Patent ID: 7652344

Claim:
A semiconductor device including a first device region and a second device region, said semiconductor device comprising: a semiconductor substrate; an insulating interlayer formed on said semiconductor substrate; a seal ring composed of a conductive film buried in said insulating interlayer so as to surround an outer periphery of said first device region; a blocking region composed of a well provided on said semiconductor substrate and blocking electric conduction in a path from said first device region to said second device region through said seal ring; a first diffusion layer formed in an upper part of said semiconductor substrate and in contact with said seal ring; and a second diffusion layer formed in contact with said first diffusion layer and covering said first diffusion layer, wherein said second device region is disposed in one of an inside and an outside of said seal ring, and wherein said blocking region is disposed between a seal ring region comprising said seal ring and one of said first device region and said second device region, wherein said blocking region is electrically isolated, wherein said blocking region is disposed between said second diffusion layer and said one of said first device region and said second device region, wherein a conduction type of said second diffusion layer is opposite to a conduction type of said first diffusion layer, and wherein said blocking region is a ring-like region surrounding a whole outer periphery of said one of said first device region and said second device region in a plan view.