Method for forming a back-side illuminated image sensor with a junction insulation
First Claim
1. A method for forming a back-side illuminated image sensor from a semiconductor substrate comprising, stacked on each other, a first layer of a first doping level on the rear surface side, and a second layer of same conductivity type as the first layer but of lower doping level on the front surface side, this method comprising:
- a) forming, from the front surface, doped polysilicon regions, of a conductivity type opposite to that of the substrate, extending in depth orthogonally to said 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 said amorphous silicon layer into a crystallized layer.
2 Assignments
0 Petitions
Accused Products
Abstract
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.
-
Citations
5 Claims
-
1. A method for forming a back-side illuminated image sensor from a semiconductor substrate comprising, stacked on each other, a first layer of a first doping level on the rear surface side, and a second layer of same conductivity type as the first layer but of lower doping level on the front surface side, this method comprising:
-
a) forming, from the front surface, doped polysilicon regions, of a conductivity type opposite to that of the substrate, extending in depth orthogonally to said 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 said amorphous silicon layer into a crystallized layer. - View Dependent Claims (2, 3, 4, 5)
-
Specification