Semiconductor device having diffraction grating

摘要

A semiconductor device has a substrate composed of a semiconductor which has one of sphalerite and diamond crystal structures. The substrate has a plane orientation inclined at 0.5 DEG to 15 DEG with respect to one of {111} and {110} planes indicated by Miller indices. A first semiconductor layer is formed on the substrate. The first semiconductor layer has a sawtooth-shaped first periodic structure consisting of one of the {111} and {110} planes indicated by the Miller indices and at least one plane indicated by another index. A second semiconductor layer is formed on the first semiconductor layer. The second semiconductor layer has a second periodic structure having a phase shifted from a phase of the first periodic structure.