Short-wave indium gallium arsenic infrared detector based on flexible substrate and preparation method thereof

Abstract

The invention provides a short-wave indium gallium arsenic infrared detector based on a flexible substrate and a preparation method thereof, and belongs to the technical field of short-wave infrared detectors. The problem that a traditional InP-based indium gallium arsenic short wave infrared detector is too high in rigidity and cannot be used in buckling and special-shaped environments is solved. The method comprises the following steps: growing an N-type sacrificial layer on a substrate, wherein the N-type sacrificial layer and the substrate have high selectivity; growing an N-type buffer layer on the surface of the sacrificial layer; growing an absorption layer of a short-wave channel on the surface of the buffer layer; growing a contact layer on the surface of the absorption layer; growing a cap layer on the surface of the contact layer; manufacturing an N groove; depositing a mask; forming a P-type diffusion doping region through a diffusion process; annealing treatment is carried out after diffusion; preparing and annealing a P electrode; preparing an N electrode; removing the sacrificial layer and transferring the rest of the epitaxial structure to a flexible target substrate; the invention is applied to the infrared detector.

Description

Technical Field

[0001] This application relates to the field of short-wave infrared detector technology, and in particular to a short-wave indium gallium arsenide infrared detector based on a flexible substrate and its fabrication method. Background Technology

[0002] Low Rayleigh scattering in the short-wave infrared (SWIR) spectrum (0.9–1.7 µm) allows SWIR detectors to exhibit higher contrast in fog, haze, rain, and other low-visibility weather conditions. Therefore, images obtained from SWIR detectors are clearer than those from other infrared imaging techniques. Compared to other types of infrared detectors, SWIR detectors offer the following advantages: 1) High sensitivity: High quantum efficiency and low dark current enable the detection of weak light signals, obtaining high-quality images or measurement data even in low-light conditions. For example, they can clearly capture weak light in night vision and astronomical observation. 2) Fast response: Fast response speed allows for the detection and imaging of high-speed light signals, accurately tracking rapidly changing light signals, making them suitable for applications requiring rapid response, such as laser communication and high-speed photography. 3) High resolution: Smaller pixel size and higher pixel density enable high-resolution images or measurement results, offering advantages in fields with high resolution requirements, such as industrial inspection and medical imaging. 4) Room temperature operation: In many cases, it can operate at room temperature, eliminating the need for cryogenic cooling equipment to reduce noise and improve performance, unlike some photon detectors. This reduces system complexity and cost, and improves the portability and stability of the device. 5) Stability and reliability: Indium gallium arsenide (IGaAs) materials possess good chemical stability and mechanical properties. The detector's performance remains relatively stable over long-term use, is not easily affected by external environmental factors, and has high reliability and lifespan. It can operate stably for extended periods in harsh industrial and outdoor environments.

[0003] However, traditional InP-based indium gallium arsenide short-wave infrared detectors are too rigid, making it impossible to achieve a perfect fit in bending or irregularly shaped environments, thus affecting normal operational reliability and hindering high-precision, high-resolution imaging. Meanwhile, with the improvement of living standards and the widespread adoption of smart wearable devices, consumer demand for health monitoring and activity tracking functions is increasing, leading to a significant need for flexible sensors in products such as smart bracelets and watches. Furthermore, the advancement of Industry 4.0 is driving up demand for flexible inspection equipment in factories, and the development of intelligent vehicles is increasing the application of flexible sensors in areas such as smart seats and steering wheel pressure sensors.

[0004] Therefore, there is an urgent need in the field for a flexible short-wave infrared detector that can conform to buckling and anisotropic environments while maintaining high-precision and high-resolution imaging. Summary of the Invention

[0005] To address the aforementioned technical issues, this application proposes a short-wavelength indium gallium arsenide infrared detector based on a flexible substrate and its fabrication method.

