3D global image element structure and preparation method thereof

Abstract

The invention discloses a 3D global image element structure and a preparation method thereof. The structure comprises an optical signal generation circuit unit manufactured on a first silicon substrate layer, and a signal storage capacitor unit manufactured on a second silicon substrate layer. The optical signal generation circuit unit and the signal storage capacitor unit are arranged in the vertical direction and are mutually connected through the connection of through holes, metal connection lines and contact holes. According to the technical scheme of the invention, based on the back lighting technology and a 3D stacking structure, three-dimensional unit structures are manufactured on different layers. Meanwhile, based on the vertical connection of the optical signal generation circuit unit and the signal storage capacitor unit, not only a light path between the outside and a photosensitive diode is improved, but also the light isolation degree of the signal storage capacitor is improved. Moreover, the chip area occupied by pixel units is reduced.

Description

technical field [0001] The invention relates to the technical field of semiconductor image sensing, and more particularly, to a high fill factor global shutter pixel unit with a 3D structure and a preparation method thereof. Background technique [0002] Traditional global shutter pixel technology is mainly used in CCD image sensors. Due to the increasing popularity of CMOS image sensors, and because machine vision, film production, industrial, automotive, and scanning applications must capture fast-moving objects with high Traditional barriers associated with shutter pixel technology. With this effort, the provided global shutter pixel technology has smaller pixel size, larger fill factor, lower dark current, and lower noise, making CMOS image sensors the preferred choice for CCD sensors in more applications. Viable alternatives. [0003] In the traditional global pixel, the photosensitive diode and the signal storage and readout circuit unit devices are all manufactured...

AI Technical Summary

Problems solved by technology

Although this structure realizes the separation of the photodiode and other circuits of the pixel to reduce the pixel area, the photodiode, capacitor and readout circuit of the pixel need to be divided into three parts, which is difficult to manufacture and the structure is too complicated

And the path between the capacitor and the photodiode and the readout circuit is easier to introduce more parasitic resistance and capacitance, thereby increasing the readout noise of the pixel

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