Extremely low noise Geiger avalanche single photon detector and preparation method thereof

Abstract

The invention discloses an extremely-low-noise Geiger avalanche single-photon detector which is characterized in that an indium phosphide buffer layer (2), an N + type indium phosphide contact layer (3), an indium-aluminum-arsenic transition layer (4), an indium-aluminum-arsenic-antimony multiplication layer (5), a P + type indium-aluminum-arsenic-antimony charge layer (6), an indium-gallium-arsenic protection layer (7), an indium-gallium-arsenic-phosphorus absorption layer (8) and an indium-gallium-arsenic top layer (9) are sequentially arranged on a semi-insulating indium phosphide substrate (1) in an epitaxial manner by adopting a molecular beam epitaxy process; forming an indium gallium arsenic phosphorus / indium aluminum arsenic antimony heterojunction material; an in-situ selective area P-type doping process is adopted, a P + type doped region (10) is formed in an indium gallium arsenic top layer (9), a step-type groove is etched, a passivation film (11) is deposited on the surface, a P electrode (12) connected with the indium gallium arsenic top layer (9) and an N electrode (13) connected with an N + type indium phosphide contact layer (3) are prepared, and an antireflection film (14) is prepared in a light inlet hole. And forming a Geiger avalanche chip structure with plane-mesa composite and PN electrode coplanar.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor optoelectronic devices, and relates to an extremely low noise Geiger avalanche single photon detector and a preparation method thereof, specifically an extremely low noise Geiger avalanche single photon detector based on InGaAsP / InAlAsSb heterojunction material and a preparation method thereof. Background Art

[0002] The Geiger avalanche single-photon detector is developed based on an avalanche photodiode (APD) working in Geiger mode. The difference between an avalanche photodiode and a pn junction photodiode is that it can work at a higher bias voltage, thereby obtaining a higher current gain. The APD absorbs photons to generate electron-hole pairs, which gain enough energy in a strong electric field and generate more electron-hole pairs after collision ionization with the lattice. Repeating this process will produce a large number of electron-hole pairs, that is, an "avalanche" phenomenon occurs, and the photocurrent will increase exponentially.

[0003] The Geiger-mode APD operates at a voltage higher than the avalanche breakdown voltage, which greatly increases the rate of electron-hole pairs generated by collision ionization, forming a macroscopically detectable photocurrent and a continuous avalanche state. The APD equivalent resistance will provide a negative feedback. The increase in photocurrent will increase the voltage drop of the APD equivalent resistance, thereby eliminating part of the bias voltage, causing the bias voltage on the APD to decrease, forming a balance process. Therefore, after a single photon absorbed by the Geiger-mode APD undergoes collision ionization, it can produce a chain reaction of avalanche amplification, thereby achieving single-photon detection.

[0004] Geiger avalanche single photon detector has a high photocurrent gain, but also has high noise. The noise sources include hot carrier triggering caused by temperature effect and tunneling carrier triggering caused by electric field effect. The former is related to the essential characteristics of the material such as the bandgap width, and the latter is related to factors such as the defect density of the material and the electric field distribution of the chip.

[0005] The existing 1.06μm near-infrared Geiger avalanche single-photon detectors are mainly developed based on InGaAs / InP materials. InGaAs materials, as absorption zone materials, have a smaller bandgap width, resulting in larger thermal noise. InP materials, as multiplication zone materials, have a larger collision ionization coefficient, resulting in larger avalanche excess noise. The noise of InGaAs / InP Geiger avalanche single-photon detectors is relatively large. On the one hand, due to the need for a lower cooling temperature to suppress thermal noise, the volume and power consumption are relatively large, and the application field is narrower than that of silicon-based Geiger avalanche single-photon detectors. On the other hand, due to the large background noise, the after-pulse effect is obvious, making it difficult to apply to high-precision ranging, high-rate photon counting and other application fields. Summary of the invention

[0006] (I) Purpose of the invention

[0007] The purpose of the present invention is to propose an extremely low noise Geiger avalanche single-photon detector based on InGaAsP / InAlAsSb heterojunction material and a preparation method thereof, so as to solve the problems existing in the current InGaAs / InP Geiger avalanche single-photon detector, such as high thermal noise due to small bandgap width of absorption zone material, high avalanche excess noise due to high K factor of multiplication zone material, and high false alarm noise caused by pseudo-counting and miscounting of a single photosensitive element. For a laser wavelength of 1.06μm, single-photon detection with extremely low dark count rate is realized, so as to meet the application requirements of ultra-long-distance high-resolution laser ranging and large-data-volume low-bit-error-rate laser communication.

