Semiconductor device having diffraction grating

A semiconductor device comprising:

• a semiconductor having one of sphalerite and diamond crystal structures, said semiconductor constituting a substrate;
• a grating formed on a portion of the semiconductor constituting the substrate which is inclined at 0.5.degree. to 15.degree. with respect to a first plane indicated by Miller indices, a surface of said grating having continuously changing Miller indices;
• a first semiconductor layer which is formed on said grating, said first semiconductor layer doped with an amphoteric impurity, said first semiconductor layer having a sawtooth-shaped first periodic structure comprising a terrace portion comprising said first plane and a step portion comprising a second plane indicated by other Miller indices;
• and
• a second semiconductor layer which is formed on said first semiconductor layer, and has a second periodic structure having a phase shifted from a phase of said first periodic structure, wherein said first semiconductor layer has a first region ranging from said second plane or a plane in the vicinity of said second plane indicated by Miller indices in said grating surface to said step portion and which has one of n-type and p-type conductive regions, and said first semiconductor layer has a second region of the other of said n-type and p-type conductive regions.