Patent ID: 8097501

Claim:
A method for manufacturing a semiconductor device, comprising: forming a first-conductivity-type semiconductor region on a semiconductor layer; forming a mask member on the first-conductivity-type semiconductor region; selectively forming an opening in the mask member; etching the first-conductivity-type semiconductor region exposed to the opening to form a trench having a larger diameter than the opening and an eaves-like mask projected above the trench and made of the mask member; forming a second-conductivity-type semiconductor region in the trench below the eaves-like mask by epitaxial growth to form a structure section in which the first-conductivity-type semiconductor region and the second-conductivity-type semiconductor region are alternately repeated in a direction generally parallel to a major surface of the semiconductor layer; and removing a surface portion of the structure section to a depth L satisfying L < (W1/2)× tan ⊖, where W 1 is a diameter of the opening having a smaller diameter than the trench, and ⊖ is an angle between the major surface of the semiconductor layer and a first growth surface of the second-conductivity-type semiconductor region which is non-parallel to a sidewall of the trench.