[0008] (II) Technical solution

[0009] In order to solve the above technical problems, the present invention provides an extremely low noise Geiger avalanche single photon detector. The molecular beam epitaxy process is used to sequentially epitaxially grow an indium phosphide buffer layer 2, an N+ type indium phosphide contact layer 3, an indium aluminum arsenic transition layer 4, an indium aluminum arsenic antimony multiplication layer 5, a P+ type indium aluminum arsenic antimony charge layer 6, an indium gallium arsenic protective layer 7, an indium gallium arsenic phosphorus absorption layer 8, and an indium gallium arsenic top layer 9 on a semi-insulating indium phosphide substrate 1 to form an indium gallium arsenic phosphorus / indium aluminum arsenic antimony heterojunction material; an in-situ selective P-type doping process is used to form a P+ type doping region 10 in the indium gallium arsenic top layer 9, a step-type groove is etched, a passivation film 11 is deposited on the surface, a P electrode 12 connected to the indium gallium arsenic top layer 9 and an N electrode 13 connected to the N+ type indium phosphide contact layer 3 are prepared, and an antireflection film 14 is prepared in the light intake hole to form a Geiger avalanche chip structure with a plane-table composite and a PN electrode coplanar.

[0010] Among them, in the Geiger avalanche chip structure, the step-type groove has three etching steps, the first etching step reaches the inside of the InGaAsP absorption layer 8, the second etching step reaches the N+ type InP contact layer 3, and the third etching step reaches the inside of the semi-insulating InP substrate 1.

[0011] The detector further includes: a device structure in which four photosensitive elements serve as the same photosensitive area to detect laser signals simultaneously.

[0012] Among them, the P electrode of each photosensitive element is first connected to a quenching resistor 15, and then connected to a P electrode lead pad 16. At the same time, the N electrode of each photosensitive element is connected together to form a common electrode, and connected to the N electrode lead pad 17 on both sides.

[0013] Among them, the four photosensitive elements work and output independently through the matching readout circuit. The subsequent processing circuit counts the photons of the output data to eliminate false alarm noise and identify signal photons.

[0014] The present invention also provides a method for preparing an extremely low noise Geiger avalanche single photon detector, which comprises the following process:

[0015] S1: Preparation of InGaAsP / InAlAsSb heterojunction material based on 3-inch semi-insulating InP substrate wafer;

[0016] S2: Preparation of Geiger avalanche chip structure with planar-table composite and PN electrode coplanar characteristics;

[0017] S3: A Geiger avalanche single-photon device structure was prepared based on a multi-component composite noise reduction working mechanism in which four photosensitive elements simultaneously detect laser signals in the same photosensitive area.

[0018] In process S1, a molecular beam epitaxy process is used to epitaxially grow the following on a 3-inch semi-insulating indium phosphide substrate 1: an indium phosphide buffer layer 2 with a thickness of 1 μm, a layer with a thickness of 1 μm and a doping concentration of 1E18 cm -3 N+ type indium phosphide contact layer 3, indium aluminum arsenic transition layer 4 with a thickness of 0.2μm, indium aluminum arsenic antimony multiplication layer 5 with a thickness of 0.2μm and a doping concentration of 1E17cm -3 A P+ type InAsSb charge layer 6, a 0.1μm thick InGaAs protective layer 7, a 2μm thick InGaAs phosphorus absorption layer 8, and a 3μm thick InGaAs top layer 9 form an InGaAs phosphorus / InAsSb heterojunction material.

[0019] In process S2, an in-situ selective P-type doping process is used to form a P+ doping region 10 in the InGaAs top layer 9; a step-type groove is etched around the P+ doping region 10 of the Geiger avalanche chip structure by photolithography and ICP etching processes, which is concentric with the P+ doping region 10, and the first etching step of the step-type groove reaches the inside of the InGaAs phosphide absorption layer 8, the second etching step reaches the N+ indium phosphide contact layer 3, and the third etching step reaches the inside of the semi-insulating indium phosphide substrate 1; a silicon nitride / silicon dioxide passivation film 11 is deposited on the surface of the step-type groove of the Geiger avalanche chip structure by photolithography and atomic layer deposition processes; a P electrode 12 connected to the InGaAs top layer 9 is first prepared by photolithography, magnetron sputtering and electron beam evaporation processes, and then an N electrode 13 connected to the N+ indium phosphide contact layer 3 is prepared; a silicon nitride anti-reflection film 14 is prepared in the light inlet by PECVD dielectric film deposition process.

