Patent ID: 7374961
Filing Date: 2008-05-20
Classification: H01L

Abstract:
1. A method of manufacturing an image pickup device having at least one insulated gate field effect transistor in an output circuit of the image pickup device and that is formed in a substrate, said method comprising the steps of: forming, prior to forming said insulated gate field effect transistor, a first diffusion layer of a first conduction type in said substrate beneath where said insulated gate field effect transistor is to be formed, at a position deeper than a region where a source region and a drain region of said insulated gate field effect transistor are to be formed, the first diffusion layer underlying an entire area of said source region and an entire area of said drain region and entirely separated from said source region and said drain region; and forming, prior to forming said insulated gate field effect transistor and after forming the first diffusion layer, a second diffusion layer of the first conduction type having a higher concentration than said first diffusion layer in said substrate at a position deeper than said first diffusion layer, the second diffusion layer being entirely separated from said first diffusion layer by an intervening layer having a conduction type that is different than the first conduction type.