches.

[0010] A first electrode is disposed on the P+ region and covers the P+ region.

[0011] A second electrode is disposed on the side of the substrate away from the epitaxial layer and covers the substrate.

[0012] In a second aspect, the application further provides a preparation method of the trench-type silicon carbide radiation detector with embedded floating junctions, comprising:

[0013] A substrate is provided.

[0014] An epitaxial layer is epitaxially grown on the substrate, a plurality of floating junctions are formed in the epitaxial layer by ion implantation, at least one column of floating junctions is arranged in the direction parallel to the substrate, and at least one row of floating junctions is arranged in the direction perpendicular to the substrate; a plurality of trenches are etched on the side of the epitaxial layer away from the substrate; at least one column of floating junctions is arranged between adjacent trenches in the direction parallel to the substrate, and at least one row of floating junctions is arranged between adjacent trenches in the direction perpendicular to the substrate.

[0015] A P+ region is formed on the side of the epitaxial layer away from the substrate by ion implantation.

[0016] A first electrode is formed by sputtering metal on the surface of the P+ region.

[0017] A second electrode is formed by sputtering metal on the surface of the side of the substrate away from the epitaxial layer.

[0018] The application has the following beneficial effects:

[0019] The application provides a trench type silicon carbide radiation detector with embedded floating junction and a preparation method thereof.

[0020] The application will be further described in detail below with reference to the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 Fig. 1 is a schematic diagram of a trench type silicon carbide radiation detector with embedded floating junction provided by an embodiment of the application;

[0022] Figure 2 Fig. 2 is a schematic diagram of a trench type silicon carbide radiation detector with embedded floating junction provided by an embodiment of the application;

[0023] Figure 3 Fig. 3 is a schematic diagram of a simulation cell of a trench type silicon carbide radiation detector with embedded floating junction provided by an embodiment of the application;

[0024] Figure 4 Fig. 4 is a schematic diagram of a simulation experiment effect provided by an embodiment of the application;

[0025] Figures 5a to 5o Fig. 5 is a schematic diagram of a preparation process of a trench type silicon carbide radiation detector with embedded floating junction provided by an embodiment of the application. DETAILED DESCRIPTION

[0026] The application will be further described in detail below with reference to the drawings and examples.

[0027] Compared with silicon (Si) based radiation detectors, silicon carbide (SiC) based radiation detectors exhibit more excellent anti-radiation capability and lower leakage current characteristics, which is crucial for the demand of high reliability radiation detectors in the field of national defense and medical treatment. In order to cope with the challenges of improving detection efficiency, reducing parasitic capacitance, tolerating high radiation environment, optimizing current density distribution and enhancing energy resolution, the present application proposes a trench type silicon carbide radiation detector embedded with floating junction. On the basis of the traditional Schottky or PiN structure, a trench structure is ingeniously introduced above the N-epitaxial layer of the device, and a layer of region different from the doping type of the sensitive region is formed on the sidewall and bottom of the trench. By introducing this layer of different doped region, the detection efficiency of the device is positively affected.

[0028] Please refer to Figure 1 , Figure 1 is a schematic diagram of a trench type silicon carbide radiation detector embedded with floating junction provided by the embodiments of the present application. The trench type silicon carbide radiation detector embedded with floating junction provided by the present application comprises:

[0029] a substrate 10;

[0030] an epitaxial layer 20 arranged on the substrate 10, the side of the epitaxial layer 20 away from the substrate 10 is provided with a plurality of trenches 30, and the epitaxial layer 20 is provided with a plurality of floating junctions 40, at least one column of floating junctions 40 is arranged along the direction D1 parallel to the substrate, and at least one row of floating junctions 40 is arranged along the direction D2 perpendicular to the substrate; along the direction D1 parallel to the substrate, at least one column of floating junctions 40 corresponds between adjacent trenches 30, and along the direction D2 perpendicular to the substrate, at least one row of floating junctions 40 corresponds between adjacent trenches 30;

[0031] a P+ region 50 arranged on the side of the epitaxial layer 20 away from the substrate 10, covering the platform region 60 between the trenches 30 and the adjacent trenches 30;

[0032] a first electrode 70 arranged on the P+ region 50, covering the P+ region 50;

[0033] a second electrode 80 arranged on the side of the substrate 10 away from the epitaxial layer 20, covering the substrate 10.

