Sensitivity Adaptive Image Sensor Pixel Structure

Abstract

The invention discloses an image sensor pixel structure with adaptive sensitivity. The image sensor pixel structure with the adaptive sensitivity comprises a photodiode, a charge transfer transistor, a reset transistor, a source following transistor and a selection transistor, wherein the photodiode, the charge transfer transistor, the reset transistor, the source following transistor and the selection transistor are arranged in a semiconductor base body. The image sensor pixel structure with the adaptive sensitivity further comprises a transistor capacitor and a charge storage region, wherein the transistor capacitor is arranged on one side face of the photodiode. Grid polycrystalline silicon of the transistor capacitor goes deep into the semiconductor silicon base body. A channel of the transistor capacitor is a photodiode region. The charge storage region makes contact with the grid polycrystalline silicon of the transistor capacitor and is connected with the photodiode region. The charge storage region is a source terminal of the charge transfer transistor. By means of the image sensor pixel structure, pixels compress light sensitivity in a high-light environment, the light sensing dynamic range of the pixels is expanded, and the pixels collect more real object information in the high-illumination environment.

Description

technical field [0001] The invention relates to an image sensor, in particular to an image sensor pixel structure with self-adaptive sensitivity. Background technique [0002] Image sensors have been widely used in digital cameras, mobile phones, medical devices, automobiles and other applications. In particular, the rapid development of the technology for manufacturing CMOS (Complementary Metal Oxide Semiconductor) image sensors has made people have higher requirements for the output image quality of the image sensor. [0003] In the prior art, a CMOS image sensor generally adopts a pixel structure with a linear photoelectric response function. Such as figure 1 As shown, it is an active pixel using four transistors of a CMOS image sensor, which is also called a 4T active pixel in the field. The components of a 4T active pixel include: a photodiode 101, a charge transfer transistor 102, a reset transistor 103, a source follower transistor 104, and a selection transistor 1...

AI Technical Summary

Problems solved by technology

In nature, the human eye is sensitive to low light, that is, it has high sensitivity when it perceives low light; it is not sensitive to strong light, that is, it has low sensitivity when it perceives strong light.

It can be seen that the ability of the above-mentioned linear image sensor to collect images is obviously not good.

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