A wide-spectrum response PIN high-temperature ultraviolet detector and its preparation method

Abstract

The present invention discloses a wide-spectrum-response PIN high-temperature ultraviolet detector, belonging to the field of microelectronics. The detector comprises a 4H-SiC substrate, a 4H-SiC epitaxial layer disposed on the 4H-SiC substrate, a 4H-SiC absorption layer and a β-Ga2O3 absorption layer disposed on the left and right sides of the upper surface of the 4H-SiC epitaxial layer, a 4H-SiC contact layer disposed on the 4H-SiC absorption layer, and a β-Ga2O3 contact layer disposed on the β-Ga2O3 absorption layer. A left-half tilted mesa structure is formed on the left side of the 4H-SiC contact layer, the 4H-SiC absorption layer, and the 4H-SiC epitaxial layer; a right-half tilted mesa structure is formed on the right side of the β-Ga2O3 contact layer, the β-Ga2O3 absorption layer, and the 4H-SiC epitaxial layer; and N / P-type ohmic contact metals are disposed on the upper and lower mesas of the tilted mesa structure, respectively. The detector has a strong light response capability and a wide detection wavelength range.

Description

Technical Field

[0001] The invention belongs to the technical field of microelectronics, and in particular relates to a wide-spectrum-response PIN high-temperature ultraviolet detector and a preparation method thereof. Background Art

[0002] Ultraviolet photodetectors are devices that convert ultraviolet light signals into electrical signals. They have a wide range of applications in weather monitoring, fire alarms, space exploration, cell detection, and ultraviolet radiation measurement, and possess significant civilian and defense value. Compared to silicon-based devices, which are widely used in long-wavelength photodetectors, wide-bandgap semiconductors offer unparalleled advantages in ultraviolet detection. The most obvious advantage is their inherent blindness to visible light and sunlight, which eliminates the costly addition of optical filtering equipment. Furthermore, the gradual optimization and advancement of wide-bandgap semiconductor material growth equipment and conditions, as well as continuous breakthroughs in growth technology, have fueled the development and advancement of wide-bandgap ultraviolet detection.

[0003] Due to their excellent material properties, SiC-based semiconductor devices play an important role in high-temperature applications. Currently, common high-temperature UV detectors are mainly photodiodes, including SBD (Schottky Barrier Diode), pn junction, pin, and APD (Avalanche Photon Diode) types. Among them, SBD-type detectors have high leakage current, pn junction types have low light utilization, and APD types have excessively high noise. Pin-type detectors, on the other hand, help reduce device power consumption and high-temperature dark current, making them suitable for high-temperature applications.

[0004] However, existing PIN-type ultraviolet detectors usually use a single material (such as 4H-SiC) as the light absorption layer, resulting in a single photoelectric response peak and a narrow spectral response range, which cannot simultaneously meet the requirements of shorter wavelength light detection. Summary of the Invention

[0005] To address the low gain, low responsivity, and narrow detection wavelength range issues of existing 4H-SiC single-material UV photodetectors, the present invention provides a wide-spectrum-response PIN high-temperature UV detector and a method for preparing it. The technical problems to be solved by the present invention are achieved through the following technical solutions:

[0006] In a first aspect, the present invention proposes a wide-spectrum response PIN high-temperature ultraviolet detector, comprising a 4H-SiC substrate, a 4H-SiC epitaxial layer, a 4H-SiC absorption layer, a β-Ga2O3 absorption layer, a 4H-SiC contact layer, a β-Ga2O3 contact layer, a passivation layer, an N-type ohmic contact metal, and a P-type ohmic contact metal; wherein,

[0007] The 4H-SiC epitaxial layer is provided on the 4H-SiC substrate;

[0008] The 4H-SiC absorption layer is arranged on the upper left of the 4H-SiC epitaxial layer; the β-Ga2O3 absorption layer has the same height as the 4H-SiC absorption layer and is arranged adjacent to the 4H-SiC absorption layer and on the upper right of the 4H-SiC epitaxial layer;

[0009] The 4H-SiC contact layer is disposed above the 4H-SiC absorption layer and is aligned with the right side of the 4H-SiC absorption layer; the β-Ga2O3 contact layer is disposed above the β-Ga2O3 absorption layer and is aligned with the left side of the β-Ga2O3 absorption layer; and the β-Ga2O3 contact layer and the 4H-SiC contact layer have the same height;