[0034] Specifically, please continue to refer to Figure 1The trench type silicon carbide radiation detector with embedded floating junction provided by the embodiment comprises a substrate 10 and an epitaxial layer 20 arranged in layers, a plurality of floating junctions 40 are arranged in the epitaxial layer 20, a plurality of trenches 30 are arranged on the side of the epitaxial layer 20 away from the substrate 10, the trenches 30 extend to the upper side of the floating junctions 40, a P+ region 50 is arranged on the platform area 60 in the trench 30 and between adjacent trenches 30, a first electrode 70 is arranged on the P+ region 50, and a second electrode 80 is arranged on the side of the substrate 10 away from the epitaxial layer 20; in this way, the trenches 30 are introduced on the upper surface of the epitaxial layer 20, the P+ region 50 is arranged in the trenches 30, the P region is introduced in the epitaxial layer 20, the overall electric field distribution is changed, the electric field is more uniform, and the uniform electric field promotes the charge collection efficiency; the epitaxial region is provided with a plurality of floating junctions 40, and the P+ region is further arranged in the trench, so that the width of the depletion region in the epitaxial region is increased, the electric field in the depletion region can better collect the electron-hole pairs generated by radiation, improve the collection efficiency, and reduce the influence of radiation damage on the performance of the detector; in addition, the introduction of the trench 30 structure changes the original planar structure of the device into a trench type device, increases the contact area between the conversion material on the surface of the device and the device, and thus more secondary ions enter the device and are collected.

[0035] It should be noted that, Figure 1 The embodiments shown only show the positional relationship of each film layer in the device, and do not represent the actual size.

[0036] In an optional embodiment of the present application, the substrate 10 is a SiC substrate (Sub), the epitaxial layer 20 is a SiC epitaxial layer, the substrate 10 and the epitaxial layer 20 have the same doping type, the substrate 10 is heavily doped, the epitaxial layer 20 is lightly doped, and the doping concentration of the substrate 10 is higher than that of the epitaxial layer 20.

[0037] The thickness of the SiC substrate 10 is 20 μm, the width is 40 μm, the doping type is N type, the doping concentration is 5*10 18 cm -3 ~8*10 18 cm -3 , and the doping ions include but are not limited to nitrogen ions and phosphorus ions; the epitaxial layer 20 is arranged above the substrate 10, the doping concentration ranges from 1*10 14 cm -3 ~5*10 14 cm -3 , the thickness is 20-100 μm, the width is 40 μm, the doping ions include but are not limited to nitrogen ions and phosphorus ions, and an N-drift region is formed.

[0038] In an alternative embodiment of the present application, along the direction D1 parallel to the substrate, 1-4 columns of floating junctions 40 are arranged between adjacent grooves 30, and the distance between two adjacent columns of floating junctions 40 is 0-10 μm.

[0039] In an alternative embodiment of the present application, along the direction D2 perpendicular to the substrate, 1-6 rows of floating junctions 40 are arranged between adjacent grooves 30, and the distance between two adjacent rows of floating junctions 40 is 10-20 μm.

[0040] In an alternative embodiment of the present application, along the direction D1 parallel to the substrate, the width of the floating junction 40 is 1-9 μm; along the direction D2 perpendicular to the substrate, the thickness of the floating junction 40 is 0.2-1.8 μm; the doping concentration of the floating junction 40 is 1×10 15 cm -3 -1×10 17 cm -3 , and the doping ions of the floating junction 40 include boron ions.