[0020] In process S3, a metal film deposition process is used to prepare a quenching resistor 15 based on lithium niobate alloy on the outside of the P electrode of each photosensitive element, and a P electrode lead-out pad 16 is led out, the N electrodes of each photosensitive element are connected together to form a common electrode, and the N electrode lead-out pads 17 are connected on both sides.

[0021] (III) Beneficial effects

[0022] The extremely low noise Geiger avalanche single photon detector and its preparation method provided by the above technical solution have the following beneficial effects:

[0023] (1) The detector uses semi-insulating indium phosphide as the substrate, and epitaxially grows indium gallium arsenic phosphide / indium aluminum arsenic antimony heterojunction materials with specific functional structures. Based on a new Geiger avalanche structure with planar-table composite and coplanar PN electrodes, it adopts a multi-composite noise reduction mechanism in which multiple photosensitive elements work simultaneously, effectively reducing the noise of the Geiger avalanche single-photon detector, solving the problem of suppressing various noises such as false alarm noise, thermal noise, and avalanche excess noise, achieving extremely low-noise single-photon detection, improving the optoelectronic performance indicators of the device, and improving the applicability of the device on various platforms.

[0024] (2) The detector uses four photosensitive elements as the same photosensitive area to perform photon counting coincidence detection, which effectively eliminates the false counts and miscounts that have a high probability of occurring in a single photosensitive element, solving the problem of high false alarm noise; the molecular beam epitaxy process is used, and the indium gallium arsenic phosphide quaternary compound is used as the absorption area material to improve the quantum efficiency of the 1.06μm laser wavelength, increase the bandgap width of the material, and use the indium gallium arsenic protective layer to isolate the influence of aluminum, antimony and other elements on the indium gallium arsenic phosphide absorption area, solving the problem of high thermal noise; the molecular beam epitaxy process is used, and the indium aluminum arsenic antimony quaternary compound is used as the multiplication area material to achieve low k factor multiplication, and the indium aluminum arsenic transition layer is used for band regulation and electric field regulation, reducing the interface potential barrier and smoothing the electric field jump, solving the problem of high avalanche excess noise. In this way, the noise of the Geiger avalanche single photon detector is effectively suppressed, solving the application bottlenecks such as high false alarm rate, high cooling requirements, and low quantum efficiency.

[0025] (3) The detector innovatively proposes an InGaAsP / InAlAsSb heterojunction material based on a specific functional structure, combined with a planar-table composite and PN electrode coplanar Geiger avalanche chip structure, and uses a multi-composite noise reduction working mechanism to simultaneously detect laser signals in the same photosensitive area using four photosensitive elements, thus realizing the design and preparation of an extremely low noise Geiger avalanche single-photon detector.

[0026] (4) The present invention can provide a reference for designing and preparing extremely low noise Geiger avalanche single photon detectors for ultra-long distance high-resolution laser ranging, large data volume low bit error rate laser communication and other systems. The InGaAsP / InAlAsSb heterojunction Geiger avalanche single photon detector prepared according to the present invention realizes single photon detection at an ultra-low dark count rate level of hundreds of hertz, and the method is feasible. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the material structure of the extremely low noise Geiger avalanche single-photon detector.

[0028] Figure 2 Schematic diagram of the chip structure of the extremely low noise Geiger avalanche single-photon detector.

[0029] Figure 3Schematic diagram of the device structure of the extremely low noise Geiger avalanche single-photon detector. DETAILED DESCRIPTION

[0030] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below in conjunction with the drawings and examples.

