A photosensitive element structure of a wide-spectrum InGaAs detector and its preparation method

Abstract

The present invention discloses a photosensitive element structure of a wide spectrum InGaAs detector and a preparation method thereof, wherein the photosensitive element structure comprises an InP corrosion cutoff layer, an InGaAs ... 0.53 Ga 0.47 As absorption layer, In x Ga 1‑x As composition graded absorption layer, dislocation barrier layer, high In composition InGaAs absorption layer, high In composition InAlAs contact layer. x Ga 1‑x The x of the As composition graded absorption layer is selected from the In x Ga 1‑x The As composition gradient absorption layer linearly changes from 0.53 to a from the lower end to the upper end, 0.53 < a ≤ 1, and the high In composition InGaAs absorption layer and the In x Ga 1‑x The upper end of the As composition graded layer is lattice matched, and the dislocation barrier layer is made of InAlAs or InAsP that is lattice matched with the high In composition InGaAs absorption layer. A method for preparing the photosensitive element structure is also disclosed, the main steps of which are: pretreatment of the InP substrate, growth of epitaxial material, mechanical grinding and wet chemical etching to remove the InP substrate, selective chemical etching to remove the In 0.53 Ga 0.47 The invention is conducive to realizing a single wide-spectrum InGaAs detector that responds in the visible-shortwave infrared range.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor thin film materials, and in particular relates to a photosensitive element structure of a wide-spectrum InGaAs detector and a preparation method thereof. Background Art

[0002] Short-wave infrared photodetectors fabricated from the III-V InP / InGaAs material system offer advantages such as room-temperature operation, high sensitivity, high detectivity, high reliability, low power consumption, and high stability. They are widely used in a variety of important fields, including space remote sensing, atmospheric monitoring, and resource exploration. In these fields, the near-infrared band contains atmospheric absorption lines from gases such as O₂, CO₂, CH₄, CO, H₂O, and N₂O. High-performance visible-to-short-wave infrared broadband detectors operating in the 0.7μm, 1.2μm, 1.6μm, 2.2μm, and 2.5μm bands are in urgent need. Minerals such as hydrocarbons, clay minerals, and phosphates also exhibit multiple characteristic peaks in the 0.4-2.6μm range. In low-light-level night vision and security monitoring, photon energy in low-light environments such as night sky and moonlight is primarily distributed in the visible-to-shortwave infrared band, with photon radiance being stronger in the visible band. To improve the sensitivity and resolution of detectors in night vision environments, it is necessary to increase photon detection capabilities in the visible band. Therefore, wide-spectrum detectors with a response band covering the visible-to-shortwave infrared band play an important role.

[0003] The standard response spectrum of conventional lattice-matched InP / InGaAs detectors can only cover the short-wave infrared band of 900-1700nm. Currently, a large number of studies and applications have demonstrated that visible-extended InGaAs detectors prepared by etching and stripping InP substrates can achieve a spectral response range of 400-1700nm. In 2005, Sensor Unlimited, a US company, prepared an InGaAs visible-extended focal plane detector by stripping the InP substrate. In 2019, the Shanghai Institute of Technical Physics, Chinese Academy of Sciences, successfully prepared a visible-extended InGaAs focal plane detector with a spectral range covering 500-1700nm using inductively coupled plasma etching technology. The purpose of wavelength extension can be achieved by increasing the In component in InGaAs, but there is currently no substrate that is lattice-matched to high-In component InGaAs. It is necessary to achieve lattice relaxation by adding a heterogeneous buffer layer to obtain a high-quality InGaAs detector material with a spectral range covering an extended wavelength of 1100-2600nm. However, extended wavelength materials are not easily used for visible light extension. This is because thin InP etch-stop layers can produce dislocations due to lattice mismatch, losing their etch-stop function. Thicker etch-stop layers absorb light in the visible range, preventing detection. To achieve a wide-spectrum InGaAs detector with a visible-to-shortwave infrared response wavelength range covering 400 to 2600 nm, technological innovations are required in both the visible and extended wavelength material structure designs of the InGaAs detector, enabling both low-damage removal of the InP substrate and efficient response to the extended wavelength spectral range. Summary of the Invention

[0004] The main purpose of the present invention is to provide a photosensitive element structure of a wide-spectrum InGaAs detector and a preparation method thereof, aiming to solve the problem that the existing single InGaAs detector has a narrow spectral range.