[0006] The technical solution adopted in this application is: a method for fabricating a short-wavelength indium gallium arsenide infrared detector based on a flexible substrate, comprising the following steps: Step 1: Epitaxial structure growth: Grow an N-type sacrificial layer with high selectivity on the substrate; grow an N-type buffer layer on the surface of the sacrificial layer; grow an absorption layer for short-wavelength channels on the surface of the buffer layer; grow an N-type contact layer on the surface of the absorption layer; grow a cap layer on the surface of the contact layer. The substrate, buffer layer and contact layer are all made of InP material, while the cap layer and absorber layer are made of InGaAs material. Step 2: N-groove fabrication: This includes label photolithography, label etching, N-groove photolithography, N-groove etching, and resist removal and cleaning. In the N-groove etching, a step-by-step etching method is used, with different etching solutions used to etch InP and InGaAs materials separately. Step 3: Deposit mask; Step 4: Doping and Diffusion: The epitaxial structure after deposition mask is etched with openings to define the diffusion region. The resist is removed and the material surface of the epitaxial structure is cleaned. A P-type diffusion doped region is formed through the diffusion process. Annealing is performed after diffusion. Step 5: P-electrode preparation and annealing; Step Six: N-electrode preparation; Step 7: Substrate transfer, the specific operation steps are as follows: Step 7.1: Sacrificial layer removal: Immerse the epitaxial structure with the target material in a pre-prepared etching solution to remove the sacrificial layer, thereby separating the target material from the substrate and allowing it to float on the solution surface; wherein the target material is the buffer layer to be retained and the material above it. Step 7.2: Material Pickup: First, combine the flexible substrate with the organic substrate as the target substrate, and then use a clean target substrate to slowly contact the floating target material from below the solution, so that the target material is adsorbed on the surface of the flexible substrate of the target substrate. Step 7.3: Drying treatment; Step 7.4: Post-processing and detection.

[0007] Furthermore, in step two, the etching of InGaAs material uses a mixed solution of phosphoric acid, hydrogen peroxide, and water at an etching rate of 500-600 nm / min, while the etching of InP material uses a mixed solution of hydrochloric acid and water at an etching rate of 800-1000 nm / min.

[0008] Furthermore, in step four, the area etched by the opening is the mask and the cap layer, and the diffusion area is inside the cap layer. The diffusion process adopts closed-tube diffusion to form a P-type diffusion doped region.

[0009] Furthermore, the P electrode in step five is prepared using a nickel-platinum-gold metal system.

[0010] Furthermore, the N electrode in step six is ​​prepared using a platinum metal system.

[0011] Furthermore, in step six, magnetron sputtering and electron beam evaporation are combined to deposit the N electrode. First, magnetron sputtering is used to lay the base layer, and the deposited metals are titanium-platinum and a portion of gold. Then, electron beam evaporation is used to complete the remaining thickness of gold deposition. Finally, the adhesive is removed and the electrode is cleaned.

[0012] Furthermore, the sacrificial layer is made of InGaAs or InAlAs material.

[0013] Furthermore, when the sacrificial layer is made of InGaAs material, the sacrificial layer of InGaAs material is removed in step 7.1 using a phosphoric acid solution.

[0014] Furthermore, when the sacrificial layer is made of InAlAs material, the sacrificial layer of InAlAs material is removed in step 7.1 using a succinic acid system solution.

[0015] A short-wavelength indium gallium arsenide infrared detector based on a flexible substrate is disclosed, which is fabricated using the aforementioned method for fabricating a short-wavelength indium gallium arsenide infrared detector based on a flexible substrate.

[0016] The advantages of this application over the prior art are as follows: 1. It is easier to grow InGaAs or InAlAs sacrificial layer structures on InP substrates as sacrificial layers; 2. By adopting a combination of highly selective wet etching, the process difficulty of completely removing the substrate by traditional mechanical and chemical polishing is solved; in addition, since mechanical and chemical polishing is not used in the selective etching process, the substrate can be reused. 3. In the N-groove etching process, the highly selective wet etching solution can prevent over-etching, suppress lateral corrosion of the material, and reduce the isotropic phenomenon of wet etching. 4. PI is used as the organic substrate because of its good mechanical properties and high temperature resistance. 5. Using PDMS as the contact material after epitaxial structure transfer can achieve high adhesion, high bonding strength, and prevent the epitaxial structure from falling off. 6. By combining inorganic SWIR epitaxial materials with organic substrates, the respective material properties are fully utilized, enabling the application expansion of indium gallium arsenide shortwave infrared detectors. Attached Figure Description

