Manufacturing method of single-photon avalanche photodetector linear array

Abstract

The invention discloses a manufacturing method of a single-photon avalanche photodetector linear array, relates to the technical field of detector linear arrays, and aims to solve the problems of extremely low monolithic integration yield and high blind pixel rate of existing large array detectors such as linear arrays and area arrays. The method comprises the following steps: firstly, preparing a ceramic substrate, and sintering a plurality of groups of SPAD chip units which are distributed at equal intervals on the ceramic substrate, so that the plurality of groups of SPAD chip units which are distributed at equal intervals form a linear array unit; s2, preparing a base, welding a group of U-shaped bracket bases, and sintering a group of linear array units at the upper ends of the bottom surfaces of the U-shaped bracket bases; s3, a beam splitter is installed, specifically, the beam splitter is sintered in a base of the U-shaped support, and the beam splitter is obliquely installed at the diagonal position of the U-shaped support; and S4, installation is completed, and the other linear array unit is sintered to the side face of the U-shaped support base to complete installation. Therefore, the effects of reducing the crosstalk between the pixels and reducing the blind pixel rate are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of detector linear arrays, and in particular to a method for manufacturing a single-photon avalanche photoelectric detector linear array. Background Art

[0002] Single-photon detectors and their arrays have very wide applications in the near-infrared band, including optical time-domain reflectometry, quantum communication, laser detection and ranging system (LADAR), weak fluorescence research in biology and DNA analysis and semiconductor device material characterization. Geiger-mode InGaAs / InP SPAD has the advantages of high reliability, low noise, small size, easy integration and low power consumption. It is the preferred solution for single-photon detection in the near-infrared band at room temperature. Even with a carefully designed structure and well-controlled operating conditions, the performance of InGaAs / InP SPADs is still limited by the quality of InGaAs / InP material growth. The quality of InGaAs and InP materials in terms of defect state density is much worse than that of Si. The process infrastructure of InGaAs and InP materials also lags behind Si, which has been developed for more than 20 years.

[0003] A laser radar array receiver front-end readout integrated circuit with application number CN201710482621.1 adopts a planar array photoelectric converter module to receive and process optical signals in parallel, does not require a scanning mechanism, has a wide detection range, can receive pulse echo signals at any four adjacent positions, and the receiver readout integrated circuit outputs four analog voltages. The receiver is compatible with traditional 4-quadrant or 8-quadrant laser radar receivers and has good adaptability.

[0004] The above-mentioned existing technical solutions have the following defects: currently, due to the high defect state density, for large array detectors, such as linear arrays and planar arrays, the monolithic integration yield is extremely low and the blind pixel rate is high. In addition, as the array scale increases, the array pixels cannot be well isolated, and the crosstalk problem between pixels has become a key factor restricting the resolution performance of large-scale SPAD detection arrays. Summary of the invention

[0005] The purpose of the present invention is to provide a method for manufacturing a single-photon avalanche photodetector linear array which reduces crosstalk between pixels and blind pixel rate, thereby manufacturing a larger-scale SPAD array with higher resolution.

[0006] To achieve the above object, the present invention provides the following technical solutions: A method for manufacturing a single-photon avalanche photoelectric detector linear array, the method is as follows: S1: Linear array unit preparation: first prepare a ceramic substrate, and sinter multiple groups of SPAD chip units with equal spacing on the ceramic substrate, so that the multiple groups of SPAD chip units with equal spacing form a linear array unit; A1: The SPAD chip unit consists of a single SPAD chip unit, a conductive gold wire and a gold pad. Each SPAD chip unit is electrically connected through the conductive gold wire and the gold pad. S2: prepare a base, weld a set of U-shaped bracket bases, and sinter a set of linear array units on the upper end of the bottom surface of the U-shaped bracket base; S3: Beam splitter installation: prepare a group of beam splitters, sinter the beam splitters in the base of the U-shaped bracket, and install the beam splitters at an angle at the diagonal position of the U-shaped bracket; S4: Complete the installation and sinter another line array unit to the side of the U-shaped bracket base to complete the installation.

[0007] Furthermore, the ceramic substrate in S1 is a substrate with high strength and high thermal conductivity, and the ceramic substrate is one of aluminum oxide (Al2O3), aluminum nitride (AlN) or silicon carbide (SiC).

[0008] Furthermore, a certain amount of space is reserved between each SPAD unit in A1 and its adjacent SPAD unit, and the distance between two SPAD pixels is 100-400 μm.