[0010] The left side of the 4H-SiC contact layer, the left side of the 4H-SiC absorption layer and the left side of the 4H-SiC epitaxial layer are etched to form a left half of the tilted mesa structure; the right side of the β-Ga2O3 contact layer, the right side of the β-Ga2O3 absorption layer and the right side of the 4H-SiC epitaxial layer are etched to form a right half of the tilted mesa structure; the upper surface of the 4H-SiC contact layer and the upper surface of the β-Ga2O3 contact layer together form an upper mesa of the tilted mesa structure; the left side wall of the 4H-SiC contact layer, the left side wall of the 4H-SiC absorption layer and part of the left side wall of the 4H-SiC epitaxial layer together form a left tilted sidewall of the tilted mesa structure; the right side wall of the β-Ga2O3 contact layer, the right side wall of the β-Ga2O3 absorption layer and part of the right side wall of the 4H-SiC epitaxial layer together form a right tilted sidewall of the tilted mesa structure; the upper surfaces on both sides of the 4H-SiC epitaxial layer form a lower mesa of the tilted mesa structure;

[0011] The passivation layer covers the entire upper surface of the device;

[0012] The N-type ohmic contact metal is arranged on both sides of the upper mesa of the tilted mesa structure; and the P-type ohmic contact metal is arranged on both sides of the lower mesa of the tilted mesa structure.

[0013] In a second aspect, the present invention provides a method for preparing a wide-spectrum response PIN high-temperature ultraviolet detector, the preparation method comprising the following steps:

[0014] forming a 4H-SiC epitaxial layer on a 4H-SiC substrate;

[0015] forming a 4H-SiC absorption layer and a β-Ga2O3 absorption layer on the 4H-SiC epitaxial layer;

[0016] forming a 4H-SiC contact layer and a β-Ga2O3 contact layer on the 4H-SiC absorption layer and the β-Ga2O3 absorption layer, respectively;

[0017] The left side of the 4H-SiC contact layer, the left side of the 4H-SiC absorption layer and the left side of the 4H-SiC epitaxial layer are etched to form a left half of the tilted mesa structure; and the right side of the β-Ga2O3 contact layer, the right side of the β-Ga2O3 absorption layer and the right side of the 4H-SiC epitaxial layer are etched to form a right half of the tilted mesa structure; wherein, the upper surface of the 4H-SiC contact layer and the upper surface of the β-Ga2O3 contact layer together form an upper mesa of the tilted mesa structure; the left side wall of the 4H-SiC contact layer, the left side wall of the 4H-SiC absorption layer and a part of the left side wall of the 4H-SiC epitaxial layer together form a left tilted sidewall of the tilted mesa structure; the right side wall of the β-Ga2O3 contact layer, the right side wall of the β-Ga2O3 absorption layer and a part of the right side wall of the 4H-SiC epitaxial layer together form a right tilted sidewall of the tilted mesa structure; the upper surfaces on both sides of the 4H-SiC epitaxial layer form a lower mesa of the tilted mesa structure;

[0018] A passivation layer is formed on the entire sample surface;

[0019] N-type ohmic contact metal and P-type ohmic contact metal are respectively prepared on the upper and lower surfaces of the tilted mesa structure, thereby completing the device preparation.

[0020] Beneficial effects of the present invention:

[0021] 1. The present invention provides a wide-spectrum response pin high-temperature ultraviolet detector that uses 4H SiC and β-Ga2O3 to form a heterojunction structure, thereby forming a pin structure ultraviolet detector. Among them, β-Ga2O3 can compensate for the low responsivity and weak short-wavelength response of 4H-SiC-based ultraviolet detectors, thereby improving the device's light response capability and detection rate, and widening the device's response bandwidth to the UVC short-wave band. When used in combination with 4H-SiC, the advantage of 4H-SiC's strong high-temperature thermal stability can be used to compensate for the disadvantage of β-Ga2O3's low thermal conductivity, thereby improving the device's heat dissipation performance and enhancing the device's thermal reliability in high-temperature applications, making it suitable for operation in high-temperature environments.

