| 摘要 |
A semiconductor device is provided with: a substrate having a main surface inclined in an off direction from a {0001} face; a semiconductor layer; and an epitaxial layer. The semiconductor layer contains a trench. If the off direction is projected onto the main surface of the substrate, and if we let the upstream side of the resulting direction be an off-angle upstream side, and the downstream side be an off-angle downstream side, then side walls of the trench include first and second side wall portions which face one another and each intersect the off direction of the substrate, and the first side wall portion is located further toward the off-angle upstream side than the second side wall portion. The epitaxial layer is disposed at least on the first and second side wall portions of the trench, and on a first part of the main surface of a source region, located on the off-angle upstream side of the trench, and on a second part of the main surface of the source region, located on the off-angle downstream side of the trench. If the maximum thickness of the epitaxial layer on the first part is TL, the minimum thickness on the second part is TR (where TR>0), and the thickness of the source region is TS, the relationship TS>|TL-TR| is satisfied. |