[0041] Specifically, in the present embodiment, the doping concentration of the floating junction 40 is 1×10 15 cm -3 -1×10 17 cm -3 , the doping ions of the floating junction 40 include boron ions, forming a P-type floating junction. Optionally, the floating junction 40 is rectangular, and can also be trapezoidal, square, elliptical or circular, which is not limited in the present embodiment. Optionally, the width of the floating junction 40 can be 2, 3, 4, 5, 6, 7, 8 μm, and the thickness of the floating junction 40 can be 0.4, 0.6, 0.8, 1, 1.2, 1.4, 1.6 μm.

[0042] In an alternative embodiment of the present application, along the direction D1 parallel to the substrate, the width of the groove 30 is 5-15 μm, and the width of the platform region 60 between adjacent grooves 30 is 5-15 μm; along the direction D2 perpendicular to the substrate, the depth of the groove 30 is 10-90 μm.

[0043] Specifically, in the present embodiment, the groove 30 extends into the epitaxial layer 20, and the width of the groove 30 can be 8, 10, 12, 14 μm, the depth of the groove 30 can be 20, 30, 40, 50, 60, 70, 80 μm, and the width of the platform region 60 between adjacent grooves 30 can be 7, 8, 9, 10, 12, 13, 14 μm.

[0044] Optionally, the trench 30 can be filled with a conversion material, including but not limited to lithium fluoride (LiF). For example, in a 45 μm sensitive region thickness detecting 14 MeV neutrons, the trench 30 has a width of 5 μm and a depth of 10 μm. Embedding 1 row of floating junctions 40 in the epitaxial layer 20 μm thickness makes the irradiated detector work at a voltage 50% lower than the conventional detector structure while reaching 100% charge collection efficiency, and 30% lower than the irradiated detector embedded with only floating junctions 40. The number of rows of floating junctions 40 in the sensitive region is related to the thickness of the sensitive region and the depth of the trench 30. For example, in a 100 μm sensitive region thickness detecting 14 MeV neutrons, the trench 30 has a depth of 10 μm, embedding 1-6 rows of floating junctions 40 in the epitaxial layer 20 μm thickness can improve the sensitive region volume and detection efficiency compared with the conventional structure, and the detection efficiency increases with the number of rows of floating junctions 40 at the same working voltage.

[0045] In an optional embodiment of the present application, the thickness of the P+ region 50 covering the side wall and bottom of the trench 30 is greater than the thickness of the P+ region 50 covering the platform region 60 between adjacent trenches 30.

[0046] In an optional embodiment of the present application, the thickness of the P+ region 50 covering the side wall and bottom of the trench 30 is 0.5-5 μm, and the P+ region 50 covering the side wall and bottom of the trench 30 forms a P region; the thickness of the P+ region 50 covering the platform region 60 between adjacent trenches 30 is 0.3-0.6 μm, and the material of the P+ region 50 is SiC.

[0047] In particular, in this embodiment, the P+ region 50 is provided in the trench 30 and the platform region 60 between adjacent trenches 30, and the thickness of the P+ region 50 in the two places is different, i.e., the thickness of the P+ region 50 covering the trench 30 is greater than the thickness of the P+ region 50 on the platform region 60 between adjacent trenches 30. In this way, the P region in the trench 30 as a P column changes the overall electric field distribution of the device, so that the electric field is more uniform, and the uniform electric field improves the charge collection efficiency. In addition, the floating junction 40 provided in the epitaxial region in combination with the P column in the trench 30 increases the width of the depletion region of the sensitive region, and the electric field in the depletion region makes the electron-hole pairs generated by irradiation be better collected, thereby improving the charge collection efficiency.

[0048] In an optional embodiment of the present application, the doping concentration of the P+ region 50 is 5×10 18 cm -3 -2×10 19 cm -3 , and the doping ions of the P+ region 50 include boron ions.