[0022] 2. The wide-spectrum response PIN high-temperature ultraviolet detector provided by the present invention is also designed with an inclined table structure and combined with a passivation layer and an optical anti-reflection layer, which reduces device leakage and improves light transmittance.

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic structural diagram of a wide-spectrum-response PIN high-temperature ultraviolet detector provided by an embodiment of the present invention;

[0025] Figure 2This is a flow chart of a method for preparing a wide-spectrum-response PIN high-temperature ultraviolet detector provided by an embodiment of the present invention;

[0026] Figures 3a-3m Schematic diagram of the preparation process of the wide-spectrum response PIN high-temperature ultraviolet detector provided by an embodiment of the present invention;

[0027] Description of reference numerals:

[0028] 1-4H-SiC substrate, 2-4H-SiC epitaxial layer, 3-4H-SiC absorption layer, 4-β-Ga2O3 absorption layer, 5-4H-SiC contact layer, 6-β-Ga2O3 contact layer, 7-passivation layer, 8-N-type ohmic contact metal, 9-P-type ohmic contact metal, 10-anti-reflection layer, 11-metal pad. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] The first aspect of the present invention provides a high-temperature PIN ultraviolet detector with a broad spectrum response. Figure 1 , Figure 1 Schematic diagram of the structure of a wide-spectrum response PIN high-temperature ultraviolet detector provided by an embodiment of the present invention. The device includes a 4H-SiC substrate 1, a 4H-SiC epitaxial layer 2, a 4H-SiC absorption layer 3, a β-Ga2O3 absorption layer 4, a 4H-SiC contact layer 5, a β-Ga2O3 contact layer 6, a passivation layer 7, an N-type ohmic contact metal 8, and a P-type ohmic contact metal 9; wherein,

[0031] The 4H-SiC epitaxial layer 2 is provided on the 4H-SiC substrate 1;

[0032] The 4H-SiC absorption layer 3 is arranged on the upper left of the 4H-SiC epitaxial layer 2; the β-Ga2O3 absorption layer 4 has the same height as the 4H-SiC absorption layer 3 and is arranged adjacent to the 4H-SiC absorption layer 3 on the upper right of the 4H-SiC epitaxial layer 2;

[0033] The 4H-SiC contact layer 5 is disposed above the 4H-SiC absorption layer 3 and aligned with the right side of the 4H-SiC absorption layer 3; the β-Ga2O3 contact layer 6 is disposed above the β-Ga2O3 absorption layer 4 and aligned with the left side of the β-Ga2O3 absorption layer 4; and the β-Ga2O3 contact layer 6 and the 4H-SiC contact layer 5 have the same height;

[0034] The left side of the 4H-SiC contact layer 5, the left side of the 4H-SiC absorption layer 3 and the left side of the 4H-SiC epitaxial layer 2 are etched to form the left half of the tilted mesa structure; the right side of the β-Ga2O3 contact layer 6, the right side of the β-Ga2O3 absorption layer 4 and the right side of the 4H-SiC epitaxial layer 2 are etched to form the right half of the tilted mesa structure; the upper surface of the 4H-SiC contact layer 5 and the upper surface of the β-Ga2O3 contact layer 6 together form the upper mesa structure. The left side wall of the 4H-SiC contact layer 5, the left side wall of the 4H-SiC absorption layer 3 and the left side wall of a portion of the 4H-SiC epitaxial layer 2 together form the left inclined side wall of the angled mesa structure; the right side wall of the β-Ga2O3 contact layer 6, the right side wall of the β-Ga2O3 absorption layer 4 and the right side wall of a portion of the 4H-SiC epitaxial layer 2 together form the right inclined side wall of the angled mesa structure; the upper surfaces on both sides of the 4H-SiC epitaxial layer 2 form the lower mesa of the angled mesa structure;

[0035] The passivation layer 7 covers the upper surface of the entire device;

[0036] N-type ohmic contact metal 8 is arranged on both sides of the upper mesa of the tilted mesa structure; P-type ohmic contact metal 9 is arranged on both sides of the lower mesa of the tilted mesa structure.

[0037] For further information, please see Figure 1 The detector further includes an anti-reflection layer 10 , which is disposed on the passivation layer 7 between the N-type ohmic contact metals 8 .

