A composite dielectric grid capacitively coupled variable gain photodetector and its working method

Abstract

The invention discloses a compound dielectric grid capacitive coupling variable gain photosensitive detector and its working method. The detector unit includes a composite dielectric gate MOS capacitor and a composite dielectric gate transistor formed on the same P-type semiconductor substrate, the composite dielectric gate MOS capacitor realizes the photosensitive function of the detector, and the composite dielectric gate transistor realizes the reading function of the detector; Composite dielectric gate MOS capacitors and composite dielectric gate transistors are separated by shallow trench isolation regions in the substrate. Both structures are as follows: a bottom insulating dielectric layer, a floating gate, a top insulating dielectric layer, and a control The gate, the floating gate and the control gate are shared by the composite dielectric gate MOS capacitor and the composite dielectric gate transistor, and more than two control gates are arranged side by side; the composite dielectric gate transistor is also provided with a source and a drain in the substrate. The invention can realize the functions of high dynamic range and variable gain of imaging by selecting different control gates.

Description

technical field [0001] The present invention relates to an imaging detection device, especially the structure and working mechanism of an imaging detection device in the infrared, visible light band to ultraviolet band, and more importantly, through the scheme of multiple control grids, the adjustment of the gain at the device level is realized, and the imaging is realized. High dynamic range. In particular, it relates to a composite dielectric grid capacitive coupling variable gain photosensitive detector with multiple control grids and its working method. Background technique [0002] Imaging detectors have great applications in various fields such as military and civilian use. The main imaging detectors currently developed are CCD and CMOS-APS. CCD appeared earlier, and its technology is relatively mature. Its basic structure is a series of MOS capacitors connected in series. The generation and change of potential wells on the surface of semiconductors are controlled by...

AI Technical Summary

Problems solved by technology

Although the patent CN102938409A proposes a new type of dual-transistor photosensitive detector, which achieves low dark current and high quantum efficiency to a certain extent, it cannot control the gain and is difficult to apply in high dynamic range scenarios, and cannot break through the existing Dynamic range bottleneck of CMOS-APS

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