[0049] In an optional embodiment of the present invention, the floating junctions 40 are arranged in an array within the epitaxial layer 20. Alternatively, the floating junctions 40 are arranged in multiple columns and rows in an array arrangement. In this way, the floating junctions 40 are evenly arranged, which can simplify the process.

[0050] In an optional embodiment of the present invention, see Figure 2 , Figure 2 This is another schematic diagram of a trench-type silicon carbide irradiation detector with an embedded floating junction provided by an embodiment of the present invention. Along the direction D1 parallel to the substrate, the distance between the floating junctions 40 below the platform area 60 between adjacent trenches 30 is smaller than the distance between the floating junctions 40 below the trenches 30; the spacing between the floating junctions 40 below the platform area 60 is small, that is, the density of the floating junctions 40 below the platform area 60 is high, which is conducive to the connection and expansion of the depletion region, thereby improving the charge collection efficiency.

[0051] It should be noted that Figure 2 The illustrated embodiment only schematically shows a schematic diagram of four columns and two rows of floating junctions corresponding to adjacent trenches, and the distance between adjacent floating junctions does not represent the actual size.

[0052] In an optional embodiment of the present invention, the first electrode 70 is an anode, which is an ohmic contact electrode, and the material includes but is not limited to Ni material; the second electrode 80 is a cathode, which is an ohmic contact electrode, and the material includes but is not limited to Ni material.

[0053] In an optional embodiment of the present invention, see Figure 3 , Figure 3 This is a schematic diagram of a simulation cell of a trench-type silicon carbide radiation detector with an embedded floating junction provided by an embodiment of the present invention. The trench-type silicon carbide radiation detector device with an embedded floating junction based on this embodiment was simulated and verified using Sentaurus TCAD software.

[0054] 1. Simulation structure

[0055] The silicon carbide substrate 10 has a thickness of 20 μm, a width of 20 μm, an N-type doping type, and a doping concentration of 5×10 18 cm -3 .

[0056] The silicon carbide epitaxial layer 20 has a thickness of 44.5 μm, a width of 20 μm, an N-type doping type, and a doping concentration of 3×10 14 cm -3P-type doping is performed at a height of 20 μm on the epitaxial layer 20 to form two floating junctions 40. Each floating junction 40 has a width of 5 μm, a thickness of 1 μm, and a doping concentration of 1.5×10 16 cm -3 .

[0057] The groove 30 has a width of 5 μm and a depth of 10 μm.

[0058] The silicon carbide P+ region 50 has a thickness of 0.5 μm, a P-type doping type, and a doping concentration of 1.05×10 19 cm -3 .

[0059] The anode is made of Ni material and is located above the P+ region 50 with a thickness of 0.2 μm-1 μm.

[0060] The cathode is made of Ni material and is located below the substrate 10 with a thickness of 0.2 μm-1 μm.

[0061] 2. Simulation Results

[0062] like Figure 4 As shown, Figure 4 It is a schematic diagram of the simulation experiment effect provided by an embodiment of the present invention, showing the charge collection efficiency (CCE) variation with voltage of the combination of setting a floating junction 40 in the epitaxial layer 20 and setting a trench 30 on one side of the epitaxial layer 20 (TPIN-FJ-W5-H10), the charge collection efficiency (CCE) variation with voltage of a single floating junction 40 structure (PIN-FJ), and the charge collection efficiency (CCE) variation with voltage of a single trench 30 structure (TPIN-W5H10). In comparison, the scheme of the present invention of setting a floating junction 40 in the epitaxial layer 20 and setting a trench 30 on one side of the epitaxial layer 20, and setting a P+ region 50 inside the trench 30, can increase the depletion region width of the sensitive region, and the electric field inside the depletion region will better collect the electron-hole pairs generated by irradiation, thereby improving the charge collection efficiency.

