Patent ID: 9530838
Filing Date: 2016-12-27
CPC Classification: H01L

Claim Text:
1. A semiconductor device comprising: a semiconductor layer having a first region and a second region surrounding the first region; a plurality of first pillars of a first conductive type and a plurality of second pillars of a second conductive type reversed in conductivity to the first conductive type, the first and second pillars being formed in the semiconductor layer in the first region; a semiconductor element formed above the semiconductor layer in the first region; and a third pillar of the first conductive type and a fourth pillar of the second conductive type, the third and fourth pillars being formed in the semiconductor layer in the second region, wherein the first pillars and the second pillars are arranged alternately, the third pillar is arranged such that it spirally surrounds the first region, the fourth pillar is arranged between the spiral third pillars, the fourth pillar being arranged such that it spirally surrounds the first region, the first pillar is arranged in a first trench formed in the semiconductor layer, the third pillar is arranged in a second trench formed in the semiconductor layer, and a first loop of the spiral third pillar has a corner, and a first side face and a second side face that make up the corner correspond to a (100) plane or a (110) plane.