Photosensitive detector based on transverse depletion of composite dielectric gate and method thereof

Abstract

The invention discloses a photosensitive detector based on the transverse depletion of a composite dielectric gate and a method thereof. A unit of the detector comprises a composite dielectric gate MOS capacitor and a composite dielectric gate transistor which are formed above the same P-type semiconductor substrate, wherein the composite dielectric gate transistor comprises a source-drain region,a first bottom insulating dielectric layer, a first floating gate, a first top insulating dielectric layer and a first control gate; the composite dielectric gate MOS capacitor is sequentially provided with a second bottom insulating dielectric layer, a second floating gate, a second top insulating dielectric layer and a second control gate on the substrate, and the first floating gate is connected with the second floating gate; an N or N-type photosensitive region is arranged in a substrate of the composite dielectric gate MOS capacitor; and a P or P+ type isolation region is arranged aroundthe photosensitive region and is used for separating the composite dielectric gate transistor from the composite dielectric gate MOS capacitor. The quantum efficiency of the detector can be improved,the wavelength range of light response is expanded, and the noise caused by recombination generated by the surface energy level is reduced.

Description

technical field [0001] The 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 in particular to a photosensitive detector based on composite dielectric grid lateral depletion and a method thereof. Background technique [0002] CCD and CMOS-APS are the two most common imaging devices at present. The basic structure of the CCD that appeared earlier is a group of MOS capacitors connected in series. The generation and change of the potential well on the semiconductor surface is controlled by the pulse timing on the MOS capacitor, so as to realize the storage and transfer of photogenerated charges. This kind of method causes the imaging speed of CCD to be slower, and CCD is extremely high to the requirement of technology simultaneously, makes its yield rate low, and cost is bigger. CMOS-APS usually consists of a photosensitive diode and three t...

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Problems solved by technology

However, in order to obtain a larger and deeper depletion region to obtain a higher and wider-band photoresponse, the dual-transistor photosensitive detector needs to apply a large positive bias voltage on the gate substrate, which is not conducive to the realization of the system, its safety and Reliability is also difficult to guarantee

Especially after the isolation implant is added to the P-type photosensitive area, since the isolation is P+-type ion implantation, the isolation will be exhausted during the working process, resulting in the inability to generate a depletion region with sufficient depth, and the range of response wavelengths is severely restricted.

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