Patent ID: 7470560
Filing Date: 2008-12-30
Classification: H01L

Abstract:
1. A method of forming a photosensor of a pixel cell, said method comprising: forming a first doped layer of a first conductivity type in a substrate, said first doped layer having a first dopant concentration; forming a photosensor comprising a charge collection region of a second conductivity type to a first depth in said first doped layer and between a gate structure and an isolation region; forming an implanted region of said first conductivity type, having a second dopant concentration, within said substrate, wherein said implanted region is located laterally of said photosensor and adjacent said charge collection region, and wherein said implanted region extends vertically within said substrate to a second depth which is greater than said first depth; and forming a floating diffusion region of said second conductivity type in said implanted region for receiving charges gated by said gate structure, wherein said first dopant concentration and said second dopant concentration are unequal.