[0017] The following description, in conjunction with the accompanying drawings, further illustrates this application: Figure 1 A flowchart of the preparation method provided in the embodiments of this application; Figure 2 This is a schematic diagram of the extensional structure provided in an embodiment of this application; Figure 3 This is a schematic diagram of the epitaxial structure after one-time etching of the N-groove, provided in an embodiment of this application. Figure 4 This is a schematic diagram of the epitaxial structure after N-groove step-by-step etching provided in an embodiment of this application; Figure 5 This is a schematic diagram of the epitaxial structure after deposition masking provided in an embodiment of this application; Figure 6 This is a schematic diagram of the post-diffusion epitaxial structure provided in an embodiment of this application; Figure 7 This is a schematic diagram of the epitaxial structure after P-electrode growth and annealing provided in an embodiment of this application; Figure 8 This is a schematic diagram of the epitaxial structure after N-electrode growth by magnetron sputtering and electron beam deposition, provided in an embodiment of this application. Figure 9 This is a schematic diagram of a structure in which a disconnection occurs after an N-electrode is grown using an electron beam deposition method, as provided in an embodiment of this application. Figure 10 This is a schematic diagram of the epitaxial structure after the sacrificial layer has been removed, provided in an embodiment of this application. Figure 11 This is a schematic diagram of an epitaxial structure based on a flexible substrate provided in an embodiment of this application; Figure 12 The following are test comparison diagrams of P electrode ohmic contact after annealing at 400℃ using different metal systems, provided for embodiments of this application. In the figure, (12a) is the test result diagram of P electrode ohmic contact after annealing using the titanium-platinum metal system, (12b) is the test result diagram of P electrode ohmic contact after annealing using the titanium-platinum metal system, and (12c) is the test result diagram of P electrode ohmic contact after annealing using the nickel-platinum metal system. The curves of different colors in the figure represent samples from different batches. Figure 13 The figure shows the results of a comprehensive test of the photoelectric performance of a flexible infrared detector under normal temperature conditions provided in the embodiments of this application. In the figure, (13a) is the test graph of the average dark current density per unit area, and (13b) is the test graph of the resistance RA-bias curve per unit area. In the figure: 1 is the cap layer, 2 is the contact layer, 3 is the absorption layer, 4 is the buffer layer, 5 is the sacrificial layer, 6 is the substrate, 7 is the mask, 8 is the P-type diffusion doped region, 9 is the P electrode, 10 is the N electrode, 11 is the flexible substrate, and 12 is the organic substrate. Detailed Implementation

[0018] like Figures 1 to 13 As shown, this application provides a method for fabricating a short-wavelength indium gallium arsenide infrared detector based on a flexible substrate, including the following steps: Step 1: Epitaxial Structure Growth: Growth of an epitaxial structure with a highly selective sacrificial layer 5, such as... Figure 2 As shown, a sacrificial layer 5 with high selectivity is grown on a substrate 6 with a thickness of 500-600 µm. The thickness of the sacrificial layer 5 is 500-1000 nm. A buffer layer 4 with a thickness of 500-1000 nm is grown on the surface of the sacrificial layer 5. The overall doping concentration is ≥2.0E+10. 18 cm -3 A short-wavelength absorption layer 3 with a thickness of 2000~3000 nm is grown on the surface of buffer layer 4, with an unintentional doping concentration ≤5.0E+10. 15 cm -3 A contact layer 2 with a thickness of 500~1000 nm is grown on the surface of the absorption layer 3, with an overall doping concentration ≥2.0E+10. 16 cm -3 A cap layer 1 with a thickness of 50~100nm is grown on the surface of the contact layer 2, which is unintentionally doped.

[0019] The substrate 6, buffer layer 4, and contact layer 2 are all made of InP material, while the sacrificial layer 5 is made of InGaAs or InAlAs material. The cap layer 1 and absorber layer 3 are made of InGaAs material. Furthermore, the sacrificial layer 5, buffer layer 4, and contact layer 2 are all N-type.

[0020] Step 2: N-groove fabrication: This includes mark photolithography, mark etching, N-groove photolithography and N-groove etching, and resist removal and cleaning. In the N-groove etching step, this application employs a step-by-step etching method.

