Patent ID: 7190012

Claim:
A photodiode comprising: a semiconductor substrate; a first conductive type buried layer on the semiconductor substrate; a first conductive type first epitaxial layer on the buried layer; a second conductive type second epitaxial layer on the first epitaxial layer; a first conductive type first junction region in the first epitaxial layer; a first conductive type second junction region in contact with the first junction region extending through the second epitaxial layer; a second conductive type first high density doping layer on the second epitaxial layer; a first conductive type second high density doping layer in the second junction region; an interlayer insulating layer on the second epitaxial layer; an intermetal insulating layer on the interlayer insulating layer; interconnecting structures in the interlayer insulating layer and the intermetal insulating layer in contact with the second high density doping layer; a buffer oxide layer on a portion of the second junction region outside a light-receiving unit; an etching blocking layer on the buffer oxide layer; and an anti-reflective coating (ARC) on the exposed semiconductor surface of the light-receiving unit, the intermetal insulating layer, and the interconnecting structures.