Test structure and process integrated method for monitoring back-illuminated electronegativity

Abstract

The invention discloses a test structure for monitoring the intensity of back-illuminated electronegativity, which comprises: a first electrode region with the same process conditions as the photosensitive doped region of the pixel region; The first passivation layer of the material layer; a back metal layer is formed on the back side of the first passivation layer, and a monitoring capacitance is formed by overlapping the first electrode area, the first passivation layer and the back metal layer on the back side; the first electrode area is connected to The first front pad, the first front pad is connected to the first back pad; the back side of the back metal layer on the back side of the first electrode area is formed with a second back pad; the first and second back pads form the monitoring capacitance The lead-out structure of the two plates. The invention also discloses a process integration method of the test structure for monitoring the electronegativity intensity of the back-illumination type. The invention can realize the online continuous monitoring of the electronegativity intensity of the back-illuminated image sensor, can effectively shorten the test cycle and the feedback cycle, reduce the consumption of silicon wafers, and accelerate the research and development progress.

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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