[0005] In order to solve the above problems, the present invention discloses a photosensitive element structure of a wide spectrum InGaAs detector, which comprises, from bottom to top, an InP corrosion cutoff layer 1, an In 0.53 Ga 0.47 As absorption layer 2, In x Ga 1-x As composition graded absorption layer 3, dislocation barrier layer 4, high In composition InGaAs absorption layer 5, high In composition InAlAs contact layer 6, see attached Figure 1 .

[0006] Furthermore, the thickness of the InP corrosion stop layer is 10-100 nm, the doping type is N-type doping, and the doping concentration is 5×10 17 -5×10 18 cm -3 .

[0007] Furthermore, the In 0.53 Ga 0.47 The thickness of the As absorption layer is 500-800 nm, the doping type is N-type, and the doping concentration is 1×10 15 -5×10 16 cm -3 ; The In x Ga 1-x The thickness of the As component graded absorption layer is 800-1400 nm, and x is selected from the In x Ga 1-x The As composition of the graded absorption layer increases linearly from 0.53 to a along the thickness direction from the bottom to the top, 0.53<a≤1, the doping type is N-type, and the doping concentration is 1×10 15 -5×10 16 cm -3 The high In component InGaAs absorption layer and the In x Ga 1- x The As composition graded absorption layer has a lattice matching top, a thickness of 500-800 nm, an N-type doping type, and a doping concentration of 1×10 15 -5×10 16 cm -3 .

[0008] Furthermore, the dislocation barrier layer is x Ga 1-x The upper end of the As composition graded absorption layer is lattice-matched InAlAs or InAsP with a thickness of 50-150 nm, a weak N-type doping type, and a doping concentration of 1×10 15 -5×10 16 cm -3 .

[0009] Furthermore, the thickness of the high In content InAlAs contact layer (6) is 500-1000 nm. The doping type is P type, and the doping concentration is 3×10 18 -5×10 18 cm -3 ; or the doping type is weak N-type, and the doping concentration is 1×10 15 -5×10 16 cm -3 .

[0010] The present invention also discloses a method for preparing a wide-spectrum InGaAs detector photosensitive element structure, which is used to prepare the above-mentioned wide-spectrum InGaAs detector photosensitive element structure, comprising the following steps:

[0011] The InP substrate is placed in a molecular beam epitaxy reaction chamber, and the InP substrate is pre-heated to remove the surface oxide of the InP substrate at 600-650° C. for 3-6 minutes;

[0012] Epitaxial wafers are grown using epitaxial technology, and In is grown on InP substrates. 0.53 Ga 0.47 As etched the sacrificial layer, and the sample holder temperature was 550–600 °C;

[0013] In 0.53 Ga 0.47 The As-etched sacrificial layer is epitaxially grown to form the InP-etched stop layer, and the sample holder temperature is 500–550°C;

[0014] Epitaxially grow the InP etching stop layer. 0.53 Ga 0.47 As absorption layer, sample holder temperature was 550–600 °C;

[0015] In the 0.53 Ga 0.47 The In is epitaxially grown on the As absorption layer. x Ga 1-x As composition graded absorption layer, sample holder temperature 550–600°C;

[0016] In the x Ga 1-x Epitaxially growing the dislocation barrier layer on the As composition graded absorption layer, the sample holder temperature is 530–580°C;

[0017] Epitaxially growing the high-In content InGaAs absorption layer on the dislocation barrier layer at a sample holder temperature of 530–580° C.

[0018] Epitaxially growing the high-In content InAlAs contact layer on the high-In content InGaAs absorption layer, with the sample holder temperature being 530–580° C.;

[0019] The InP substrate was thinned to less than 10 μm by mechanical grinding, and the remaining InP substrate was removed by etching with a mixed solution of hydrochloric acid and phosphoric acid. 0.53 Ga 0.47 As corrosion sacrificial layer selectively cuts off;

[0020] In was removed by etching with a mixture of phosphoric acid and hydrogen peroxide. 0.53 Ga 0.47 As etches the sacrificial layer and selectively cuts off the InP etching stop layer.

