BONDING MATERIAL AND BONDING METHOD FOR ELECTRIC ELEMENT

摘要

A material and method for bonding a semiconductor device to a pedestal, which can obtain satisfactory bonding strength and stable electric contact, are disclosed. On an n- type electrode constituting an ohmic electrode for a semiconductor laser device are formed a N1 layer and an Au-Sn solder layer. Then, the solder layer is melted and bonded to a heat sink provided with Au-plating. The film thickness of the N1 layer is set to approximately 500.ANG. or more. When the solder layer is melted, N1 in the N1 layer diffuses into the solder layer and Sn in the solder layer diffuses into the N1 layer. By this mutual diffusion, bonding strength and wettability between the semiconductor device and pedestal are improved. In addition, by setting the composition ratio of the N1 layer to the Au-Sn solder layer to between about l.3wt% and about lOwt%, the melting point of the mixed alloy is lower, and bonding can be carried out at lower temperatures. Concurrently, a higher bonding strength can be obtained.