Deep trench isolated anti-crosstalk photoelectric detector and manufacturing method thereof

Abstract

The invention discloses a deep trench isolated anti-crosstalk photoelectric detector, comprising a P-i-N laminar structure formed by sequentially laminating a P-type diffusion layer, a substrate layer and an N-type diffusion layer, wherein an isolation region is formed on the P-i-N laminar structure and divides the photo-surface of the P-i-N laminar structure into a plurality of quadrants. The photoelectric detector is characterized in that the isolation region is realized by adopting the following structure: a deep trench is made in the photo-surface of the P-i-N laminar structure, the cross section contour of the deep trench is matched with the outer contours of the plurality of quadrants, the axial direction of the deep trench is the same as the laminating direction of the P-i-N laminar structure, the depth of the deep trench reaches the upper end surface of the N-type diffusion layer, and the deep trench is filled with an insulating material. The photoelectric detector has the advantages: each quadrant of the quadrant photoelectric detector is effectively isolated, the area of the depletion layer of the photoelectric detector is reduced, the internal junction capacitance area is reduced, the RC time constant is reduced, and the response speed of a device is improved; and the deep trench is positioned in the body of the quadrant photoelectric detector, so that the influence of surface defects on the device is avoided.

Description

technical field [0001] The invention relates to a photodetector manufacturing technology, in particular to a photodetector with deep groove isolation and anti-crosstalk and a manufacturing method thereof. Background technique [0002] In the prior art, an isolation region (also called a blind region) is generally made on a semiconductor silicon detector to form a quadrant photodetector. When the quadrant photodetector is working, photogenerated carriers are generated under the action of light. Under the action of electric field, orderly and directional movement is made to form photocurrent, so that each quadrant outputs signals independently. Due to the disordered movement of some photogenerated carriers in the generation region and the transition region, the photogenerated carriers will enter the surrounding photosensitive regions from their own photosensitive regions, thereby forming photoelectric crosstalk. ), silicon quadrant photodetectors that require a thick depl...

AI Technical Summary

Problems solved by technology

[0003] In order to reduce the impact of photoelectric crosstalk, most of the existing quadrant photodetector chips use PN junctions to isolate each quadrant. PN junctions are used as electrical isolation. For near-infrared wavelengths (1064nm), a high withstand voltage is generally required. Therefore, the depletion region must be Wide, but this will produce bad resistance and capacitance characteristics; another method is to increase the area of ​​the blind zone, which can not only improve the withstand voltage, but also reduce the crosstalk between quadrants, but the increase of the blind zone will lose more light energy. At the same time, There are also strict requirements on the size of the blind area during the use of the device; another method is to thin the photo-generated carrier generation area, although it can also reduce the photoelectric crosstalk, but thinning the thickness of the photo-generated carrier generation area Infrared 1064nm wavelength, the light absorption thickness will be reduced accordingly, which will seriously reduce the responsivity of the photodetector

Images