BACK-SIDE ILLUMINATED IMAGE SENSOR WITH A JUNCTION INSULATION

摘要

A method for forming a back-side illuminated image sensor, including the steps of: a) forming, from the front surface, doped polysilicon regions, of a conductivity type opposite to that of the substrate, extending in depth orthogonally to the front surface and emerging into the first layer; b) thinning the substrate from its rear surface to reach the polysilicon regions, while keeping a strip of the first layer; c) depositing, on the rear surface of the thinned substrate, a doped amorphous silicon layer, of a conductivity type opposite to that of the substrate; and d) annealing at a temperature capable of transforming the amorphous silicon layer into a crystallized layer.

主权项

1. A back-side illuminated image sensor formed inside and on top of a thinned semiconductor substrate, wherein:
a layer of same conductivity type as the substrate but of higher doping level extends from the rear surface of the substrate; a layer of a conductivity type opposite to that of the substrate extends across a small thickness and over the entire rear surface of the sensor; and doped polysilicon regions, of a conductivity type opposite to that of the substrate, extend orthogonally from the front surface of the substrate to the front surface of said layer (43) of a conductivity type opposite to that of the substrate.