Wide-spectrum response pin high-temperature ultraviolet detector and preparation method thereof

Abstract

The invention discloses a wide-spectrum response pin high-temperature ultraviolet detector, which belongs to the technical field of microelectronics and comprises a 4H-SiC substrate, a 4H-SiC epitaxial layer arranged on the 4H-SiC substrate, a 4H-SiC absorption layer and a beta-Ga2O3 absorption layer which are arranged on the left side and the right side of the upper surface of the 4H-SiC epitaxial layer, a 4H-SiC contact layer arranged on the 4H-SiC absorption layer and a beta-Ga2O3 contact layer arranged on the beta-Ga2O3 absorption layer. 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 respectively provided with a left half dip angle mesa structure. The right sides of the beta-Ga2O3 contact layer, the beta-Ga2O3 absorption layer and the 4H-SiC epitaxial layer are provided with right half part inclined table-board structures; the N / P-type ohmic contact metal is arranged on the upper / lower mesa of the inclined mesa structure. The detector is high in light response capability and wide in detection wavelength range.

Description

Technical Field

[0001] The invention belongs to the field of microelectronic technology, 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 can convert ultraviolet light signals into electrical signals. They are widely used in weather monitoring, fire alarms, space detection, cell detection, and ultraviolet radiation measurement, and have extremely high civil and defense value. Compared with silicon-based devices widely used in long-wave photodetectors, wide-bandgap semiconductors have incomparable advantages in the field of ultraviolet detection. The most obvious advantage is their inherent visible light blindness and solar blindness, which avoids the cost waste caused by additional filtering equipment. In addition, the gradual optimization and update of wide-bandgap semiconductor material growth equipment and conditions and the continuous breakthroughs in growth technology have promoted the development and progress of wide-bandgap ultraviolet detection.

[0003] Due to its excellent material properties, SiC-based semiconductor devices play an important role in high-temperature applications. At present, common high-temperature ultraviolet detectors are mainly photodiodes, including SBD (Schottky Barrier Diode), pn junction, pin and APD (Avalanche Photon Diode). Among them, the SBD type detector has a large leakage current, the pn junction type has a low utilization rate of light, and the APD type has too high noise. The pin type helps to reduce the power consumption and high-temperature dark current of the device, and is 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] In order to solve the problems of low gain, low responsivity and narrow detection wavelength range in the prior art 4H-SiC single-material ultraviolet photodetector, the present invention provides a wide-spectrum response pin high-temperature ultraviolet detector and a preparation method thereof. The technical problem to be solved by the present invention is achieved by the following technical solutions:

[0006] In the 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 disposed on the 4H-SiC substrate;

[0008] The 4H-SiC absorption layer is arranged at 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 at 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 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;

[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 inclined mesa structure; and the P-type ohmic contact metal is arranged on both sides of the lower mesa of the inclined 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] Formation of a passivation layer over the entire sample surface;

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

[0020] Beneficial effects of the present invention:

[0021] 1. The wide-spectrum response pin high-temperature ultraviolet detector provided by the present invention uses 4H SiC and β-Ga2O3 to form a heterojunction structure, thereby forming a pin structure ultraviolet detector, wherein β-Ga2O3 can make up for the low responsivity and weak short-wavelength response of the 4H-SiC-based ultraviolet detector, thereby improving the light response ability and detection rate of the device, and widening the response bandwidth of the device 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 make up for the disadvantage of β-Ga2O3's low thermal conductivity, thereby improving the heat dissipation performance of the device, improving the thermal reliability of the device in high-temperature applications, and being suitable for working 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 It is a structural schematic diagram of a wide-spectrum response PIN high-temperature ultraviolet detector provided by an embodiment of the present invention;

[0025] Figure 2It is a schematic 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] Figure 3a-3m It is a 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 be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work 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 wide spectrum response. Figure 1 , Figure 1 1 is a 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 disposed 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 next 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 has the same height as the 4H-SiC contact layer 5;

[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 a 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 a 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 of the tilted 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 part 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 part 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] The N-type ohmic contact metal 8 is arranged on both sides of the upper mesa of the angled mesa structure; the P-type ohmic contact metal 9 is arranged on both sides of the lower mesa of the angled 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] Exemplarily, 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 350μm, the thickness of the 4H-SiC epitaxial layer 2 can be 1μm, the thickness of the 4H-SiC absorption layer 3 and the β-Ga2O3 absorption layer 4 can be 2μm, and the thickness of the 4H-SiC contact layer 5 and the β-Ga2O3 contact layer 6 can be 0.5μm.

[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, this embodiment uses Ti / TaSi2 / Ti / Pt to realize N-type ohmic contact, and uses Ni / W / TaSi2 / Ti / Pt to realize P-type ohmic contact.

[0046] A wide-spectrum response pin high-temperature ultraviolet detector provided by the present invention utilizes 4H-SiC and β-Ga2O3 to form a heterojunction structure, thereby forming a pin structure ultraviolet detector, wherein β-Ga2O3 can make up for the problems of low responsivity and weak short-wavelength response of 4H-SiC-based ultraviolet detectors, thereby improving the light response capability and detection rate of the device, and widening the response bandwidth of the device 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 make up for the disadvantage of low thermal conductivity of β-Ga2O3, thereby improving the heat dissipation performance of the device, and improving the thermal reliability of the device in high-temperature applications, and being 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, thereby reducing device leakage and improving 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, an n+ type 4H-SiC substrate with a thickness of 350 μm is provided;

[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 Depositio) 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 to open a window in the 4H-SiC absorption layer, exposing the 4H-SiC epitaxial layer on the right side 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) epitaxial process.