[0063] Based on the same inventive concept, the present invention further provides a method for preparing a trench-type silicon carbide radiation detector with an embedded floating junction, which is used to prepare the detector provided by the above embodiment of the present invention. The embodiment of the detector is referred to above and will not be described in detail here. The preparation method comprises:

[0064] Providing a substrate 10;

[0065] forming a plurality of floating junctions 40 in the epitaxial layer 20 by means of ion implantation; forming a plurality of trenches 30 on the side of the epitaxial layer 20 away from the substrate 10; corresponding to at least one column of floating junctions 40 between adjacent trenches 30 in the direction D1 parallel to the substrate, and corresponding to at least one row of floating junctions 40 between adjacent trenches 30 in the direction D2 perpendicular to the substrate;

[0066] forming a P+ region 50 in the epitaxial layer 20 by means of ion implantation on the side of the epitaxial layer 20 away from the substrate 10;

[0067] sputtering a metal on the P+ region 50 to form a first electrode 70;

[0068] sputtering a metal on the surface of the substrate 10 away from the epitaxial layer 20 to form a second electrode 80.

[0069] In an alternative embodiment of the present application, an epitaxial layer 20 is grown on a substrate 10, and a plurality of floating junctions 40 are formed in the epitaxial layer 20 by means of ion implantation; a plurality of trenches 30 are formed on the side of the epitaxial layer 20 away from the substrate 10, including:

[0070] growing a first epitaxial layer on the substrate 10, and depositing a first silicon dioxide layer on the first epitaxial layer;

[0071] coating a photoresist on the first silicon dioxide layer, and forming a first photoresist etching mask through exposure, development, post-baking and UV curing; etching the first silicon dioxide layer according to the first photoresist etching mask to form a first implantation window;

[0072] removing the first photoresist etching mask on the first silicon dioxide layer, and performing ion implantation at the first implantation window to form a floating junction 40;

[0073] removing the first silicon dioxide layer remaining on the first epitaxial layer, and growing a second epitaxial layer on the first epitaxial layer; wherein the first epitaxial layer and the second epitaxial layer have the same doping type and doping concentration;

[0074] depositing a second silicon dioxide layer on the second epitaxial layer;

[0075] coating a photoresist on the second silicon dioxide layer, and forming a second photoresist etching mask through exposure, development, post-baking and UV curing; etching the second silicon dioxide layer according to the second photoresist etching mask, removing the second photoresist etching mask on the second silicon dioxide layer, and etching the second epitaxial layer to form a trench 30 using the remaining second silicon dioxide layer as an etching mask.

[0076] In an alternative embodiment of the present application, the preparation of the trench type silicon carbide irradiation detector with embedded floating junction is realized by the following process, specifically:

[0077] S101, RCA cleaning is performed on the provided N+ type semiconductor substrate to form an N+ substrate.

[0078] S102, epitaxial growth of a first epitaxial layer to the floating junction position on the substrate layer, the ion doping type of the first epitaxial layer is the same as the doping type of the substrate, and the substrate layer is heavily doped, the first epitaxial layer is lightly doped, and the ion doping concentration of the substrate layer is higher than that of the first epitaxial layer, as shown in Figure 5a .

[0079] S103, depositing a first silicon dioxide layer on the first epitaxial layer; specifically, depositing a first silicon dioxide layer on the first epitaxial layer by plasma enhanced chemical vapor deposition (PECVD), as shown in Figure 5b .

[0080] S104, forming a first photoresist (PR) etching mask on the surface of the first silicon dioxide layer; coating photoresist on the surface of the first silicon dioxide layer, and after exposure, development, post-baking and UV solidification, forming a first photoresist (PR) etching mask on the surface of the first silicon dioxide layer, as shown in Figure 5c .

[0081] S105, etching the first silicon dioxide layer according to the first photoresist etching mask to form a first implantation window; using ICP or RIE plasma dry etching to etch the first silicon dioxide layer, so that the two sides of the etched area of the first silicon dioxide layer are steep and vertically aligned with the two sides of the first photoresist etching mask, as shown in Figure 5d .