[0021] If the N-groove etching in this application adopts the method of etching to the buffer layer 4 in one go, it requires two different materials (i.e., InP and InGaAs). If a solution with a volume ratio of hydrochloric acid:phosphoric acid:hydrogen peroxide:water = 1:1:1:1 is used and etched for 10 minutes in one go, it will cause uneven sidewall etching, blackening in some places, and difficulty in removing the resist after N-groove etching. Resin threads and resist masks will exist at the edge of the N-groove. At the same time, it will also cause severe lateral corrosion of the InP material layer, with a corrosion width of at least 20µm, causing instability in subsequent processes. Figure 2This is a schematic diagram of an epitaxial structure etched in a single pass. Due to the different materials and the gradual decrease in etching rate layer by layer, [the following occurs]. Figure 2 The structure shown indicates that a change in the process route is required.

[0022] To address the different properties of InP and InGaAs materials, this application employs separate etching methods for each material during N-groove etching. For InGaAs etching, a mixture of phosphoric acid, hydrogen peroxide, and water in a volume ratio of 2:3:30 is used, with an etching rate of 500–600 nm / min. For InP etching, a mixture of hydrochloric acid and water in a volume ratio of 2:1 is used, with an etching rate of 800–1000 nm / min. This step-by-step etching approach achieves high selectivity for both materials while suppressing lateral corrosion, preventing mask 7 (passivation layer) detachment and subsequent device failure. Figure 3 The diagram shown is a schematic of the epitaxial structure after step-by-step etching.

[0023] Step 3: Deposition of Mask 7: To meet the requirements of the subsequent annealing process, a low-stress diffusion mask 7 needs to be prepared. Silicon nitride or silicon oxide is typically chosen, and the growth method is ICPCVD (Inductively Coupled Plasma Chemical Vapor Deposition), with a temperature of 130℃, a deposition thickness of 200~300nm, an etching rate of 0.5±0.1nm / s, and a stress of 100±30MPA. The epitaxial structure after deposition of mask 7 is shown below. Figure 5 As shown.

[0024] Step 4: Doping and Diffusion: The epitaxial structure after mask 7 is etched with openings to define the diffusion region. The resist is then removed and the material surface of the epitaxial structure is cleaned. Within the cap layer 1, a P-type diffusion doped region 8 with a depth of 500~1000nm is formed through a diffusion process, with an overall doping concentration ≥2.0E+10⁻⁶. 18 cm -3 The diffusion process employs closed-tube diffusion, where a gaseous impurity source contacts the cap layer 1, maintaining a temperature of 480-500℃ for 2-4 hours. This allows impurity atoms to diffuse into the cap layer 1, forming a P-type diffusion-doped region 8. After diffusion, annealing is performed to repair lattice damage during the high-temperature diffusion process and further activate the impurity atoms. The epitaxial structure after diffusion is shown below. Figure 6 As shown, this application forms a planar junction (i.e., a lateral PN junction) through a diffusion process.

[0025] Step 5: P-electrode 9 Fabrication and Annealing: Good ohmic contact is crucial for the performance, reliability, and stability of the device. For InGaAs infrared detectors, ohmic contact is a significant factor affecting their photoelectric performance. Due to the high potential barrier height between most metals and P-InP, and the large effective hole mass of P-InP, achieving ohmic contact in P-InP is difficult. Currently, commonly used contact metals for P-InP are AuZn-based and Ni-based film systems. Through multiple rounds of experiments, comparing various metal systems such as titanium-platinum, titanium, palladium, palladium-platinum, and nickel-platinum, this application ultimately selected a nickel-platinum metal system with a thickness of 50:50:300 nm to fabricate the P-electrode 9. Annealing temperatures of 390–420℃ and annealing times of 30–180 s were selected, ultimately yielding a P-electrode 9 with a contact resistance of 100 Ω–200 Ω. Figure 7 As shown.

[0026] Figure 12 This is a comparative test of the 9-ohm contact of the P electrode after annealing with different metal systems at an annealing temperature of 400℃.