[0021] Beneficial effects

[0022] In the present invention 0.53 Ga 0.47 The As absorber layer is lattice-matched to the InP substrate. During wet chemical etching of the InP substrate, the etching solution, caused by mismatch dislocation defects, is prevented from penetrating the InP etching stop layer and entering the absorber layer. This allows for minimal damage to the InP substrate and high precision removal.

[0023] The present invention introduces a dislocation barrier layer, which is used to block In x Ga 1-x The threading dislocations formed in the As composition graded absorption layer due to lattice mismatch also act as a potential barrier to block majority carriers, which is beneficial to reducing the dark current density and realizing a high-sensitivity visible-shortwave infrared wide-spectrum InGaAs detector.

[0024] By adjusting the In component in the high-In component InGaAs absorption layer, the present invention can freely adjust the response spectrum cutoff wavelength of the broadband InGaAs detector in the short-wave infrared band, thereby meeting the detection requirements of specific bands in different environments.

[0025] The photosensitive element structure of a wide-spectrum InGaAs detector of the present invention is applicable to existing InGaAs detector manufacturing processes. Furthermore, the photosensitive element structure of a monolithic InGaAs detector can achieve photon response across a wide visible-to-shortwave infrared spectrum, potentially enabling the realization of a miniaturized, highly sensitive, and low-power visible-to-shortwave infrared system, improving infrared imaging capabilities such as low-light-level night vision and hyperspectral imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of the photosensitive element of the wide-spectrum InGaAs detector of the present invention.

[0027] In the picture:

[0028] 1—InP corrosion stop layer;

[0029] 2—In 0.53 Ga 0.47 As absorption layer;

[0030] 3—In x Ga 1-x As component graded absorption layer;

[0031] 4—dislocation barrier;

[0032] 5—High In content InGaAs absorption layer;

[0033] 6—High In content InAlAs contact layer. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. It should be understood herein that, after reading the content taught by the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

[0035] Example 1

[0036] The purpose of this embodiment is to 0.6 Ga 0.4 As is used as the material for the high-In content InGaAs absorption layer to fabricate the photosensitive element of an InGaAs detector with a wide spectrum of room-temperature response spectrum covering 400-1900nm. The photosensitive element structure demonstrated in this embodiment is a back-illuminated mesa-type PIN structure. From bottom to top, it includes the following materials:

[0037] 1. N-type heavily doped InP corrosion stop layer, thickness is 10nm, doping concentration is 5×10 17 cm -3 This InP corrosion stop layer also serves as the N-type electrode contact layer.

[0038] 2. N-type lightly doped In 0.53 Ga 0.47 As absorption layer, thickness is 500nm, doping concentration is 1×10 16 cm -3 .

[0039] 3. N-type lightly doped In x Ga 1-x As composition graded absorption layer, thickness 800nm, x from N-type lightly doped In x Ga 1-x The As composition of the graded absorption layer increases linearly from 0.53 to 0.6 along the thickness direction from the bottom to the top, and the doping concentration is 1×10 16 cm -3 .

[0040] In this layer x Ga 1-x The As composition-graded absorption layer also serves as an epitaxial buffer layer.

[0041] 4. N-type lightly doped In 0.59 Al 0.41 As dislocation barrier layer with a thickness of 50 nm and a doping concentration of 1×10 16 cm -3 .

[0042] 5. N-type lightly doped In 0.6 Ga 0.4As absorption layer, thickness is 500nm, doping concentration is 1×10 16 cm -3 .

[0043] 6. P-type heavily doped In 0.59 Al 0.41 As contact layer, thickness is 500nm, doping concentration is 3×10 18 cm -3 The material is prepared by molecular beam epitaxy technology. The specific growth process is as follows:

[0044] (1) The InP(001) substrate was grown at a growth rate of 1 μm / h by preliminary growth. 0.53 Ga 0.47 As、In 0.6 Ga 0.4 As、In 0.59 Al 0.41 As substrate growth temperature, beam source furnace temperature, V / III ratio and other growth conditions; determine the N-type doping concentration to be 5×10 17 cm -3 The temperature of the doping source furnace of the InP etching stop layer is determined to be 1×10 16 cm -3 In 0.53 Ga 0.47 As absorption layer, In x Ga 1-x As composition graded absorption layer, In 0.59 Al 0.41 As dislocation barrier and In 0.6 Ga 0.4 The temperature of the doping source furnace of the As absorption layer is determined to be 3×10 18 cm -3 In 0.59 Al 0.41 The temperature of the doping source furnace for the As contact layer.

