| 摘要 |
PROBLEM TO BE SOLVED: To reduce a laser oscillation surface in fraction defective by a method, wherein a non-oxidized surface is made to serve as the laser oscillation surface of a ridge structure. SOLUTION: After an oxidation treatment is carried out, the entire surface of a mesa A' is coated again with an SiNx film as a protective insulating film. Then, only a protective insulating film and an SiNx thin film 7' formed on the narrow part A2' of the mesa A' are selectively removed to make a contact layer 6 exposed. Then, Ti/Pt/Au are vapor deposited over the entire surface of the mesa A' to form an upper electrode, furthermore the rear of a board 1 is polished, and then AuGeNi alloy is evaporated thereon to serve as a lower electrode. Joined wide parts A1' are cleaved at their center line into bars, and the bar is divided into devices by processing. At this point, a cleavage plane is located at the center line of the wide parts A1', so that a layer 4 is protected against oxidation even during thermal treatment. Therefor, a cleavage plane is a nonoxidized plane and is kept free of distortions due to oxidation and crackings due to cleavage, so that a laser oscillation surface can be reduced in fraction defective. |