[0009] Furthermore, the U-shaped bracket base in S2 is made of a material with excellent thermal conductivity, and the material of the U-shaped bracket base is copper.

[0010] Furthermore, the beam splitter in S3 is used to split the incident light beam into two beams of transmission and reflection with a certain light intensity ratio, and the beam splitter adopts a neutral beam splitter with a transmission and reflection ratio of 50 / 50.

[0011] Furthermore, the beam splitter in S3 is made of glass or metal, and the shape of the beam splitter is round or square.

[0012] Furthermore, the tilt angle of the beam splitter in S3 is specifically that the film layer forms an angle of 45° with the bottom surface.

[0013] Furthermore, the linear array unit in S4 is sintered to a side surface that can receive the light reflected by the beam splitter, and the sintering position of the side linear array unit depends on the positions of the transmitted light and the reflected light of the beam splitter. The position where it receives the reflected light after being incident on the beam splitter is staggered by half the SPAD pixel pitch from the position where the bottom linear array receives the transmitted light.

[0014] Furthermore, the steps S4 and S2 can be replaced.

[0015] In summary, the beneficial technical effects of the present invention are: 1. The present invention includes a plurality of SPAD photodetector chip unit components. A plurality of SPAD chip units are sintered side by side on a ceramic substrate, wherein a certain amount of space is reserved between each SPAD unit and its adjacent SPAD unit, thereby reducing crosstalk between pixels and reducing the blind pixel rate; 2. A beam splitter is sintered at an inclined diagonal position on the U-shaped bracket of the present invention. The inclination angle of the beam splitter forms an angle of 45 degrees with the bottom surface. The positions of the two SPAD linear array units are carefully designed so that their positions are staggered by half the SPAD pixel pitch relative to the light after being incident on the beam splitter and being transmitted and reflected. The whole is easy to assemble, and a larger-scale SPAD array with higher resolution can be prepared. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the installation structure of S1 of the present invention; Figure 3 This is a schematic diagram of the three-dimensional structure of the U-shaped bracket base of the present invention; Figure 4 This is a schematic diagram of the installation structure of S2 of the present invention; Figure 5 This is a schematic diagram of the installation structure of S3 of the present invention; Figure 6 This is a schematic diagram of the S4 installation structure of the present invention. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0018] Reference Figure 1 , a method for manufacturing a single-photon avalanche photodetector linear array, the method is as follows: Reference Figure 2 ,S1: Preparation of linear array unit,First, prepare a ceramic substrate, and sinter multiple groups of SPAD chip units with equal spacing on the ceramic substrate, so that the multiple groups of SPAD chip units with equal spacing form a linear array unit, the ceramic substrate is a substrate with high strength and high thermal conductivity, and the ceramic substrate is one of aluminum oxide (Al2O3), aluminum nitride (AlN) or silicon carbide (SiC), and the ceramic substrate can be a substrate with high strength and high thermal conductivity such as aluminum oxide (Al2O3), aluminum nitride (AlN) or silicon carbide (SiC); Reference Figure 3 and Figure 4, A1: The composition of the SPAD chip unit. The SPAD chip unit includes a single SPAD chip unit, a conductive gold wire and a gold pad. The SPAD chip units are electrically connected through the conductive gold wire and the gold pad. A certain amount of space is reserved between each SPAD unit and its adjacent SPAD unit. The spacing between two SPAD pixels is 100-400μm. A certain amount of space is reserved between each SPAD unit and its adjacent SPAD unit. The spacing distance depends on the size of a single SPAD. Reference Figure 3 and Figure 4 , S2: prepare a base, weld a set of U-shaped bracket bases, and sinter a set of linear array units on the upper end of the bottom surface of the U-shaped bracket base. The U-shaped bracket base can be made of a material with excellent thermal conductivity such as copper; Reference Figure 5 , S3: Beam splitter installation, prepare a group of beam splitters, sinter the beam splitters in the U-shaped bracket base, and install the beam splitters at an angle on the diagonal position of the U-shaped bracket. The beam splitters are mainly used to split the incident light beam into two beams of transmission and reflection with a certain light intensity ratio. Generally, a neutral beam splitter with a transmission and reflection ratio of 50 / 50 is used, but beam splitters with other splitting ratios can also be used in special occasions. The beam splitters are made of glass, metal or other dielectric materials, and have various shapes such as round and square. The beam splitters are sintered at an angle to the U-shaped bracket base. The tilt direction depends on the position of the two SPAD linear array units. Generally, the film layer forms an angle of 45° with the bottom surface; Reference Figure 6 , S4: Complete the installation, sinter another linear array unit to the side of the U-shaped bracket base to complete the installation, the linear array unit is sintered to a side that can receive the light reflected by the beam splitter, the sintering position of the side linear array unit depends on the position of the transmitted light and the reflected light of the beam splitter, and the position where it receives the reflected light after being incident on the beam splitter is staggered by half the distance of the SPAD pixel pitch from the position where the bottom linear array receives the transmitted light, where S2 and S4 can be interchanged depending on the situation.

