US 6,639,293 B2 · Solid-state imaging device

Abstract

A solid-state imaging device such as a CMOS image sensor includes photodiode portions that are designed for both improving sensitivity and reducing crosstalk of electrical charge to adjacent pixels. A p-type layer, which has an impurity concentration that is lower than that of a substrate p+-layer, is formed on the substrate p+-layer which is a p-type silicon semiconductor substrate of high impurity concentration. An n-type photoelectric conversion region is provided at a position on the upper side of the p-type layer. By means of this configuration, of the photoelectrons that are generated in the p-type layer, electrons that diffuse in the direction of the substrate are reliably captured in substrate p+-layer and annihilated by recombination.

Claims11

Dependent claims

A solid-state imaging device, comprising:

a substrate layer which is composed of a semiconductor of a first conductive type;
a semiconductor layer of said first conductive type which is provided on said substrate layer;
a photoelectric conversion region of a second conductive type, which is an opposite conductive type of said first conductive type, provided on said semiconductor layer;
and
a surface layer of said first conductive type which is provided on said photoelectric conversion region;
wherein impurity concentrations of said substrate layer and said surface layer are higher than an impurity concentration of said semiconductor layer, and
wherein a depth profile of impurity in said semiconductor layer is a retrograde profile that decreases away from a PN junction.

4 more elements

Dependencies are inferred from the claim text.

Solid-state imaging device

Life of this patent

Solid-state imaging device

Life of this patent

Abstract

Claims11