Patent ID: 9257551
Filing Date: 2016-02-09
CPC Classification: H01L

Claim Text:
1. A semiconductor device comprising: a semiconductor substrate of a first conductivity type having a main surface; a first impurity region of the first conductivity type formed over a prescribed depth from said main surface of said semiconductor substrate, and having a first impurity concentration; a second impurity region of a second conductivity type formed over a prescribed depth from a surface of said first impurity region to be surrounded by said first impurity region on side and lower portions, and having a second impurity concentration; a third impurity region of the second conductivity type formed over a prescribed depth from a surface of said second impurity region to be surrounded by said second impurity region on side and lower portions, and having a third impurity concentration higher than said second impurity concentration; a fourth impurity region of the first conductivity type formed over a prescribed depth from the surface of said first impurity region to be surrounded by said first impurity region on side and lower portions, and having a fourth impurity concentration higher than said first impurity concentration; an isolation region formed between said third impurity region and said fourth impurity region to electrically isolate said third impurity region and said fourth impurity region from each other; a fifth impurity region of the second conductivity type formed over a prescribed depth from said main surface of said semiconductor substrate at a distance from said first impurity region, and having a fifth impurity concentration; a seventh impurity region of the second conductivity type formed over a prescribed depth from a surface of the fifth impurity region and surrounded by the fifth impurity region on side and lower portions, and having a seventh impurity concentration higher than the fifth impurity concentration; and an electrode portion formed on a region lying between said second impurity region and said fifth impurity region.