[0038] For example, the anti-reflection layer 10 can be realized by using an anti-reflection film and a nanostructure.

[0039] For further information, please see Figure 1 The detector further includes a metal Pad 11 , which is disposed on the N-type ohmic contact metal 9 on the right and the P-type ohmic contact metal 10 on the right.

[0040] Exemplarily, the material of the metal Pad 11 may be TaSi 2 / Pt / Au.

[0041] In this embodiment, the 4H-SiC substrate 1 is n+ doped; the 4H-SiC epitaxial layer 2 is p+ doped, and the doping concentration is 2.0×10 18 -1.0×10 19 cm -3 , the doping element is Al; the 4H-SiC absorption layer 3 is n-doped, and the carrier concentration is 1.0×10 15 -1.0×10 16 cm -3, doping elements are N or P; β-Ga2O3 absorption layer 4n-doped, carrier concentration is 1.0×10 15 -1.0×10 16 cm -3 , the doping element is Ge or Si; the 4H-SiC contact layer 5 and the β-Ga2O3 contact layer 6 are both n+ doped, and the carrier concentration is 1.0×10 19 -5.0×10 19 cm -3 .

[0042] Optionally, as an implementation method, the thickness of the 4H-SiC substrate 1 can be 350 μm, the thickness of the 4H-SiC epitaxial layer 2 can be 1 μm, the thickness of the 4H-SiC absorption layer 3 and the β-Ga2O3 absorption layer 4 can be 2 μm, and the thickness of the 4H-SiC contact layer 5 and the β-Ga2O3 contact layer 6 can be 0.5 μm.

[0043] For example, the passivation layer 7 may be made of SiO2 / SiN x The composite layer, with a thickness of 12-23nm, can play a role in leakage protection.

[0044] In this embodiment, the N-type ohmic contact metal and the P-type ohmic contact metal can be implemented using existing common structures, such as Pt / Ti.

[0045] Preferably, in this embodiment, Ti / TaSi2 / Ti / Pt is used to realize N-type ohmic contact, and Ni / W / TaSi2 / Ti / Pt is used to realize P-type ohmic contact.

[0046] The present invention provides a wide-spectrum response PIN high-temperature ultraviolet detector using 4H-SiC and β-Ga2O3 to form a heterojunction structure, thereby forming a PIN structure ultraviolet detector. Among them, β-Ga2O3 can compensate for the low responsivity and weak short-wavelength response of 4H-SiC-based ultraviolet detectors, thereby improving the device's light response capability and detection rate, and widening the device's response bandwidth to the UVC short-wave band. When used in combination with 4H-SiC, the advantage of 4H-SiC's strong high-temperature thermal stability can be utilized to compensate for the disadvantage of β-Ga2O3's low thermal conductivity, thereby improving the device's heat dissipation performance and enhancing the device's thermal reliability in high-temperature applications, making it suitable for working in high-temperature environments.

[0047] In addition, the wide-spectrum response PIN high-temperature ultraviolet detector provided by the present invention is also designed with an inclined table structure and combined with a passivation layer and an optical anti-reflection layer, which reduces device leakage and improves light transmittance.

[0048] The second aspect of the present invention also provides a method for preparing a wide spectrum response pin high temperature ultraviolet detector, see Figure 2, Figure 2 1 is a flow chart of a method for preparing a wide-spectrum-response PIN high-temperature ultraviolet detector provided by an embodiment of the present invention, the method specifically comprising the following steps:

[0049] Step 1: forming a 4H-SiC epitaxial layer on a 4H-SiC substrate.

[0050] First, providing an n+ type 4H-SiC substrate with a thickness of 350 μm;

[0051] Then, a p+ type 4H-SiC epitaxial layer with a thickness of 2 μm is epitaxially grown on the n+ type 4H-SiC substrate using a conventional CVD (Chemical Vapor Deposition) process;

[0052] Step 2: forming a 4H-SiC absorption layer and a β-Ga2O3 absorption layer on the 4H-SiC epitaxial layer.

