| 摘要 |
PROBLEM TO BE SOLVED: To constitute the element distribution in the depth direction from the surface as population inversion, by constituting the constituent elements of a first metal layer as elements whose ionization potential is lower than the constituent elements of a second metal layer, constituting the constituent elements of the second metal layer as elements whose ohmic property is more excellent than the constituent elements of the first metal layer, and performing heat treatment after the layers are laminated. SOLUTION: A first metal layer 81 is formed by forming an Ni film of 10-200Å in thickness on a P<+> layer. A second metal layer 82 is formed by forming an Au film of 20-500Å in thicknes on the first metal layer 81. After the Ni film and the Au film are laminated, heat treatment is performed. Au in the second metal layer 82 on the first metal layer of Ni is diffused in the P<+> layer 7 through the first metal layer 81, and forms the state of alloy with GaN of the P<+> layer 7. That is, the distribution of Au and Ni in the depth direction is changed before and after the heat treatment. During the heat treatment, elements in the first metal layer travel the vicinity of the surface. As the reaction, elements of the second metal layer are alloyed with group III nitride semiconductor, and permeate into the semiconductor. Thereby population inversion is realized. |
