CMOS (complementary metal-oxide-semiconductor transistor) image sensor pixel and control time sequence thereof

Abstract

The invention discloses a CMOS (complementary metal-oxide-semiconductor transistor) image sensor pixel and a control time sequence thereof. The CMOS image sensor pixel is characterized in that four pixels are arranged to a 2*2 pixel array structure as a group of pixel unit; two pixels of the first column and the second column respectively share selection transistors, source follow transistors, reset transistors and floating active areas; the first column of the pixels and the second column of the pixels form a staggered arrangement structure; and a plurality of groups of the pixel units are arranged to form a two-dimensional pixel array in the vertical direction and the horizontal direction. In the pixel array, a first layer metal connection line is a power control line and a signal output line and is also a column controller timing control line, and a second layer metal connection line is a row encoder timing output control line. With the adoption of the pixel structure array, the light use efficiency of a small area pixel sensor can be improved so as to improve the sensitivity, and the image quality of the small area pixel sensor can be effectively improved.

Description

technical field [0001] The invention relates to a CMOS image sensor, in particular to a CMOS image sensor pixel and its control timing. Background technique [0002] Image sensors are already widely used in digital cameras, mobile phones, medical devices, automobiles and other applications. In particular, the rapid development of CMOS (Complementary Metal Oxide Semiconductor) image sensors has made people have higher requirements for low power consumption, small size, and high resolution image sensors. [0003] The pixel structure arrangement of CMOS image sensors in the prior art takes 4T2S as an example. Because it depends on the structural characteristics of the pixel itself, its array generally requires the first layer of metal, the second layer of metal and the third layer of metal as device interconnections. Multiple rows or columns of first-layer metal, second-layer metal or third-layer metal wiring are required between adjacent rows of pixels or adjacent columns of ...

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Problems solved by technology

[0005] Due to the small photosensitive area and low sensitivity of the small pixel sensor, the information transmitted in dark light is not clear enough

Especially when the first layer of metal, the second layer of metal and the third layer of metal are used as the device interconnection lines, the dielectric height on the surface of the photodiode Si (silicon) is relatively high, and multiple lines between adjacent rows and adjacent columns of pixels The metal connection leads to a low opening ratio of the metal window, which blocks part of the light from entering the photodiode

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