Back-illuminated cmos image sensor and manufacturing method thereof

Abstract

The invention provides a backside illuminated CMOS image sensor and a method for manufacturing the backside illuminated CMOS image sensor. The method comprises the steps that a wafer is provided, and a plurality of photodiodes are formed in the wafer; a touch etching stop layer is formed in the front of the wafer; the materials of the touch etching stop layer is SiN, and technological conditions for forming of the touch etching stop layer comprise 2000W-3000W radio-frequency power, a 1000mil-2500mil gap, 4.1Torr-4.3Torr pressure and a 300 DEG C-380 DEG C temperature. Due to the mode, the touch etching stop layer in the backside illuminated CMOS image sensor has high reflectivity, light irradiating on the backside illuminated CMOS image sensor can be well reflected in the photodiodes, and quantum converting efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of image sensors, in particular to a back-illuminated CMOS image sensor and a manufacturing method thereof. Background technique [0002] Image sensors can be divided into charge-coupled device (Charge-Coupled Device) image sensors (commonly known as CCD image sensors) and CMOS (Complementary Metal Oxide Semiconductor) image sensors according to the principle they use. CMOS image sensors are based on complementary metal Manufactured using oxide semiconductor (CMOS) technology. Since the CMOS image sensor is manufactured using a traditional CMOS circuit process, the image sensor and its required peripheral circuits can be integrated. [0003] Traditional CMOS image sensors use Front Side Illumination (FSI) technology to manufacture pixels on the pixel array, and the incident light needs to pass through the front side of the pixel to reach the photo-sensing area. That is to say, the structure of the traditio...

AI Technical Summary

Problems solved by technology

That is to say, the structure of the traditional front-illuminated CMOS image sensor makes the incident light need to pass through the dielectric layer (dielectric layer) and the metal layer (metal layer) before reaching the photo-sensing area, which leads to the traditional CMOS image sensor Need to face low quantum efficiency (quantum efficiency), serious cross talk between pixels (cross talk) and dark current (dark current), etc.

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