Patent attributes
A semiconductor device has a semiconductor substrate, and a parallel p-n layer provided between the main surface and the back surface of the semiconductor substrate, and first-conductivity-type drift region and second-conductivity-type partition regions alternately arranged therein, wherein in the parallel p-n layer, the second-conductivity-type partition regions are periodically formed conforming to a basic periodicity specified by a predetermined distance, and SA/S (where, SA is a sectional area per a single second-conductivity-type partition region as viewed in a plane parallel with the main surface, and S is a sectional area of a unit structural region, periodically formed as containing one of the second-conductivity-type partition regions, as viewed in a plane parallel with the main surface) in an element-forming region allowing current to flow therethrough is smaller than SA/S in at least a portion of a periphery region surrounding the element-forming region.