[0053] 21) epitaxially growing an n-type 4H-SiC absorption layer with a thickness of 2 μm on the 4H-SiC epitaxial layer using a CVD process;

[0054] 22) Using photolithography and etching processes, a window is opened in the 4H-SiC absorption layer to expose the 4H-SiC epitaxial layer on the right side, which serves as a window for the β-Ga2O3 absorption layer;

[0055] 23) A 2 μm thick n-type β-Ga2O3 absorption layer is grown on the right side of the 4H-SiC epitaxial layer using an MBE (Molecular beam epitaxy) process.

[0056] Step 3: forming a 4H-SiC contact layer and a β-Ga2O3 contact layer on the 4H-SiC absorption layer and the β-Ga2O3 absorption layer, respectively.

[0057] 31) Growing an n+ type 4H-SiC contact layer with a thickness of 0.5 μm on the 4H-SiC absorption layer and the β-Ga2O3 absorption layer using CVD technology;

[0058] 32) Using photolithography and etching processes to open a window in the 4H-SiC contact layer to expose the β-Ga2O3 absorption layer as a window for the β-Ga2O3 contact layer;

[0059] 33) An n+ type β-Ga2O3 contact layer with a thickness of 0.5 μm is grown on the β-Ga2O3 absorption layer using an MBE epitaxial process.

[0060] Step 4: Etch the left side of the 4H-SiC contact layer, the left side of the 4H-SiC absorption layer, and the left side of the 4H-SiC epitaxial layer to form a left-half tilted mesa structure; and etch the right side of the β-Ga2O3 contact layer, the right side of the β-Ga2O3 absorption layer, and the right side of the 4H-SiC epitaxial layer to form a right-half tilted mesa structure.

[0061] The upper surface of the 4H-SiC contact layer and the upper surface of the β-Ga2O3 contact layer together form an upper mesa of the angled mesa structure; the left side wall of the 4H-SiC contact layer, the left side wall of the 4H-SiC absorption layer and a portion of the left side wall of the 4H-SiC epitaxial layer together form a left inclined sidewall of the angled mesa structure; the right side wall of the β-Ga2O3 contact layer, the right side wall of the β-Ga2O3 absorption layer and a portion of the right side wall of the 4H-SiC epitaxial layer together form a right inclined sidewall of the angled mesa structure; the upper surfaces on both sides of the 4H-SiC epitaxial layer form a lower mesa of the angled mesa structure;

[0062] Step 5: forming a passivation layer on the entire sample surface.

[0063] Step 6: Prepare N-type ohmic contact metal and P-type ohmic contact metal on the upper and lower mesas of the tilted mesa structure, respectively, to complete device preparation.

[0064] It should be noted that before preparing the N-type ohmic contact metal and the P-type ohmic contact metal, the following steps are also included:

[0065] Step x: using PECVD (plasma enhanced chemical vapor deposition) and etching processes to grow an anti-reflection and anti-transmission film and a nanostructure on the passivation layer to form an anti-reflection layer; the anti-reflection layer is specifically located between the growth positions of the two N-type ohmic contact metals.

[0066] After the N-type ohmic contact metal and the P-type ohmic contact metal are prepared, the method further includes:

[0067] Step y: using photolithography, electron beam evaporation, and etching processes, respectively, metal pads are prepared on the N-type ohmic contact metal on the right side and the P-type ohmic contact metal on the right side.

[0068] The device preparation is now completed.

[0069] The following is a specific example, combined with Figures 3a-3m The preparation process schematic diagram shown in FIG. 1 is used to introduce in detail the preparation process of the wide-spectrum response PIN high-temperature ultraviolet detector of the present invention.

[0070] S1, provide an n+ type 4H-SiC substrate 1 with a thickness of 350 μm, as shown in FIG. Figure 3a shown.

[0071] S2, epitaxially growing a p+ type 4H-SiC epitaxial layer 2 with a thickness of 1 μm on the n+ type 4H-SiC substrate 1 using a conventional CVD process, as shown in FIG. Figure 3b As shown in Figure 2, the doping concentration of the P+ type 4H-SiC epitaxial layer 2 is 2.0×10 18 -1.0×10 19 cm -3 , the doping element is Al element.

[0072] S3, epitaxially growing an n-type 4H-SiC absorption layer 3 with a thickness of 2 μm on the p+ type 4H-SiC epitaxial layer 2 by a CVD process, as shown in FIG. Figure 3c As shown. Among them, the carrier concentration of the n-type 4H-SiC absorption layer 3 is 1.0×10 15 -1.0×10 16 cm -3 , the doping element is N or P.

