Patent ID: 8502269
Filing Date: 2013-08-06
Classification: H01L

Abstract:
1. A semiconductor device comprising: a first-conductivity-type layer; a first-conductivity-type buried layer whose upper surface is in contact with the first-conductivity-type layer and whose impurity concentration is higher than the impurity concentration of the first-conductivity-type layer; a first first-conductivity-type diffusion layer which is in contact with the first-conductivity-type layer and whose bottom part is in contact with the buried layer; a first second-conductivity-type diffusion layer formed in the first-conductivity-type layer such that a bottom part of the first second-conductivity-type diffusion layer is not in contact with the buried layer; a second second-conductivity-type diffusion layer formed in the first-conductivity-type layer such that a bottom part of the second second-conductivity-type diffusion layer is not in contact with the buried layer and such that a side face of the second second-conductivity-type diffusion layer is at least partially in contact with the first-conductivity-type layer; a second first-conductivity-type diffusion layer formed in the second second-conductivity-type diffusion layer such that the second first-conductivity-type diffusion layer is shallower than the second second-conductivity-type diffusion layer is; a first wiring coupled to a first first-conductivity-type high-concentration diffusion layer formed in a surface region of the first first-conductivity-type diffusion layer and coupled to a first second-conductive-type high-concentration diffusion layer formed in a surface region of the first second-conductivity-type diffusion layer; and a second wiring coupled to the second first-conductivity-type diffusion layer and a second second-conductive-type high-concentration diffusion layer formed in a surface region of the second second-conductivity-type diffusion layer; wherein the first first-conductivity-type high-concentration diffusion layer includes a region in which there is a contact coupled thereto; wherein the region in which there is the contact, the first second-conductivity-type diffusion layer, the second first-conductivity-type diffusion layer, and the second second-conductivity-type diffusion layer wherein in a region in which the second second-conductivity-type diffusion layer and the first-conductivity-type layer are in contact with each other, impurity concentrations of the second second-conductivity-type diffusion layer and the first-conductivity-type layer are higher in a part at a side face of the second second-conductivity-type diffusion layer than in a part at a bottom surface.