[0056] Step 3: Form 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 a CVD process technology;

[0058] 32) using photolithography and etching processes to open windows in the 4H-SiC contact layer, exposing 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 table of the angled table structure; the left side wall of the 4H-SiC contact layer, the left side wall of the 4H-SiC absorption layer and the left side wall of a part of the 4H-SiC epitaxial layer together form a left inclined side wall of the angled table structure; the right side wall of the β-Ga2O3 contact layer, the right side wall of the β-Ga2O3 absorption layer and the right side wall of a part of the 4H-SiC epitaxial layer together form a right inclined side wall of the angled table structure; the upper surfaces on both sides of the 4H-SiC epitaxial layer form a lower table of the angled table 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 mesa and lower mesa of the tilted mesa structure respectively, thereby completing the 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 a PECVD (plasma enhanced chemical vapor deposition) method and an etching process 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 to prepare metal pads on the N-type ohmic contact metal on the right side and the P-type ohmic contact metal on the right side respectively.

[0068] The device preparation is now completed.

[0069] The following is a specific example, combined with Figure 3a-3m The preparation process schematic diagram shown in the figure introduces in detail the preparation process of the wide-spectrum response PIN high-temperature ultraviolet detector of the present invention.

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

[0071] S2, epitaxially grow 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 Figure 3b As shown in the figure, 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, such as Figure 3c As shown in Figure 2, 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 processes 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, such as Figure 3d shown.

[0074] S5, using the MBE epitaxial process to grow an n-type β-Ga2O3 absorption layer 4 with a thickness of 2 μm on the right side of the 4H-SiC epitaxial layer 2, such as 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 elements are Ge or Si.

[0075] S6, using CVD process technology to grow an n+ type 4H-SiC contact layer 5 with a thickness of 0.5 μm on the n-type 4H-SiC absorption layer and the n-type β-Ga2O3 absorption layer, such as 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 processes to open a window in the 4H-SiC contact layer 5, exposing the β-Ga2O3 absorption layer 4, as a window of the β-Ga2O3 contact layer 6, such as 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, such as 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 terrace structure of the device, such as Figure 3i shown.

[0079] S10, Growth of SiO2 / SiN by Thermal Oxidation and PECVD Process 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 a PECVD method and an 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, preparing N-type ohmic contact metal 8 and P-type ohmic contact metal 9 on the upper table and the lower table of the tilted table structure respectively, and performing 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 N-type ohmic contact metal 8 and the right P-type ohmic contact metal 9, respectively, as shown in FIG. Figure 3m shown.

[0083] At this point, the preparation of the wide-spectrum response pin high-temperature ultraviolet detector has been completed. The prepared detector uses 4H-SiC and β-Ga2O3 to form a heterojunction pin structure, which solves the problems of insufficient responsivity and low detection rate of traditional pin photodetectors. Since the two materials have different characteristic bands for ultraviolet light response, they can complement each other to broaden the response range of the device, realize the detection function of short-wave and wide-range ultraviolet light, and broaden the device's response band to ultraviolet light. In addition, 4H-SiC can make up for the disadvantage of the low heat dissipation capacity of β-Ga2O3, improve the heat dissipation performance of the device, and enhance the thermal reliability of the device in high-temperature applications, making it suitable for working 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 makes 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 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 referred device or element 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 clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0087] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means 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 may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the 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 may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in a claim. 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 contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope 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 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); The 4H-SiC contact layer (5) is disposed above the 4H-SiC absorption layer (3) and is 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 is 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 table; the left side wall of the 4H-SiC contact layer (5), the left side wall of the 4H-SiC absorption layer (3) and part of the left side wall of the 4H-SiC epitaxial layer (2) together form the left inclined side wall of the angled table structure; the right side wall of the β-Ga2O3 contact layer (6), the right side wall of the β-Ga2O3 absorption layer (4) and part of the right side wall of the 4H-SiC epitaxial layer (2) together form the right inclined side wall of the angled table structure; the upper surfaces on both sides of the 4H-SiC epitaxial layer (2) form the lower table of the angled table 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 inclined mesa structure; and the P-type ohmic contact metal (9) is arranged on both sides of the lower mesa of the inclined 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. A wide spectrum response PIN high temperature ultraviolet detector according to claim 1, characterized in that: The detector further comprises a metal pad (11), wherein 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. A 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 12-23nm.

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 part of the left side wall of the 4H-SiC epitaxial layer together form a left inclined 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 inclined 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; Formation of a passivation layer over 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 by using a CVD process; The 4H-SiC absorption layer is opened by using photolithography and etching processes to expose the 4H-SiC epitaxial layer on the right side as a window of 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 by using a CVD process technology; Opening a window on the 4H-SiC contact layer by using photolithography and etching processes 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 by 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: The anti-reflection and anti-transmission film and the nanostructure are grown on the passivation layer by using the PECVD method and the etching process 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.

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 on the P-type ohmic contact metal on the right side respectively by using photolithography, electron beam evaporation process and etching process.

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