[0031] The present invention proposes an extremely low noise Geiger avalanche single photon detector based on InGaAsP / InAlAsSb heterojunction material. In order to effectively reduce noise, a chip structure design of multi-element composite noise reduction is adopted. Four independently working photosensitive elements simultaneously detect laser signals. At the same time, at least three pixel output counts are identified as signal photons, thereby completing the identification of signal photons and the elimination of false alarm noise. InGaAsP quaternary compounds are used instead of InGaAs as the absorption zone material, and the advantage of the larger bandgap width of InGaAsP can be used to further reduce thermal noise. Under the same cooling conditions, the detection of laser signals by the detector is realized. In addition to achieving lower noise at lower temperature, the composition ratio of the quaternary compound can be changed in a targeted manner to achieve high quantum efficiency absorption of specific near-infrared laser wavelengths such as 1.06μm; using indium aluminum arsenic antimony quaternary compounds instead of indium phosphide as the multiplication zone material, and utilizing its low K factor characteristics, it can increase the ratio of the electron-hole carrier multiplication probabilities and reduce the avalanche excess noise caused by the recombination effect of electron-hole pairs, thereby solving noise sources such as false alarm noise, thermal noise, and avalanche excess noise, ensuring the realization of single-photon detection with extremely low noise below 100 Hz.

[0032] Reference Figure 1 and Figure 2 As shown, the ultra-low noise Geiger avalanche single-photon detector of this embodiment adopts a molecular beam epitaxy process. On a semi-insulating indium phosphide substrate 1, an indium phosphide buffer layer 2, an N+ type indium phosphide contact layer 3, an indium aluminum arsenic transition layer 4, an indium aluminum arsenic antimony multiplication layer 5, a P+ type indium aluminum arsenic antimony charge layer 6, an indium gallium arsenic protection layer 7, an indium gallium arsenic phosphorus absorption layer 8, and an indium gallium arsenic top layer 9 are sequentially epitaxially grown to form an indium gallium arsenic phosphorus / indium aluminum arsenic antimony heterojunction material; an in-situ selective P-type doping process is adopted to form a P+ type doping region 10 in the indium gallium arsenic top layer 9, a step-type groove is etched, a passivation film 11 is deposited on the surface, a P electrode 12 connected to the indium gallium arsenic top layer 9, an N electrode 13 connected to the N+ type indium phosphide contact layer 3 are prepared, and an anti-reflection film 14 is prepared in the light inlet hole to form a Geiger avalanche chip structure with the characteristics of plane-table composite and PN electrode coplanarity.

[0033] Furthermore, if Figure 3As shown in the device structure of the detector, four photosensitive elements serve as the same photosensitive area to detect laser signals at the same time. The P electrode of each photosensitive element is first connected to a quenching resistor 15, and then connected to a P electrode lead pad 16. At the same time, the N electrode of each photosensitive element is connected together to form a common electrode, and connected to the N electrode lead pad 17 on both sides.

[0034] Among them, the four photosensitive elements A, B, C, and D serve as the same photosensitive area (i.e. within the dotted line range) and detect laser signals at the same time. The four photosensitive elements respectively realize independent operation and independent output through the matching readout circuits. The subsequent processing circuit performs photon counting on the output data to eliminate false alarm noise and identify signal photons.

[0035] Based on the above-mentioned detector structure, the preparation method of the ultra-low noise Geiger avalanche single-photon detector in this embodiment prepares an InGaAsP / InAlAsSb heterojunction material with a specific functional structure based on a 3-inch semi-insulating InP substrate wafer, prepares a Geiger avalanche chip structure with the characteristics of planar-table composite and PN electrode coplanarity, and prepares a Geiger avalanche single-photon detector structure with a multi-composite noise reduction working mechanism based on four photosensitive elements as the same photosensitive area to simultaneously detect laser signals.

[0036] Specifically, the method of this embodiment includes the following steps:

[0037] In the first step, a 1 μm thick indium phosphide buffer layer 2 with a doping concentration of 1E18 cm-1 and a thickness of 1 μm are sequentially grown on a 3-inch semi-insulating indium phosphide substrate 1 using a molecular beam epitaxy process. -3 N+ type indium phosphide contact layer 3, indium aluminum arsenic transition layer 4 with a thickness of 0.2μm, indium aluminum arsenic antimony multiplication layer 5 with a thickness of 0.2μm and a doping concentration of 1E17cm -3 A P+ type InAlAsSb charge layer 6, a 0.1 μm thick InGaAs protective layer 7, a 2 μm thick InGaAs phosphide absorption layer 8, and a 3 μm thick InGaAs top layer 9 are formed to form an InGaAsP / InAlAsSb heterojunction material with a specific functional structure, as shown in the attached Figure 1 shown.

[0038] In the second step, a P+ type doping region 10 is formed in the InGaAs top layer 9 by using an in-situ selective P type doping process, as shown in the attached Figure 2 shown.