[0073] S4, using photolithography and etching process to open a window in the 4H-SiC absorption layer 3, exposing the 4H-SiC epitaxial layer 2 on the right side as a window for the β-Ga2O3 absorption layer 4, as shown in FIG. Figure 3d shown.

[0074] S5, using the MBE epitaxial process to grow a 2 μm thick n-type β-Ga2O3 absorption layer 4 on the right side of the 4H-SiC epitaxial layer 2, as shown in FIG. Figure 3e As shown. Among them, the carrier concentration of the n-type β-Ga2O3 absorption layer 4 is 1.0×10 15 -1.0×10 16 cm -3 , the doping element is Ge or Si.

[0075] S6, using CVD technology to grow a 0.5 μm thick n+ type 4H-SiC contact layer 5 on the n-type 4H-SiC absorption layer and the n-type β-Ga2O3 absorption layer, as shown in FIG. Figure 3f As shown. Among them, the carrier concentration of the n+ type 4H-SiC contact layer 5 is 1.0×10 19 -5.0×10 19 cm -3 .

[0076] S7, using photolithography and etching process to open a window on the 4H-SiC contact layer 5, exposing the β-Ga2O3 absorption layer 4, as a window of the β-Ga2O3 contact layer 6, as shown in FIG. Figure 3g shown.

[0077] S8, using MBE epitaxial process to grow an n+ type β-Ga2O3 contact layer 6 with a thickness of 0.5 μm on the β-Ga2O3 absorption layer 4, as shown in FIG. Figure 3h As shown. Among them, the carrier concentration of the n+ type β-Ga2O3 contact layer 6 is 1.0×10 19 -5.0×10 19 cm -3 .

[0078] S9, using photoresist reflow technology and inductively coupled plasma etching process to etch out the tilted mesa structure of the device, such as Figure 3i shown.

[0079] S10, Growth of SiO2 / SiN by Thermal Oxidation and PECVD x The composite layer is used as the passivation layer 7, and the thickness of the passivation layer 7 is 20nm-30nm. Figure 3j shown.

[0080] S11, using the PECVD method and etching process to grow an anti-reflection and anti-reflection film and a nanostructure on the passivation layer 7 to form an anti-reflection layer 10, wherein the anti-reflection layer 10 is specifically located between the growth positions of the two N-type ohmic contact metals, such as Figure 3k shown.

[0081] S12, using photolithography, etching and magnetron sputtering processes, prepare N-type ohmic contact metal 8 and P-type ohmic contact metal 9 on the upper and lower mesas of the tilted mesa structure, and perform high-temperature thermal annealing at 1100° C. in a nitrogen environment to improve the ohmic contact, such as Figure 3l shown.

[0082] S13, using photolithography, electron beam evaporation and etching processes to prepare metal Pad 11 on the right side N-type ohmic contact metal 8 and the right side P-type ohmic contact metal 9, respectively. Figure 3m shown.

[0083] The fabrication of a high-temperature, broadband-response PIN (pin) UV detector has been completed. The resulting detector utilizes a heterojunction PIN structure made of 4H-SiC and β-Ga2O3, resolving the challenges of insufficient responsivity and low detectivity associated with conventional PIN photodetectors. Furthermore, because the two materials exhibit distinct characteristic UV response bands, they complement each other to broaden the device's response range, enabling detection of short-wavelength, wide-range UV light and extending the device's UV response band. Furthermore, 4H-SiC compensates for the poor heat dissipation capabilities of β-Ga2O3, improving the device's heat dissipation and enhancing its thermal reliability in high-temperature applications, making it suitable for operation in high-temperature environments.

[0084] It should be noted that in the process of preparing high-temperature PIN ultraviolet detectors, the CVD process, photolithography and etching process, MBE epitaxial technology, photoresist reflow technology, thermal oxidation process, annealing process, electron beam evaporation process, corrosion process, etc. involved are all existing mature process means. This embodiment only provides a brief description. The detailed implementation process can refer to the existing relevant technology implementation.

