Implementation method of CMOS image sensor

Abstract

The invention provides a CMOS (Complementary Metal Oxide Semiconductor) image sensor implementation method. The method comprises the following steps of forming a trench on a semiconductor substrate, and forming a source following transistor of an image sensor pixel unit in the subsequent step by at least part of the trench; filling a third barrier layer to cover the trench; etching a partial region around the trench by adopting a graphical process to form a shallow trench isolation structure; filling an oxide layer to cover the shallow trench isolation structure; chemically and mechanically grinding the oxide layer until reaching the third barrier layer; removing the third barrier layer; and filling the trench with a polycrystalline silicon layer, and etching at least part of the trench toform a source following transistor.

Description

technical field [0001] The invention relates to a method for realizing a CMOS image sensor. Background technique [0002] Image sensors have become ubiquitous. Image sensors are widely used in digital still cameras, cellular phones, surveillance cameras, as well as in medical, automotive and other applications. The technology used to manufacture image sensors continues to advance substantially. For example, demands for higher resolution and lower power consumption have driven further miniaturization and integration of these devices. At present, image sensors can be classified into charge coupled device (CCD, Charge Coupled Device) image sensors and metal oxide semiconductor (CMOS, Complementary Metal-Oxide Semiconductor) image sensors. Among them, due to the high integration, good compatibility, and low power of the CMOS image sensor, and with the improvement of the CMOS manufacturing process, the CMOS image sensor has become the mainstream technology of the current image...

AI Technical Summary

Problems solved by technology

[0004] With the shrinking of the feature size of CMOS image sensors, on the one hand, in order to reduce the readout noise of image sensors, high-performance source-follower transistors are required; The N-type dopant dose and doping depth of the diode; while the gate structure of the TX tube in the prior art is a planar structure, the photogenerated electrons in the N-type depth of the photodiode may not be read out, eventually resulting in Lag (image sticking) ) appears

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