[0039] In the third step, a step-type trench is etched around the P+ doped region 10 of the Geiger avalanche chip structure by using photolithography and ICP etching processes. The step-type trench is concentric with the P+ doped region 10. The first step of the step-type trench etching reaches the inside of the InGaAsP absorption layer 8, the second step of the step etching reaches the N+ InP contact layer 3, and the third step of the step etching reaches the inside of the semi-insulating InP substrate 1. Figure 2 shown.

[0040] The fourth step is to deposit a silicon nitride / silicon dioxide passivation film 11 on the surface of the step-shaped groove of the Geiger avalanche chip structure by using photolithography and atomic layer deposition technology, as shown in the attached Figure 2 shown.

[0041] In the fifth step, a P electrode 12 connected to the InGaAs top layer 9 is prepared by photolithography, magnetron sputtering and electron beam evaporation, and then an N electrode 13 connected to the N+ type InP contact layer 3 is prepared. Figure 2 shown.

[0042] Step 6: Using PECVD dielectric film deposition process, prepare silicon nitride antireflection film 14 in the light inlet hole, as shown in the attached Figure 2 shown.

[0043] In the seventh step, a quenching resistor 15 based on lithium niobate alloy is prepared on the outside of the P electrode of each photosensitive element by using a metal film deposition process, and a P electrode lead pad 16 is led out, as shown in the attached figure. Figure 3 shown.

[0044] In the eighth step, the N electrodes of each photosensitive element are connected together to form a common electrode by using a metal film deposition process, and the N electrode lead pads 17 are connected on both sides, as shown in the attached figure. Figure 3 shown.

[0045] After testing and evaluation, the InGaAsP / InAlAsSb Geiger avalanche single-photon detector prepared according to the method for preparing an extremely low noise Geiger avalanche single-photon detector based on InGaAsP / InAlAsSb heterojunction material described in the present invention achieved extremely low noise detection with a dark count rate of less than 100 Hz, and its performance was better than that of traditional devices.

[0046] It can be seen from the above technical scheme that the present invention uses a semi-insulating indium phosphide substrate as a substrate, epitaxially grows an indium gallium arsenic phosphide / indium aluminum arsenic antimony heterojunction material with a specific functional structure, based on a new Geiger avalanche structure with planar-table composite and PN electrode coplanarity, and adopts a multi-component composite noise reduction mechanism with multiple photosensitive elements working simultaneously, which effectively reduces the noise of the Geiger avalanche single-photon detector, and has the following significant characteristics:

[0047] First, four photosensitive elements are used as the same photosensitive area to perform photon counting coincidence detection, which effectively eliminates false counts and miscounts and solves the problem of high false alarm noise;

[0048] Second, the quaternary compound of InGaAsP is used as the absorption zone material, the composition ratio of the quaternary compound is adjusted to improve the quantum efficiency of the 1.06μm laser wavelength, and the influence of elements such as aluminum and antimony on the absorption zone of InGaAsP is isolated through the InGaAs protective layer to solve the problem of high thermal noise.

[0049] The third is to use indium aluminum arsenic antimony quaternary compounds as the multiplication zone material, combined with indium aluminum arsenic transition layers, to achieve low k factor multiplication through energy band regulation engineering and electric field distribution adjustment, and solve the problem of high avalanche excess noise.

[0050] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An extremely low noise Geiger avalanche single photon detector, characterized in that: By using a molecular beam epitaxy process, an indium phosphide buffer layer (2), an N+ type indium phosphide contact layer (3), an indium aluminum arsenide transition layer (4), an indium aluminum arsenide antimony multiplication layer (5), a P+ type indium aluminum arsenide antimony charge layer (6), an indium gallium arsenic protective layer (7), an indium gallium arsenic phosphorus absorption layer (8), and an indium gallium arsenic top layer (9) are sequentially epitaxially grown on a semi-insulating indium phosphide substrate (1) to form an indium gallium arsenic phosphorus / indium aluminum arsenic antimony heterojunction material; An in-situ selective P-type doping process is adopted to form a P+ type doping area (10) in an InGaAs top layer (9), a step-type groove is etched, a passivation film (11) is deposited on the surface, a P electrode (12) connected to the InGaAs top layer (9) and an N electrode (13) connected to an N+ type InP contact layer (3) are prepared, and an anti-reflection film (14) is prepared in the light-entry hole, thereby forming a Geiger avalanche chip structure with a planar-table composite and coplanar PN electrodes.