[0085] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0086] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0087] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0088] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art can understand and implement other changes to the disclosed embodiments by reviewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple situations. A single processor or other unit can implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0089] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A wide spectrum response PIN high temperature ultraviolet detector, characterized in that: The invention comprises a 4H-SiC substrate (1), a 4H-SiC epitaxial layer (2), a 4H-SiC absorption layer (3), a β-Ga2O3 absorption layer (4), a 4H-SiC contact layer (5), a β-Ga2O3 contact layer (6), a passivation layer (7), an N-type ohmic contact metal (8), and a P-type ohmic contact metal (9); wherein, The 4H-SiC epitaxial layer (2) is arranged on the 4H-SiC substrate (1); The 4H-SiC absorption layer (3) is arranged on the upper left side of the 4H-SiC epitaxial layer (2); the β-Ga2O3 absorption layer (4) has the same height as the 4H-SiC absorption layer (3) and is arranged adjacent to the 4H-SiC absorption layer (3) on the upper right side of the 4H-SiC epitaxial layer (2); The 4H-SiC contact layer (5) is arranged above the 4H-SiC absorption layer (3) and aligned with the right side of the 4H-SiC absorption layer (3); the β-Ga2O3 contact layer (6) is arranged above the β-Ga2O3 absorption layer (4) and aligned with the left side of the β-Ga2O3 absorption layer (4); and the β-Ga2O3 contact layer (6) and the 4H-SiC contact layer (5) have the same height; The left side of the 4H-SiC contact layer (5), the left side of the 4H-SiC absorption layer (3) and the left side of the 4H-SiC epitaxial layer (2) are etched to form a left half tilted mesa structure; the right side of the β-Ga2O3 contact layer (6), the right side of the β-Ga2O3 absorption layer (4) and the right side of the 4H-SiC epitaxial layer (2) are etched to form a right half tilted mesa structure; the upper surface of the 4H-SiC contact layer (5) and the upper surface of the β-Ga2O3 contact layer (6) together form a tilted mesa structure. The upper mesa; the left side wall of the 4H-SiC contact layer (5), the left side wall of the 4H-SiC absorption layer (3) and a portion of the left side wall of the 4H-SiC epitaxial layer (2) together form a left inclined side wall of the angled mesa structure; the right side wall of the β-Ga2O3 contact layer (6), the right side wall of the β-Ga2O3 absorption layer (4) and a portion of the right side wall of the 4H-SiC epitaxial layer (2) together form a right inclined side wall of the angled mesa structure; the upper surfaces on both sides of the 4H-SiC epitaxial layer (2) form a lower mesa of the angled mesa structure; The passivation layer (7) covers the upper surface of the entire device; The N-type ohmic contact metal (8) is arranged on both sides of the upper mesa of the tilted mesa structure; and the P-type ohmic contact metal (9) is arranged on both sides of the lower mesa of the tilted mesa structure.

2. A wide spectrum response PIN high temperature ultraviolet detector according to claim 1, characterized in that: The detector further comprises an anti-reflection layer (10), wherein the anti-reflection layer (10) is arranged on the passivation layer (7) between the N-type ohmic contact metals (8).

3. The wide spectrum response PIN high temperature ultraviolet detector according to claim 1, characterized in that: The detector further comprises a metal pad (11), and the metal pad (11) is arranged on the N-type ohmic contact metal (9) on the right side and the P-type ohmic contact metal (10) on the right side.

4. The wide spectrum response PIN high temperature ultraviolet detector according to claim 1, characterized in that: The 4H-SiC substrate (1) is n+ doped; The 4H-SiC epitaxial layer (2) is p+ doped, and the doping concentration is 2.0×10 18 -1.0×10 19 cm -3 , the doping element is Al; The 4H-SiC absorption layer (3) is n-doped, and the carrier concentration is 1.0×10 15 -1.0×10 16 cm -3 , the doping element is N or P; The β-Ga2O3 absorption layer (4) is n-doped, and the carrier concentration is 1.0×10 15 -1.0×10 16 cm -3 , the doping element is Ge or Si; The 4H-SiC contact layer (5) and the β-Ga2O3 contact layer (6) are both n+ doped, and the carrier concentration is 1.0×10 19 -5.0×10 19 cm -3 .

5. The wide spectrum response PIN high temperature ultraviolet detector according to claim 1, characterized in that: The passivation layer (7) is made of SiO2 / SiN x The composite layer has a thickness of 12-23 nm.

