CMOS image sensor structure and manufacturing method

Abstract

The invention discloses a CMOS image sensor structure, which comprises a pixel unit array region located on a silicon substrate and a peripheral circuit region located around the pixel unit array region; a buried oxide layer is arranged in the silicon substrate; the buried oxide layer is divided into a first buried oxide layer located in the pixel unit array region and a second buried oxide layerlocated in the peripheral circuit region; a photosensitive part and a suspended drain electrode of the pixel unit are arranged on the front surface of the silicon substrate in the pixel unit array region; a peripheral circuit is arranged on the front surface of the silicon substrate in the peripheral circuit region; the photosensitive part penetrates through the first buried oxide layer, and the suspended drain electrode is arranged on one side, facing the front surface of the silicon substrate, of the first buried oxide layer; and the peripheral circuit is arranged on one side, facing the front surface of the silicon substrate, of the second buried oxide layer. Parasitic capacitance can be reduced, the quantum efficiency of the pixel unit is improved, and optical crosstalk is prevented. The invention further discloses a manufacturing method of the CMOS image sensor structure.

Description

technical field [0001] The invention relates to the technical field of semiconductor processing, in particular to a CMOS image sensor structure and a manufacturing method. Background technique [0002] An image sensor refers to a device that converts optical signals into electrical signals. Large-scale commercial image sensor chips include charge-coupled device (CCD) and complementary metal-oxide semiconductor (CMOS) image sensor chips. Compared with traditional CCD sensors, CMOS image sensors have the characteristics of low power consumption, low cost and compatibility with CMOS technology, so they are more and more widely used. Now, CMOS image sensors are not only used in consumer electronics fields such as miniature digital cameras (DSCs), mobile phone cameras, video cameras, and digital single-lens reflex cameras (DSLRs), but also in automotive electronics, monitoring, biotechnology, and medicine. In order to realize effective photoelectric conversion, the thickness of ...

AI Technical Summary

Problems solved by technology

Since the thickness of the device silicon substrate of conventional SOI silicon wafers is much smaller than that required by conventional back-illuminated CMOS image sensors, it is difficult to fabricate the pixel unit structure of CMOS image sensors in SOI silicon wafers by conventional techniques

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