Test structure for monitoring backside-illumination electronegativity intensity and process integration method

Abstract

The invention discloses a test structure for monitoring backside-illumination electronegativity intensity. The structure comprises a first electrode region with the same process condition as a photosensitive doped region of a pixel region, a first passivation layer including an electronegativity material layer is formed at the back side of the first electrode region, a back side metal layer is formed on the back side of the first passivation layer, the first electrode region, and the first passivation layer and the back side metal layer on the back side are stacked to form a monitoring capacitor. The first electrode region is connected to a first front liner which is connected to a first back liner, a second back liner is formed on the back side of the back side metal layer on the back side of the first electrode region, and lead-out structures of two pole plates of the monitoring capacitor are formed by the first and second back liners. The invention also discloses a process integration method of the test structure for monitoring the backside-illumination electronegativity intensity. The online continuous monitoring of the electronegativity intensity of a backside-illumination image sensor can be achieved, the test period and the feedback period can be effectively shortened, the consumption of a silicon wafer is reduced, and the research and development progress is accelerated.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuit manufacturing, in particular to a test structure for monitoring the electronegativity intensity of the back-illuminated type; the invention also relates to a process integration method for the test structure for monitoring the electronegativity intensity of the back-illuminated type. Background technique [0002] A conventional CMOS image sensor (CMOS Image Sensor, CIS) is composed of a pixel (Pixel) unit circuit and a CMOS circuit. The pixel unit circuit is formed in a pixel area, and the CMOS circuit is formed in a peripheral area. Compared with CCD image sensors, CMOS image sensors have better integration because they adopt CMOS standard manufacturing process, and can be integrated with other digital-analog operations and control circuits on the same chip, which is more adaptable to future development. [0003] The pixel unit circuit in the pixel area includes a photodiode (PD). ...

AI Technical Summary

Problems solved by technology

In the existing technology, since the monitoring of electricity or charge needs to be carried out on the optical chip, and there is a certain change over time, it is impossible to accurately monitor the intensity of the electronegativity, so all the back-end processes can only be done on the silicon chip, including making After the color filter is finished, the quality of the electronegative material can be verified only after the function is tested.

This will make the test cycle of electronegative materials long, and the feedback of process adjustment will have obvious hysteresis. If there is a problem, it will waste a lot of silicon wafers and prolong the development cycle.

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