2. The extremely low noise Geiger avalanche single photon detector according to claim 1, characterized in that: In the Geiger avalanche chip structure, the step-type groove has three etching steps, the first etching step reaches the inside of the indium gallium arsenic phosphide absorption layer (8), the second etching step reaches the N+ type indium phosphide contact layer (3), and the third etching step reaches the inside of the semi-insulating indium phosphide substrate (1).

3. The extremely low noise Geiger avalanche single photon detector according to claim 2, characterized in that: Also includes: Device structure: four photosensitive elements act as the same photosensitive area to detect laser signals simultaneously.

4. The extremely low noise Geiger avalanche single photon detector according to claim 3, characterized in that: The P electrode of each photosensitive element is first connected to a quenching resistor (15), and then connected to a P electrode lead pad (16). At the same time, the N electrodes of each photosensitive element are connected together to form a common electrode, and connected to N electrode lead pads (17) on both sides.

5. The extremely low noise Geiger avalanche single photon detector according to claim 4, characterized in that: The four photosensitive elements work and output independently through the matching readout circuit. The subsequent processing circuit counts the photons of the output data to eliminate false alarm noise and identify signal photons.

6. A method for preparing the extremely low noise Geiger avalanche single photon detector according to claim 5, characterized in that: The process includes: S1: Preparation of InGaAsP / InAlAsSb heterojunction material based on 3-inch semi-insulating InP substrate wafer; S2: Preparation of Geiger avalanche chip structure with planar-table composite and PN electrode coplanar characteristics; S3: A Geiger avalanche single-photon device structure was prepared based on a multi-component composite noise reduction working mechanism in which four photosensitive elements simultaneously detect laser signals in the same photosensitive area.

7. The preparation method according to claim 6, characterized in that: In process S1, a molecular beam epitaxy process is used to epitaxially grow the following on a 3-inch semi-insulating indium phosphide substrate (1): an indium phosphide buffer layer (2) with a thickness of 1 μm, a layer with a thickness of 1 μm and a doping concentration of 1E18 cm -3 N+ type indium phosphide contact layer (3), indium aluminum arsenic transition layer (4) with a thickness of 0.2 μm, indium aluminum arsenic antimony multiplication layer (5) with a thickness of 0.8 μm, and a doping concentration of 1E17 cm -3 A P+ type indium aluminum arsenic antimony charge layer (6), an indium gallium arsenic protective layer (7) with a thickness of 0.1 μm, an indium gallium arsenic phosphorus absorption layer (8) with a thickness of 2 μm, and an indium gallium arsenic top layer (9) with a thickness of 3 μm, forming an indium gallium arsenic phosphorus / indium aluminum arsenic antimony heterojunction material.

8. The preparation method according to claim 7, characterized in that: In process S2, an in-situ selective P-type doping process is used to form a P+ type doping region (10) in the InGaAs top layer (9); a photolithography and ICP etching process is used to etch a step-type groove around the P+ type doping region (10) of the Geiger avalanche chip structure, which is concentric with the P+ type doping region (10), wherein the first etching step of the step-type groove reaches the inside of the InGaAsP absorption layer (8), the second etching step reaches the N+ type InP contact layer (3), and the third etching step reaches the inside of the semi-insulating InP substrate (1).

9. The preparation method according to claim 8, characterized in that: In process S2, a silicon nitride / silicon dioxide passivation film (11) is deposited on the surface of the step-shaped groove of the Geiger avalanche chip structure by using photolithography and atomic layer deposition processes; a P electrode (12) connected to the indium gallium arsenide top layer (9) is first prepared by using photolithography, magnetron sputtering and electron beam evaporation processes, and then an N electrode (13) connected to the N+ type indium phosphide contact layer (3) is prepared; and a silicon nitride anti-reflection film (14) is prepared in the light inlet hole by using a PECVD dielectric film deposition process.

10. The preparation method according to claim 9, characterized in that: In process S3, a metal film deposition process is used to prepare a quenching resistor (15) based on a lithium niobate alloy on the outside of the P electrode of each photosensitive element, and a P electrode lead-out pad (16) is led out, and the N electrodes of each photosensitive element are connected together to form a common electrode, and the N electrode lead-out pads (17) are connected on both sides.

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