Backside deep trench-isolated backside-illuminated image sensor manufacturing method

Abstract

The present invention provides a backside deep trench-isolated backside-illuminated image sensor manufacturing method. The manufacturing method comprises the steps of providing a first wafer; forming a dielectric layer on the first surface of the first wafer and etching the dielectric layer to expose the first surface of the first wafer to form a plurality of isolation regions; selectively extending the first wafer to cover the isolation regions; forming an image sensor device, thinning or removing one part of the second surface of the first wafer to form a deep trench isolation structure. According to the technical scheme of the invention, the deep trench isolation region of the dielectric layer is formed before the formation of the image sensor device. The isolation regions are good in surface shape and have fewer defects. Meanwhile, through selectively extending the first wafer to cover the isolation regions, the isolation regions are protected. Since the silicon grows after the formation of the isolation regions, no stress is conducted into the region of the silicon device during the high-temperature process.

Description

technical field [0001] The invention relates to the field of image sensors, in particular to a back-illuminated image sensor adopting back-illuminated deep trench isolation. Background technique [0002] An image sensor is a semiconductor device that converts an optical signal into an electrical signal, and the image sensor has a photoelectric conversion element. [0003] Image sensors can be further divided into complementary metal oxide (CMOS) image sensors and charge-coupled device (CCD) image sensors. The advantage of the CCD image sensor is that it has high image sensitivity and low noise, but it is difficult to integrate the CCD image sensor with other devices, and the power consumption of the CCD image sensor is relatively high. In contrast, CMOS image sensors have the advantages of simple process, easy integration with other devices, small size, light weight, low power consumption, and low cost. Therefore, with the development of technology, CMOS image sensors are ...

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Problems solved by technology

[0005] The problem to be solved by the present invention is a method of manufacturing a back-illuminated image sensor using deep trench isolation on the back, so as to solve the problem that the defects of deep trench isolation are difficult to remove. Celsius, it will cause functional damage to the image sensor device and affect the quality of the image sensor device

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