[0027] Step Six: Fabrication of N-Electrode 10: N-electrode 10 is fabricated using a titanium-platinum alloy with a thickness of 50:50:500 nm. To better meet the metal "climbing" effect while also considering the lift-off process, this application employs a combination of magnetron sputtering and electron beam evaporation for N-electrode 10 deposition. First, magnetron sputtering is used for the base layer, with a titanium-platinum alloy thickness of 50:50:200 nm. Then, electron beam evaporation is used to complete the 300 nm gold deposition. Finally, an acetone spray gun is used for lift-off and cleaning to remove the adhesive. If only electron beam evaporation is used, the electrode cannot extend from the bottom of the N-groove to the surface of the cap layer 1, which can easily lead to signal interruption and device failure. Figure 8 and 9 As shown, Figure 8 This is a schematic diagram of the epitaxial structure after N-electrode 10 is grown by magnetron sputtering and electron beam deposition. Figure 9 This is a schematic diagram of the structure in which the N-electrode 10 is disconnected after being grown by electron beam deposition.

[0028] Step 7: Substrate 6 Transfer: Based on the material properties of substrate 6 and sacrificial layer 5, select a suitable etchant or solvent, and achieve damage-free peeling of substrate 6 through a large etching selectivity ratio (50:1~100:1). Specific operation steps are as follows: Step 7.1: Removal of Sacrificial Layer 5: The epitaxial structure containing the target material (i.e., the buffer layer 4 to be retained and the material above it) is immersed in a pre-prepared solution. Chemical etching is used to dissolve the sacrificial layer 5 material between the substrate 6 and the target material, causing the target material to separate from the substrate 6 and float on the solution surface. The key to this step is controlling the etching time and solution concentration to avoid excessive etching that could damage the target material. Figure 10 This is a schematic diagram of the epitaxial structure after removing sacrificial layer 5.

[0029] Step 7.2: Material Pickup: First, combine the flexible substrate 11 with the organic substrate 12 as the target substrate. Then, use a clean target substrate to slowly contact the floating target material from below the solution, so that the target material is adsorbed onto the surface of the flexible substrate 11 of the target substrate. The operation should be gentle to avoid material wrinkling or damage.

[0030] Step 7.3: Drying treatment: Dry the target substrate with the target material attached (e.g., natural air drying, nitrogen blowing, low temperature baking, etc.) to remove residual solution. The drying process should be uniform to avoid material deformation or contamination due to solvent residue.

[0031] Step 7.4: Post-processing and inspection: Clean the surface of the target material with solutions such as acetone, ethanol, and isopropanol to remove residual impurities or solution ions. Observe the target material using optical microscopes, scanning electron microscopes (SEM), etc., to confirm whether the target material is intact, wrinkled, or damaged, and to confirm the transfer effect. Figure 11 The diagram shows the epitaxial structure based on a flexible substrate after the transfer of substrate 6.

[0032] The flexible substrate 11 can be made of polydimethylsiloxane (PDMS) material, and the organic substrate 12 can be made of polyimide (PI), polyethylene terephthalate (PET) or parylene (Paraline). Different materials are suitable for different scenarios, and the best suitable material can be selected according to the specific application environment, taking into account the placement of the infrared detector, operating temperature, humidity and other conditions.

[0033] The flexible substrate 11 of this application uses PDMS as the contact material with the epitaxial structure after transfer, which can achieve high adhesion and high bonding, making the epitaxial structure less likely to fall off.

[0034] The present application will be further described below with reference to different embodiments.

[0035] Example 1: The sacrificial layer 5 is made of InGaAs material, specifically In 0.53 Ga 0.47 As, with a thickness of 1000 nm, the fabrication steps of a short-wavelength indium gallium arsenide infrared detector based on a flexible substrate are as follows: Step 1: Epitaxial structure growth: An InGaAs sacrificial layer 5 with a thickness of 1000 nm is grown on the substrate 6. Then, a buffer layer 4, an absorption layer 3, a contact layer 2, and a cap layer 1 are grown sequentially from bottom to top on the sacrificial layer 5.

[0036] Step 2: N-groove fabrication: This includes plate marking photolithography, plate marking etching, N-groove photolithography and N-groove etching, and resist removal and cleaning.

[0037] Step 3: Deposit mask 7.