[0019] Working principle: The SPAD array includes multiple SPAD photodetector chip unit components. Multiple SPAD chip units are sintered side by side on a ceramic substrate. Each SPAD unit is separated from its adjacent SPAD unit by a certain amount of spacing. The spacing distance depends on the size of a single SPAD. Generally, the spacing between two SPAD pixels is guaranteed to be 100-400μm. This is a linear array unit of SPAD. The two linear array units are sintered to the bottom and side of a U-shaped bracket respectively. A beam splitter is sintered at an inclined position on the diagonal of the U-shaped bracket. The inclination angle of the beam splitter is 45 degrees with the bottom surface. The positions of the two SPAD linear array units are carefully designed so that their positions are staggered by half the distance of the SPAD pixel spacing relative to the light that is incident on the beam splitter and then transmitted and reflected.

[0020] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for manufacturing a single-photon avalanche photodetector linear array, characterized in that: The method is as follows: S1: Linear array unit preparation: first prepare a ceramic substrate, and sinter multiple groups of SPAD chip units with equal spacing on the ceramic substrate, so that the multiple groups of SPAD chip units with equal spacing form a linear array unit; A1: The SPAD chip unit consists of a single SPAD chip unit, a conductive gold wire and a gold pad. Each SPAD chip unit is electrically connected through the conductive gold wire and the gold pad. S2: prepare a base, weld a set of U-shaped bracket bases, and sinter a set of linear array units on the upper end of the bottom surface of the U-shaped bracket base; S3: Beam splitter installation: prepare a group of beam splitters, sinter the beam splitters in the base of the U-shaped bracket, and install the beam splitters at an angle at the diagonal position of the U-shaped bracket; S4: Complete the installation and sinter another line array unit to the side of the U-shaped bracket base to complete the installation.

2. The method for manufacturing a single photon avalanche photodetector linear array according to claim 1, characterized in that: The ceramic substrate in S1 is a substrate with high strength and high thermal conductivity, and the ceramic substrate is one of aluminum oxide (Al2O3), aluminum nitride (AlN) or silicon carbide (SiC).

3. The method for manufacturing a single photon avalanche photodetector linear array according to claim 1, characterized in that: A certain amount of space is reserved between each SPAD unit in A1 and its adjacent SPAD unit, and the distance between two SPAD pixels is 100-400 μm.

4. The method for manufacturing a single photon avalanche photodetector linear array according to claim 1, characterized in that: The U-shaped bracket base in S2 is made of a material with excellent thermal conductivity, and the material of the U-shaped bracket base is copper.

5. The method for manufacturing a single photon avalanche photodetector linear array according to claim 1, characterized in that: The beam splitter in S3 is used to split the incident light beam into two beams of transmission and reflection with a certain light intensity ratio, and the beam splitter adopts a neutral beam splitter with a transmission and reflection ratio of 50 / 50.

6. The method for manufacturing a single photon avalanche photodetector linear array according to claim 1, characterized in that: The beam splitter in S3 is made of glass or metal, and the shape of the beam splitter is round or square.

7. The method for manufacturing a single photon avalanche photodetector linear array according to claim 1, characterized in that: The tilt angle of the beam splitter in S3 is specifically that the film layer and the bottom surface form an angle of 45°.

8. The method for manufacturing a single photon avalanche photodetector linear array according to claim 1, characterized in that: The linear array unit in S4 is sintered to a side surface that can receive the light reflected by the beam splitter, and the sintering position of the side linear array unit depends on the position of the transmitted light and the reflected light of the beam splitter. The position where it receives the reflected light after being incident on the beam splitter is staggered by half the SPAD pixel pitch from the position where the bottom linear array receives the transmitted light.

9. The method for manufacturing a single photon avalanche photodetector linear array according to claim 1, characterized in that: The steps S4 and S2 can be replaced.

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