| 摘要 |
PROBLEM TO BE SOLVED: To prevent the thermal damages into a semiconductor layer through heat treatment at a high temperature to a semiconductor, as well as the deterioration of the surface morphology by reducing the temperature of the heat treatment. SOLUTION: A buffer layer 2 consisting of AlN, an Si-doped n-type GaN layer 3, a light- emitting layer 4 having a multiple quantum well structure, in which barrier layers 41 composed of GaN and well layers 42 made up of Ga0.8 In0.2 N are laminated alternately, and a p-type GaN layer 5 are laminated and formed successively on a sapphire substrate 1. A Co metal thin-film is formed onto the layer 5, the resistance of the layer 5 is lowered by heat treatment, and the metal thin-film is removed. A light-transmitting (p)-type electrode 6 consisting of a first metal layer 61 composed of Co and a second metal layer 62 made up of Au and an electrode pad 7 are formed successively onto the p-type layer 5, and an (n) electrode 8, consisting of V and Al or an Al alloy is formed onto the n-type layers 3. The first metal layer 61 formed onto the p-type layer 5 is composed of Co which is easily oxidized, oxidized Co extracts hydrogen from the p-type layer 5 at heat treatment to generate a reducing reaction, reduced Co is oxidized again by conducting heat treatment in an O2 atmosphere, and hydrogen is extracted from the p-type layer 5. In this way, a change into a p-type of the p-type layer 5 is promoted, and the temperature of heat treatment can be lowered. |
