| 摘要 |
PROBLEM TO BE SOLVED: To improve the crystallinity of continued epitaxial thin film by growing a low-temperature buffer layer formed of group III nitride semiconductor on a crystal substrate and making an area adjacent to the boundary between the low-temperature buffer layer and crystal substrate to be of single crystal when the epitaxial layer formed of group III nitride semiconductor is grown at a high temperature. SOLUTION: A cleaned sapphire substrate 101 is placed in a MOCVD growth furnace, and after the furnace is made vacuum, a highly pure hydrogen gas is allowed to flow therein and the substrate 101 is subject to thermal cleaning by raising temperature to 1100 deg.C. Then the temperature thereof is lowered to 420 deg.C, and a material gas is supplied successively to grow a low-temperature buffer layer 102 made of GaN through the normal pressure MOCVD method, thereby forming an area of about 10nm in thickness of single crystal 103 from the boundary of the layer 102. The upper area thereon is formed mainly of amorphous substance 104 of GaN. Then the temperature of the substrate is raised, and an epitaxial layer is successively piled up on the layer 102 so as to form an epitaxial wafer for light emitting element. |
