Global shutter photosensitive detector based on composite dielectric gate PN junction and working method

Abstract

The invention discloses a global shutter photosensitive detector based on a composite dielectric gate PN junction. The unit comprises a composite dielectric gate MOS capacitor, a composite dielectric gate transistor and global shutter structures which are formed above the same P-type semiconductor substrate, wherein the composite dielectric gate transistor comprises a source drain region, a bottom insulating dielectric layer, a floating gate, a top insulating dielectric layer and a control gate; according to the composite dielectric gate MOS capacitor, a bottom insulating dielectric layer, a floating gate, a top insulating dielectric layer and a control gate are sequentially arranged on a substrate; the global shutter structures are arranged on the two sides of the composite dielectric gate MOS capacitor, each global shutter structure comprises a P or P+ type doped isolation region and an N+ type doped region, and photoelectron collection opening and closing during light sensing of the MOS capacitor are achieved by controlling the voltage on the N+ type doped regions. According to the invention, the global exposure function of the detector can be realized without additionally occupying the space of the detector unit, and the influence of dark current noise at the existing shallow trench isolation interface can be avoided.

Description

technical field [0001] The invention relates to the structure and working mechanism of an imaging detection device, especially an imaging detection device in the infrared, visible light band to ultraviolet band, and specifically relates to a photosensitive detector based on a composite dielectric grid PN junction global shutter structure and its working method. Background technique [0002] The current common CMOS-APS is usually composed of a photodiode and three to six transistors, and more complex functions are realized by means of transistor division. CMOS-APS adopts X-Y addressing mode to read signals, so its imaging speed is faster than CCD. At the same time, CMOS-APS is compatible with CMOS technology and is easy to integrate with peripheral circuits. However, because the pixel contains multiple transistors, the fill factor of the pixel is low, which makes the full well charge of CMOS-APS low. In order to ensure high imaging quality, it is difficult to further reduce t...

AI Technical Summary

Problems solved by technology

If it is used to dope a layer of P-type isolation region around it, it will bring problems such as the decrease of full well charge.

In addition, the detector lacks a global shutter structure inside the device. Currently, imaging can only be read by rolling shutter exposure, which severely restricts the imaging of dynamic objects.

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