Patent ID: 9324782
Filing Date: 2016-04-26
CPC Classification: H01L

Claim Text:
1. A semiconductor device, comprising: a semiconductor substrate of a first conductivity type; a semiconductor layer of the first conductivity type provided on a first main surface of said semiconductor substrate; a well region of a second conductivity type selectively provided in a main surface of said semiconductor layer; and a source region of the first conductivity type selectively provided in a surface of said well region, wherein said semiconductor layer, said well region, and said source region form a unit cell, said unit cell is defined into a certain shape in plan view at said main surface of said semiconductor layer, and a plurality of said unit cells is coupled in a chain manner to form a unit chain structure with a constriction, said certain shape of said unit cell is defined by an outer edge of a virtual region of said semiconductor layer defined so as to include said source region and said well region inside and by respective outer edges of said source region and said well region at a joint with a different unit cell, an active region is composed of a plurality of said unit chain structures, each unit chain structure being arranged in an offset pattern shifted in both horizontal and vertical directions from an adjacent unit chain structure, so as to avoid generation of a gap between said unit cells of adjacent ones of said unit chain structures, and a distance between said well regions defined by adjacent ones of said unit chain structures is uniform in said active region, wherein said certain shape of said unit cell is a hexagonal shape with a pair of opposite corners both having an internal angle of 90 degrees, two opposite sides except four sides forming said pair of opposite corners form said joint, and said unit cells are coupled at said join to connect said source region and said well region in said unit chain structure, in said unit cell, said well region extends along the outer edge of said source region and the respective outer edges of said source region and said well region extend linearly along the four sides forming said pair of opposite corners, in each of areas facing said pair of opposite corners, said source region and said well region form arcuate projections of a central angle of 90 degrees, the projections having the same center of curvature as a first center of curvature while having a first radius of curvature and a second radius of curvature different from each other, and a distance between the respective outer edges of said well region and said source region is set to be a distance corresponding to a difference between said first and second radii of curvature in every area of said unit cell.