[0082] S106, removing the first photoresist etching mask above the first silicon dioxide layer; performing first ion implantation in the first implantation window to form a floating junction; removing the first silicon dioxide layer and high-temperature annealing, as shown in Figure 5e and 5f .

[0083] S107, continuing to epitaxially grow a second epitaxial layer on the first epitaxial layer, the doping type and doping concentration of the first epitaxial layer and the second epitaxial layer are the same, and the first epitaxial layer and the second epitaxial layer jointly form an epitaxial layer, as shown in Figure 5g .

[0084] S108, depositing a second silicon dioxide layer on the second epitaxial layer; coating a photoresist on the second silicon dioxide layer, and performing exposure, development, post-baking and UV solidification to form a second photoresist etching mask; etching the second silicon dioxide layer according to the second photoresist etching mask, removing the second photoresist etching mask on the second silicon dioxide layer, taking the remaining second silicon dioxide layer as an etching mask, and etching the second epitaxial layer by ICP to form a trench, as shown in Figures 5h to 5l .

[0085] S109, performing ion implantation on the sidewall of the trench to form a P+ layer covering the sidewall and bottom of the trench, and removing the second silicon dioxide layer, as shown in Figure 5m .

[0086] S110, performing ion implantation on the platform area between adjacent trenches to form a P+ layer covering the platform area, and performing high-temperature annealing, as shown in Figure 5n .

[0087] S111, sputtering metal on the upper surface of the P+ area and the lower surface of the substrate layer to form an ohmic contact anode and an ohmic contact cathode, respectively, as shown in Figure 5o .

[0088] It should be noted that the relational terms such as first and second, and the like, are used only to differentiate one entity or operation from another, and do not necessarily require or imply that these entities or operations exist in any actual relationship or order. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that an article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed. Without more limitations, the element defined by the statement "including a" does not exclude the presence of additional identical elements in the article or device including the element. The terms "connected" or "connected" and the like are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0089] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific feature or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In the specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features or characteristics described can be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in the specification.

[0090] The above is a further detailed description of the present application in combination with specific preferred embodiments, and cannot be considered as limiting the specific implementation of the present application to these descriptions. For those skilled in the art, without departing from the concept of the present application, a number of simple deductions or substitutions can be made, which should be considered as falling within the protection scope of the present application.

Claims

1. A trench-type silicon carbide radiation detector with an embedded floating junction, characterized in that: include: substrate; An epitaxial layer is provided on the substrate, a plurality of trenches are provided on a side of the epitaxial layer facing away from the substrate, a plurality of floating junctions are provided in the epitaxial layer, at least one column of the floating junctions is provided in a direction parallel to the substrate, and at least one row of the floating junctions is provided in a direction perpendicular to the substrate; Along a direction parallel to the substrate, adjacent grooves correspond to at least one column of floating junctions, and along a direction perpendicular to the substrate, adjacent grooves correspond to at least one row of floating junctions; A P+ region is provided on a side of the epitaxial layer facing away from the substrate and covers the platform region between the trench and the adjacent trench; A first electrode is disposed on the P+ region and covers the P+ region; The second electrode is arranged on a side of the substrate away from the epitaxial layer and covers the substrate.

2. The trench-type silicon carbide radiation detector with embedded floating junction according to claim 1, characterized in that: Along a direction parallel to the substrate, 1 to 4 columns of floating junctions are correspondingly arranged between adjacent grooves, and a distance between two adjacent columns of floating junctions is 0 μm to 10 μm.

3. The trench-type silicon carbide radiation detector with embedded floating junction according to claim 1, characterized in that: Along a direction perpendicular to the substrate, 1 to 6 rows of floating junctions are correspondingly arranged between adjacent grooves, and a distance between two adjacent rows of floating junctions is 10 μm to 20 μm.

4. The trench-type silicon carbide radiation detector with embedded floating junction according to claim 1, characterized in that: The floating junction array is arranged in the epitaxial layer.