[0045] (2) After a single-side polished Epi-ready semi-insulating InP (100) substrate was deoxidized at 630 ° C for 6 minutes, a layer of In 0.53 Ga 0.47 The sacrificial layer is etched by As, and then the above-mentioned materials 1 to 6 are grown in sequence. The thickness, material type and doping concentration of each layer are the same as described above.

[0046] After the epitaxial growth is completed, the substrate temperature is lowered to below 300°C under the protection of As2 atmosphere, and the epitaxial material is removed.

[0047] The steps for preparing the photosensitive element are as follows:

[0048] (1) Fix one side of the epitaxial layer of the epitaxial material grown above to a quartz carrier by melting paraffin wax, place the quartz carrier in a grinder fixture, make one side of the InP substrate contact the polishing cloth, and use No. 303 corundum powder polishing liquid to mechanically polish and thin it to 50 μm. Further use No. 306 corundum powder polishing liquid to mechanically polish and thin it to 10 μm.

[0049] (2) The epitaxial wafer thinned by mechanical grinding in the previous step was cleaned with deionized water, dried with nitrogen, and immersed in a corrosion solution of hydrochloric acid: phosphoric acid: water = 1:3:3 to completely corrode the remaining 10 μm InP substrate. The corrosion solution has a great effect on the In 0.53 Ga 0.47 As corrosion selectively cuts off the sacrificial layer.

[0050] (3) The epitaxial wafer after the wet chemical etching in the previous step was cleaned with deionized water, dried with nitrogen, and then immersed in a corrosion solution of phosphoric acid: hydrogen peroxide: water = 1:5:5 to remove In 0.53 Ga 0.47 As etches the sacrificial layer, and the etching solution selectively stops the InP etching stop layer.

[0051] (4) Heat the quartz carrier to melt the paraffin, remove it and clean it to remove the residual paraffin.

[0052] After the above process is completed, a photosensitive element structure of a table-type visible-shortwave infrared wide-spectrum InGaAs detector with a spectral response covering 400-1900nm is obtained.

[0053] Example 2

[0054] The purpose of this embodiment is to 0.75 Ga 0.25 As is used as the material for the high-In content InGaAs absorption layer to fabricate the photosensitive element of an InGaAs detector with a wide spectrum of room temperature response spectrum covering 400-2300nm. The photosensitive element structure demonstrated in this embodiment is a back-illuminated planar NIN structure. From bottom to top, it includes the following materials:

[0055] 1. N-type heavily doped InP corrosion stop layer, thickness is 45nm, doping concentration is 1×10 18 cm -3 This InP corrosion stop layer also serves as the N-type electrode contact layer.

[0056] 2. N-type lightly doped In 0.53 Ga 0.47 As absorption layer, thickness is 650nm, doping concentration is 1×10 15 cm -3 .

[0057] 3. N-type lightly doped In x Ga 1-x As composition graded absorption layer, thickness 1100nm, x from N-type lightly doped In x Ga 1-x The As composition of the graded absorption layer increases linearly from 0.53 to 0.75 along the thickness direction from the bottom to the top, and the doping concentration is 1×10 15 cm -3 .

[0058] In this layer x Ga 1-x The As composition-graded absorption layer also serves as an epitaxial buffer layer.

[0059] 4. N-type lightly doped In 0.74 Al 0.26 As dislocation barrier layer with a thickness of 100 nm and a doping concentration of 1×10 15 cm -3 .

[0060] 5. N-type lightly doped In 0.75 Ga 0.25 As absorption layer, thickness is 650nm, doping concentration is 1×10 15 cm -3 .

