Dual-device photosensitive detection unit based on composite dielectric gate, detector and method thereof

A dual-device photosensitive detection unit based on a composite dielectric gate, comprising a composite dielectric gate MOS-C portion having a light sensing function and a composite dielectric gate MOSFET portion having an information reading function, the two portions being formed above a same P-type semiconductor substrate;

• the composite dielectric gate MOS-C portion comprises a charge coupled layer, a first top dielectric layer and a first control gate which are all successively stacked above the P-type semiconductor substrate, wherein an N-type injection layer is formed in the P-type semiconductor substrate and below the charge coupled layer;
• the composite dielectric gate MOSFET portion comprises a bottom dielectric layer, the charge coupled layer, a second top dielectric layer and a second control gate which are all successively stacked above the P-type semiconductor substrate, wherein an N-type source region and an N-type drain region are formed in the P-type semiconductor substrate and on a side close to the bottom dielectric layer, and a threshold adjustment injection region is formed in the P-type semiconductor substrate and below the bottom dielectric layer;
• and
• in the P-type semiconductor substrate, the N-type injection layer is isolated from the N-type source region and the N-type drain region by a shallow trench isolation region and a P+-type injection region.