Patent ID: 7662658

Claim:
A method of forming a photodiode, said method comprising: forming at least one field oxide region of a first conductivity type in a substrate; forming a transistor gate over said substrate and spaced apart from said at least one field oxide region; conducting a first dopant implantation to form a doped region of a second conductivity type in said substrate and laterally displaced from said transistor gate on the opposite side as said at least one field oxide region; forming an in-situ doped layer of said first conductivity type over said transistor gate and over a first area of said substrate, said first area being located between an electrically active area of said transistor gate and said field oxide region; and diffusing ions from said in-situ doped layer into said first area of said substrate to form an ultra-shallow doped layer of said first conductivity type in said substrate, said ultra-shallow doped layer being in contact with said doped region of said second conductivity type.