| 摘要 |
PURPOSE:To manufacture the title excellent semiconductor device having few lattice defects by interposing the mixed crystal layer of zinc sulfide and zinc selenide between a gallium arsenide single crystal substrate and a superlattice layer. CONSTITUTION:The title semiconductor device has a gallium arsenide single crystal substrate 1, a superlattice layer 2, in which a plural layer of cadmium sulfide layers 2a and zinc sulfide layers 2b are laminated, and a mixed crystal layer 3 in which the mixed crystal (ZnSxSe1-x) of zinc sulfide and zinc selenide is epitaxial-grown. The mixed crystal ratio (x) of the mixed crystal layer 3 is selected properly, and the lattice constant of the mixed crystal layer 3 is conformed to the in-plane lattice constant of the superlattice layer. There is lattice mismatching between the mixed crystal layer 3 and the gallium arsenide single crystal substrate 1 at that time, but lattice strain by lattice mismatching is relaxed by dislocation when layer thickness is thickened to a certain extent or more, and a lattice constant determined by the mixed crystal ratio is acquired on the interface with the superlattice layer. Accordingly, the semiconductor device does not receive strain from the substrate, and no lattice defect is generated, thus displaying excellent electrical and optical characteristics. |