[0038] Step 4: Doping and diffusion: The epitaxial structure after deposition mask 7 is etched with openings to define the diffusion region. The resist is removed and the material surface of the epitaxial structure is cleaned to form a P-type diffusion doped region 8. Annealing is performed after diffusion.

[0039] Step 5: Preparation and annealing of P electrode 9.

[0040] Step 6: Preparation of N electrode 10.

[0041] Step 7: Substrate 6 transfer, the specific operation steps are as follows: Step 7.1: Removal of sacrificial layer 5: Immerse the epitaxial structure with the target material into a pre-prepared phosphoric acid solution. Use the phosphoric acid solution to remove the sacrificial layer 5 of the InGaAs material. At the same time, the phosphoric acid solution does not chemically react with the target material, so that the target material separates from the substrate 6 and floats on the surface of the solution.

[0042] Step 7.2: Material Pickup: First, combine the flexible substrate 11 with the organic substrate 12 as the target substrate. Then, use a clean target substrate to slowly contact the floating target material from below the solution, so that the target material is adsorbed onto the surface of the flexible substrate 11 of the target substrate. The operation should be gentle to avoid material wrinkling or damage.

[0043] Step 7.3: Drying treatment: Dry the target substrate with the target material to remove residual solution. The drying process should be uniform to avoid material deformation or contamination due to solvent residue.

[0044] Step 7.4: Post-processing and inspection: Clean the surface of the target material with solutions such as acetone, ethanol, and isopropanol to remove residual impurities or solution ions. Observe the target material for integrity, wrinkles, or damage using optical microscopes, scanning electron microscopes (SEM), etc., to confirm the transfer effect.

[0045] Example 2: The sacrificial layer 5 is made of InAlAs material. The steps of the fabrication method for the short-wavelength indium gallium arsenide infrared detector based on a flexible substrate are as follows: Step 1: Epitaxial structure growth: An InAlAs sacrificial layer 5 with a thickness of 800 nm is grown on the substrate 6. Then, a buffer layer 4, an absorption layer 3, a contact layer 2 and a cap layer 1 are grown sequentially from bottom to top on the sacrificial layer 5.

[0046] Step 2: N-groove fabrication: This includes plate marking photolithography, plate marking etching, N-groove photolithography and N-groove etching, and resist removal and cleaning.

[0047] Step 3: Deposit mask 7.

[0048] Step 4: Doping and diffusion: The epitaxial structure after deposition mask 7 is etched with openings to define the diffusion region. The resist is removed and the material surface of the epitaxial structure is cleaned to form a P-type diffusion doped region 8. Annealing is performed after diffusion.

[0049] Step 5: Preparation and annealing of P electrode 9.

[0050] Step 6: Preparation of N electrode 10.

[0051] Step 7: Substrate 6 transfer, the specific operation steps are as follows: Step 7.1: Sacrificial layer 5 removal: Immerse the epitaxial structure with the target material into a pre-prepared succinic acid solution. Use the succinic acid solution to remove the sacrificial layer 5 of the InAlAs material. At the same time, the succinic acid solution does not chemically react with the target material, allowing the target material to separate from the substrate 6 and float on the solution surface.

[0052] Step 7.2: Material Pickup: First, combine the flexible substrate 11 with the organic substrate 12 as the target substrate. Then, use a clean target substrate to slowly contact the floating target material from below the solution, so that the target material is adsorbed onto the surface of the flexible substrate 11 of the target substrate. The operation should be gentle to avoid material wrinkling or damage.

[0053] Step 7.3: Drying treatment: Dry the target substrate with the target material to remove residual solution. The drying process should be uniform to avoid material deformation or contamination due to solvent residue.

[0054] Step 7.4: Post-processing and inspection: Clean the surface of the target material with solutions such as acetone, ethanol, and isopropanol to remove residual impurities or solution ions. Observe the target material for integrity, wrinkles, or damage using optical microscopes, scanning electron microscopes (SEM), etc., to confirm the transfer effect.