[0061] 6. N-type lightly doped In 0.74 Al 0.26 As contact layer, thickness is 750nm, doping concentration is 1×10 15 cm -3 The material is prepared by molecular beam epitaxy technology. The specific growth process is as follows:

[0062] (1) The InP(001) substrate was grown at a growth rate of 1 μm / h by preliminary growth. 0.53 Ga 0.47 As、In 0.75 Ga 0.25 As、In 0.74 Al 0.26 As substrate growth temperature, beam source furnace temperature, V / III ratio and other growth conditions; determine the N-type doping concentration to be 1×10 18 cm -3 The temperature of the doping source furnace of the InP etching stop layer is determined to be 1×10 15 cm -3 In 0.53 Ga 0.47 As absorption layer, In x Ga 1-x As composition graded absorption layer, In0.74 Al 0.26 As dislocation barrier, In 0.75 Ga 0.25 As absorption layer and In 0.74 Al 0.26 The temperature of the doping source furnace for the As contact layer.

[0063] (2) After a single-side polished Epi-ready semi-insulating InP (100) substrate was deoxidized at 630 ° C for 6 minutes, a layer of In 0.53 Ga 0.47 The sacrificial layer is etched by As, and then the above-mentioned materials 1 to 6 are grown in sequence. The thickness, material type and doping concentration of each layer are the same as described above.

[0064] After the epitaxial growth is completed, the substrate temperature is lowered to below 300°C under the protection of As2 atmosphere, and the epitaxial material is removed.

[0065] The steps for preparing the photosensitive element are as follows:

[0066] (1) Fix one side of the epitaxial layer of the epitaxial material grown above to a quartz carrier by melting paraffin wax, place the quartz carrier in a grinder fixture, make one side of the InP substrate contact the polishing cloth, and use No. 303 corundum powder polishing liquid to mechanically polish and thin it to 50 μm. Further use No. 306 corundum powder polishing liquid to mechanically polish and thin it to 10 μm.

[0067] (2) The epitaxial wafer thinned by mechanical grinding in the previous step was cleaned with deionized water, dried with nitrogen, and immersed in a corrosion solution of hydrochloric acid: phosphoric acid: water = 1:3:3 to completely corrode the remaining 10 μm InP substrate. The corrosion solution has a great effect on the In 0.53 Ga 0.47 As corrosion selectively cuts off the sacrificial layer.

[0068] (3) The epitaxial wafer after the wet chemical etching in the previous step was cleaned with deionized water, dried with nitrogen, and then immersed in a corrosion solution of phosphoric acid: hydrogen peroxide: water = 1:5:5 to remove In 0.53 Ga 0.47 As etches the sacrificial layer, and the etching solution selectively stops the InP etching stop layer.

[0069] (4) Heat the quartz carrier to melt the paraffin, remove it and clean it to remove the residual paraffin.

[0070] After the above process is completed, a planar visible-shortwave infrared wide spectrum InGaAs detector with a spectral response covering 400-2300nm is obtained. In order to realize the function of the photodetector, it is also necessary to lightly dope the N-type InGaAs with a 0.74 Al 0.26The As contact layer is subjected to a P-type diffusion process to form a PIN junction. The diffusion source is Zn3As2, and the diffusion depth is 750nm.

[0071] Example 3

[0072] The purpose of this embodiment is to 0.83 Ga 0.13 As is used as the material for the high-In content InGaAs absorption layer to fabricate the photosensitive element of an InGaAs detector with a wide spectrum of room temperature response spectrum covering 400-2600nm. The photosensitive element structure demonstrated in this embodiment is a back-illuminated planar NIN structure. From bottom to top, it includes the following materials:

[0073] 1. N-type heavily doped InP corrosion stop layer, thickness is 100nm, doping concentration is 3×10 18 cm -3 This InP corrosion stop layer also serves as the N-type electrode contact layer.

[0074] 2. N-type lightly doped In 0.53 Ga 0.47 As absorption layer, thickness is 800nm, doping concentration is 5×10 16 cm -3 .

[0075] 3. N-type lightly doped In x Ga 1-x As composition graded absorption layer, thickness 1400nm, x from N-type lightly doped In x Ga 1-x The As composition of the graded absorption layer increases linearly from 0.53 to 0.83 along the thickness direction from the bottom to the top, and the doping concentration is 5×10 16 cm -3 .

