Patent ID: 8125041

Claim:
A semiconductor device, comprising: a semiconductor substrate through which a through hole extending from the top surface through the bottom surface is formed; a through electrode filled in the through hole to extend through the semiconductor substrate; an insulating film formed on the inner wall of the through hole to surround the side surface of the through electrode; a first diffusion layer containing impurities formed in a region of an upper portion of the semiconductor substrate located on a side of the through electrode; a second diffusion layer formed to cover the first diffusion layer, the second diffusion layer containing impurities at a lower concentration and hence being higher in electric resistance than the first diffusion layer; and a connection electrode formed on the top surface of the semiconductor substrate to be connected to the through electrode, wherein a portion of the side surface of the through electrode facing the second diffusion layer is curved toward the inside of the through hole, an imaging region in which a plurality of light-receiving portions are arranged is formed on the top surface of the semiconductor substrate, a peripheral circuit is formed on the top surface of the semiconductor substrate in a region outside of the imaging region, and the first diffusion layer and the second diffusion layer constitute part of the peripheral circuit.