[0055] This application also proposes a short-wavelength indium gallium arsenide infrared detector based on a flexible substrate, prepared using the above-described method.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for fabricating a short-wavelength indium gallium arsenide infrared detector based on a flexible substrate, characterized in that: Includes the following steps: Step 1: Epitaxial structure growth: Grow an N-type sacrificial layer with high selectivity on the substrate; grow an N-type buffer layer on the surface of the sacrificial layer; grow an absorption layer for short-wavelength channels on the surface of the buffer layer; grow an N-type contact layer on the surface of the absorption layer; grow a cap layer on the surface of the contact layer. The substrate, buffer layer and contact layer are all made of InP material, while the cap layer and absorber layer are made of InGaAs material. Step 2: N-groove fabrication: This includes label photolithography, label etching, N-groove photolithography, N-groove etching, and resist removal and cleaning. In the N-groove etching, a step-by-step etching method is used, with different etching solutions used to etch InP and InGaAs materials separately. Step 3: Deposit mask; Step 4: Doping and Diffusion: The epitaxial structure after deposition mask is etched with openings to define the diffusion region. The resist is removed and the material surface of the epitaxial structure is cleaned. A P-type diffusion doped region is formed through the diffusion process. Annealing is performed after diffusion; Step 5: P-electrode preparation and annealing; Step Six: N-electrode preparation; Step 7: Substrate transfer, the specific operation steps are as follows: Step 7.1: Sacrificial layer removal: Immerse the epitaxial structure with the target material into a pre-prepared etching solution to remove the sacrificial layer, thereby separating the target material from the substrate and allowing it to float on the solution surface; The target material is the buffer layer and the material on top of it that need to be retained; Step 7.2: Material Pickup: First, combine the flexible substrate with the organic substrate as the target substrate, and then use a clean target substrate to slowly contact the floating target material from below the solution, so that the target material is adsorbed on the surface of the flexible substrate of the target substrate. Step 7.3: Drying treatment; Step 7.4: Post-processing and detection.

2. The method for fabricating a short-wavelength indium gallium arsenide infrared detector based on a flexible substrate according to claim 1, characterized in that: In step two, the etching of InGaAs material uses a mixed solution of phosphoric acid, hydrogen peroxide and water at an etching rate of 500~600 nm / min, while the etching of InP material uses a mixed solution of hydrochloric acid and water at an etching rate of 800~1000 nm / min.

3. The method for fabricating a short-wavelength indium gallium arsenide infrared detector based on a flexible substrate according to claim 2, characterized in that: In step four, the area etched with openings is the mask and the cap layer. The diffusion region is inside the cap layer. The diffusion process uses closed-tube diffusion to form a P-type diffusion doped region.

4. The method for fabricating a short-wavelength indium gallium arsenide infrared detector based on a flexible substrate according to claim 1, characterized in that: The P electrode in step five is prepared using a nickel-platinum-gold metal system.

5. The method for fabricating a short-wavelength indium gallium arsenide infrared detector based on a flexible substrate according to claim 1, characterized in that: The N electrode in step six is ​​prepared using the platinum metal system.

6. The method for fabricating a short-wavelength indium gallium arsenide infrared detector based on a flexible substrate according to claim 5, characterized in that: In step six, magnetron sputtering and electron beam evaporation are combined to deposit the N electrode. First, magnetron sputtering is used to lay the base layer, and the deposited metals are titanium-platinum and a portion of gold. Then, electron beam evaporation is used to complete the remaining thickness of gold deposition. Finally, the adhesive is removed and the electrode is cleaned.

7. The method for fabricating a short-wavelength indium gallium arsenide infrared detector based on a flexible substrate according to claim 1, characterized in that: The sacrificial layer is made of InGaAs or InAlAs material.

8. The method for fabricating a short-wavelength indium gallium arsenide infrared detector based on a flexible substrate according to claim 7, characterized in that: When the sacrificial layer is made of InGaAs material, the sacrificial layer of InGaAs material is removed in step 7.1 using a phosphoric acid solution.

9. The method for fabricating a short-wavelength indium gallium arsenide infrared detector based on a flexible substrate according to claim 7, characterized in that: When the sacrificial layer is made of InAlAs material, the sacrificial layer of InAlAs material is removed in step 7.1 using a succinic acid system solution.

10. A short-wavelength indium gallium arsenide infrared detector based on a flexible substrate, characterized in that: The infrared detector was fabricated using the method for fabricating a short-wavelength indium gallium arsenide infrared detector based on a flexible substrate as described in any one of claims 1-9.

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