[0076] In this layer x Ga 1-x The As composition-graded absorption layer also serves as an epitaxial buffer layer.

[0077] 4. N-type lightly doped InAs 0.64 P 0.36 The dislocation barrier layer has a thickness of 150 nm and a doping concentration of 5 × 10 16 cm -3 .

[0078] 5. N-type lightly doped In 0.83 Ga 0.17 As absorption layer, thickness is 800nm, doping concentration is 5×10 16 cm -3 .

[0079] 6. N-type lightly doped In 0.83 Al 0.17 As contact layer, thickness is 1000nm, doping concentration is 5×10 16 cm -3 The material is prepared by molecular beam epitaxy technology. The specific growth process is as follows:

[0080] (1) The InP(001) substrate was grown at a growth rate of 1 μm / h by preliminary growth. 0.53 Ga 0.47 As、InAs 0.64 P 0.36 、In 0.83 Ga 0.17 As、In 0.83 Al 0.17 As substrate growth temperature, beam source furnace temperature, V / III ratio and other growth conditions; the N-type doping concentration is determined to be 3×10 18 cm -3 The temperature of the doping source furnace of the InP etching stop layer is determined to be 5×10 16 cm -3 In 0.53 Ga 0.47 As absorption layer, In x Ga 1-x As composition graded absorption layer, InAs 0.64 P 0.36 Dislocation barrier layer, In 0.83 Ga 0.17 As absorption layer and In 0.83 Al 0.17 The temperature of the doping source furnace for the As contact layer.

[0081] (2) After a single-side polished Epi-ready semi-insulating InP (100) substrate was deoxidized at 630 ° C for 6 minutes, a layer of In 0.53 Ga 0.47 The sacrificial layer is etched by As, and then the above-mentioned materials 1 to 6 are grown in sequence. The thickness, material type and doping concentration of each layer are the same as described above.

[0082] After the epitaxial growth is completed, the substrate temperature is lowered to below 300°C under the protection of As2 atmosphere, and the epitaxial material is removed.

[0083] The steps for preparing the photosensitive element are as follows:

[0084] (1) Fix one side of the epitaxial layer of the epitaxial material grown above to a quartz carrier by melting paraffin wax, place the quartz carrier in a grinder fixture, make one side of the InP substrate contact the polishing cloth, and use No. 303 corundum powder polishing liquid to mechanically polish and thin it to 50 μm. Further use No. 306 corundum powder polishing liquid to mechanically polish and thin it to 10 μm.

[0085] (2) The epitaxial wafer thinned by mechanical grinding in the previous step was cleaned with deionized water, dried with nitrogen, and immersed in a corrosion solution of hydrochloric acid: phosphoric acid: water = 1:3:3 to completely corrode the remaining 10 μm InP substrate. The corrosion solution has a great effect on the In 0.53 Ga 0.47 As corrosion selectively cuts off the sacrificial layer.

[0086] (3) The epitaxial wafer after the wet chemical etching in the previous step was cleaned with deionized water, dried with nitrogen, and then immersed in a corrosion solution of phosphoric acid: hydrogen peroxide: water = 1:5:5 to remove In 0.53 Ga 0.47 As etches the sacrificial layer, and the etching solution selectively stops the InP etching stop layer.

[0087] (4) Heat the quartz carrier to melt the paraffin, remove it and clean it to remove the residual paraffin.

[0088] After the above process is completed, a planar visible-shortwave infrared wide spectrum InGaAs detector with a spectral response covering 400-2600nm is obtained. In order to realize the function of the photodetector, it is also necessary to lightly dope the N-type InGaAs with a 0.83 Al 0.17 The As contact layer is subjected to a P-type diffusion process to form a PIN junction. The diffusion source is Zn3As2, and the diffusion depth is 1000nm.