5. The trench-type silicon carbide radiation detector with embedded floating junction according to claim 1, characterized in that: Along a direction parallel to the substrate, a distance between the floating junctions located under the mesa region between adjacent trenches is smaller than a distance between the floating junctions located under the trenches.

6. The trench-type silicon carbide radiation detector with embedded floating junction according to claim 1, characterized in that: The width of the floating junction is 1 μm to 9 μm in a direction parallel to the substrate; the thickness of the floating junction is 0.2 μm to 1.8 μm in a direction perpendicular to the substrate; and the doping concentration of the floating junction is 1×10 15 cm -3 ~1×10 17 cm -3 , the doping ions of the floating junction include boron ions.

7. The trench-type silicon carbide radiation detector with embedded floating junction according to claim 1, characterized in that: Along the direction parallel to the substrate, the groove width is 5 μm to 15 μm, and the platform area width between adjacent grooves is 5 μm to 15 μm; along the direction perpendicular to the substrate, the groove depth is 10 μm to 90 μm.

8. The trench-type silicon carbide radiation detector with embedded floating junction according to claim 1, characterized in that: The thickness of the P+ region covering the sidewalls and bottom of the trench is greater than the thickness of the P+ region covering the terrace region between adjacent trenches; The thickness of the P+ region covering the sidewalls and bottom of the trench is 0.5 μm to 5 μm, and the P+ region covering the sidewalls and bottom of the trench forms a P region; the thickness of the P+ region covering the platform area between adjacent trenches is 0.3 μm to 0.6 μm.

9. A method for preparing a trench-type silicon carbide radiation detector with an embedded floating junction, characterized in that: include: providing a substrate; Epitaxially growing an epitaxial layer on the substrate, forming a plurality of floating junctions in the epitaxial layer by ion implantation, wherein at least one column of the floating junctions is arranged along a direction parallel to the substrate, and at least one row of the floating junctions is arranged along a direction perpendicular to the substrate; Etching a plurality of grooves on a side of the epitaxial layer facing away from the substrate; Along a direction parallel to the substrate, at least one column of floating junctions corresponds to each other between adjacent trenches; along a direction perpendicular to the substrate, at least one row of floating junctions corresponds to each other between adjacent trenches; forming a P+ region on a side of the epitaxial layer facing away from the substrate by ion implantation; sputtering metal on the upper surface of the P+ region to form a first electrode; A second electrode is formed by sputtering metal on a surface of the substrate facing away from the epitaxial layer.

10. The method for preparing a trench-type silicon carbide radiation detector with embedded floating junction according to claim 9, characterized in that: epitaxially growing an epitaxial layer on the substrate, and forming a plurality of floating junctions in the epitaxial layer by ion implantation; Etching a plurality of trenches on a side of the epitaxial layer facing away from the substrate, comprising: epitaxially growing a first epitaxial layer on the substrate, and depositing a first silicon dioxide layer on the first epitaxial layer; Coating photoresist on the first silicon dioxide layer, exposing, developing, post-baking, and UV curing to form a first photoresist etching mask; etching the first silicon dioxide layer according to the first photoresist etching mask to form a first injection window; removing the first photoresist etching mask on the first silicon dioxide layer, and performing ion implantation in the first implantation window to form the floating junction; Removing the first silicon dioxide layer remaining on the first epitaxial layer, and epitaxially growing a second epitaxial layer on the first epitaxial layer; wherein the first epitaxial layer and the second epitaxial layer have the same doping type and doping concentration; depositing a second silicon dioxide layer on the second epitaxial layer; A photoresist is coated on the second silicon dioxide layer, and after exposure, development, post-baking, and UV curing, a second photoresist etching mask is formed; the second silicon dioxide layer is etched according to the second photoresist etching mask, the second photoresist etching mask on the second silicon dioxide layer is removed, and the remaining second silicon dioxide layer is used as an etching mask to etch the second epitaxial layer to form a groove.

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