6. A method for preparing a wide-spectrum response PIN high-temperature ultraviolet detector, characterized in that: The preparation method comprises the following steps: forming a 4H-SiC epitaxial layer on a 4H-SiC substrate; forming a 4H-SiC absorption layer and a β-Ga2O3 absorption layer on the 4H-SiC epitaxial layer; forming a 4H-SiC contact layer and a β-Ga2O3 contact layer on the 4H-SiC absorption layer and the β-Ga2O3 absorption layer, respectively; The left side of the 4H-SiC contact layer, the left side of the 4H-SiC absorption layer and the left side of the 4H-SiC epitaxial layer are etched to form a left half of the tilted mesa structure; and the right side of the β-Ga2O3 contact layer, the right side of the β-Ga2O3 absorption layer and the right side of the 4H-SiC epitaxial layer are etched to form a right half of the tilted mesa structure; wherein the upper surface of the 4H-SiC contact layer and the upper surface of the β-Ga2O3 contact layer together form an upper mesa of the tilted mesa structure; the left side wall of the 4H-SiC contact layer, the left side wall of the 4H-SiC absorption layer and a portion of the left side wall of the 4H-SiC epitaxial layer together form a left tilted sidewall of the tilted mesa structure; the right side wall of the β-Ga2O3 contact layer, the right side wall of the β-Ga2O3 absorption layer and a portion of the right side wall of the 4H-SiC epitaxial layer together form a right tilted sidewall of the tilted mesa structure; the upper surfaces on both sides of the 4H-SiC epitaxial layer form a lower mesa of the tilted mesa structure; A passivation layer is formed on the entire sample surface; N-type ohmic contact metal and P-type ohmic contact metal are respectively prepared on the upper mesa and the lower mesa of the tilted mesa structure, thereby completing the device preparation.

7. The method for preparing a wide-spectrum-response PIN high-temperature ultraviolet detector according to claim 6, characterized in that: Forming a 4H-SiC absorption layer and a β-Ga2O3 absorption layer on the 4H-SiC epitaxial layer specifically includes: epitaxially growing an n-type 4H-SiC absorption layer with a thickness of 2 μm on the 4H-SiC epitaxial layer using a CVD process; A window is opened in the 4H-SiC absorption layer using photolithography and etching processes to expose the 4H-SiC epitaxial layer on the right side as a window for the β-Ga2O3 absorption layer; An n-type β-Ga2O3 absorption layer with a thickness of 2 μm is grown on the right side of the 4H-SiC epitaxial layer using an MBE epitaxial process.

8. The method for preparing a wide-spectrum-response PIN high-temperature ultraviolet detector according to claim 6, characterized in that: Forming a 4H-SiC contact layer and a β-Ga2O3 contact layer on the 4H-SiC absorption layer and the β-Ga2O3 absorption layer, respectively, specifically comprising: Growing an n+ type 4H-SiC contact layer with a thickness of 0.5 μm on the 4H-SiC absorption layer and the β-Ga2O3 absorption layer using a CVD process technology; Using photolithography and etching processes to open a window in the 4H-SiC contact layer to expose the β-Ga2O3 absorption layer as a window of the β-Ga2O3 contact layer; An n+ type β-Ga2O3 contact layer with a thickness of 0.5 μm is grown on the β-Ga2O3 absorption layer using an MBE epitaxial process.

9. The method for preparing a wide-spectrum-response PIN high-temperature ultraviolet detector according to claim 6, characterized in that: Before preparing the N-type ohmic contact metal and the P-type ohmic contact metal, the method further includes: An anti-reflection and anti-reflection film and a nanostructure are grown on the passivation layer using a PECVD method and an etching process to form an anti-reflection layer; the anti-reflection layer is specifically located between the two growth positions of the N-type ohmic contact metals.

10. The method for preparing a wide-spectrum-response PIN high-temperature ultraviolet detector according to claim 6, characterized in that: After the N-type ohmic contact metal and the P-type ohmic contact metal are prepared, the method further includes: Metal pads are prepared on the N-type ohmic contact metal on the right side and the P-type ohmic contact metal on the right side respectively using photolithography, electron beam evaporation, and etching processes.

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