Claims

1. A photosensitive element structure of a wide spectrum InGaAs detector, comprising an InP etching cutoff layer (1), an In 0.53 Ga 0.47 As absorption layer (2), In x Ga 1-x As composition graded absorption layer (3), dislocation barrier layer (4), high In composition InGaAs absorption layer (5), high In composition InAlAs contact layer (6); characterized in that: The photosensitive element structure is composed of InP corrosion cut-off layer (1), In 0.53 Ga 0.47 As absorption layer (2), In x Ga 1-x As composition graded absorption layer (3), dislocation barrier layer (4), high In composition InGaAs absorption layer (5) and high In composition InAlAs contact layer (6); In x Ga 1-x The x of the As composition gradient absorption layer (3) is from the In x Ga 1-x The As composition gradient absorption layer (3) linearly gradients from 0.53 to a from the lower end to the upper end, and 0.53<a≤1.

2. The photosensitive element structure of a wide spectrum InGaAs detector according to claim 1, characterized in that: The thickness of the InP corrosion stop layer (1) is 10-100 nm, the doping type is N type, and the doping concentration is 5×10 17 -5×10 18 cm -3 .

3. The photosensitive element structure of a wide spectrum InGaAs detector according to claim 1, characterized in that: In 0.53 Ga 0.47 The As absorption layer (2) has a thickness of 500-800 nm, a weak N-type doping type, and a doping concentration of 1×10 15 -5×10 16 cm -3 .

4. The photosensitive element structure of a wide spectrum InGaAs detector according to claim 1, characterized in that: In x Ga 1-x The thickness of the As composition graded absorption layer (3) is 800-1400 nm, the doping type is weak N-type, and the doping concentration is 1×10 15 -5×10 16 cm -3 .

5. The photosensitive element structure of a wide spectrum InGaAs detector according to claim 1, characterized in that: The dislocation barrier layer (4) is x Ga 1-x The upper end of the As composition graded absorption layer (3) is lattice-matched InAlAs or InAsP, with a thickness of 50-150 nm, a weak N-type doping type, and a doping concentration of 1×10 15 -5×10 16 cm -3 .

6. The photosensitive element structure of a wide spectrum InGaAs detector according to claim 1, characterized in that: The high-In component InGaAs absorption layer (5) is lattice-matched with the dislocation barrier layer (4), has a thickness of 500-800 nm, a weak N-type doping type, and a doping concentration of 1×10 15 -5×10 16 cm -3 .

7. The photosensitive element structure of a wide spectrum InGaAs detector according to claim 1, characterized in that: The thickness of the high-In content InAlAs contact layer (6) is 500-1000 nm, the doping type is P type, and the doping concentration is 3×10 18 -5×10 18 cm -3 ; or the doping type is weak N-type, and the doping concentration is 1×10 15 -5×10 16 cm -3 .

8. A method for preparing the photosensitive element structure of the wide spectrum InGaAs detector according to claim 1, characterized in that The following steps are involved: 1) placing an InP substrate into a reaction chamber and performing a heating pretreatment on the InP substrate; 2) In is grown on an InP substrate using epitaxial growth technology 0.53 Ga 0.47 As corrodes the sacrificial layer; 3) In 0.53 Ga 0.47 Epitaxially growing the InP corrosion stop layer (1) on the As corrosion sacrificial layer; 4) epitaxially growing the InP corrosion stop layer (1) 0.53 Ga 0.47 As absorption layer (2); 5) In the 0.53 Ga 0.47 The In is epitaxially grown on the As absorption layer (2) x Ga 1-x As composition graded absorption layer (3); 6) In the x Ga 1-x Epitaxially growing the dislocation barrier layer (4) on the As composition graded absorption layer (3); 7) epitaxially growing the high-In content InGaAs absorption layer (5) on the dislocation barrier layer (4); 8) epitaxially growing the high In content InAlAs contact layer (6) on the high In content InGaAs absorption layer (5); 9) Thin the InP substrate to less than 10 μm by mechanical grinding, remove the remaining InP substrate with a mixed solution of hydrochloric acid and phosphoric acid, and 0.53 Ga 0.47 As corrosion sacrificial layer selectively cuts off; 10) Use phosphoric acid and hydrogen peroxide mixed solution to corrode and remove In 0.53 Ga 0.47 As etches the sacrificial layer and selectively cuts off the InP etching stop layer (1).

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