Semiconductor device and manufacturing method thereof

Abstract

A manufacturing yield and reliability of a semiconductor device including a power semiconductor element is improved. A plurality of trenches DT extending in an x direction and spaced apart from each other in a y direction orthogonal to the x direction are formed in a substrate having a main crystal surface tilted with respect to a <11-20> direction. Also, a super-junction structure is constituted of a p-type column region PC made of a semiconductor layer embedded in the trench DT and an n-type column region NC made of a part of the substrate between the trenches DT adjacent in the y direction, and an angle error between the extending direction of the trench DT (x direction) and the <11-20> direction is within ±θ. The θ is determined by {arctan {k× (w/h)}}/13 for the trench having a height of h and a width of w. Herein, the k is at least smaller than 2, preferably 0.9 or less, more preferably 0.5 or less, and still more preferably 0.3 or less.