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

Abstract

The invention discloses a CMOS image sensor pixel and its control timing. CMOS image sensor pixels include 4 pixels arranged in a 2×2 pixel array structure as a group of pixel units, where the two pixels in the first column and the second column share the selection transistor, source follower transistor, and reset transistor in the column respectively and the floating active area, and the first row of pixels and the second row of pixels form a staggered arrangement structure; multiple groups of pixel units are arranged vertically and horizontally to form a two-dimensional pixel array. In the pixel array, the first layer of metal wiring is the power supply control line and the signal output line is also the timing control line of the column controller, and the second layer of metal wiring is the timing output control line of the row decoder. The pixel structure array of the present invention can improve the light utilization efficiency of the small-area pixel sensor, thereby improving the sensitivity, and can effectively improve the image quality of the small-area pixel image sensor.

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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