| 摘要 |
PURPOSE:To improve a lead frame in bonding strength without the risk of a short circuit between elements by a method wherein the outermost layer of an ohmic electrode formed on the rear of a compound semiconductor substrate is formed of an AuGe layer or an AuSn layer. CONSTITUTION:An N-type GaAs epitaxial layer 12 and a P-type GaAs epitaxial layer 13 are successively formed on an N-type GaAs substrate 11 which contains Si impurity. Then, AuZn alloy is evaporated into a pattern for the formation of a P-side electrode 14. An ohmic electrode 19 composed of an AuGe layer 15, an Ni layer 16, an Au layer 17, and an AuGe layer 18 is formed on the rear side of the substrate 11. The amount island of a lead frame 23, whose main component is Fe, coated with an Ag plating layer 22 is heated at a temperature of 400 deg.C by a heater, an infrared lead chip 10 is placed thereon and die- bonded as being weighted. At this time, the layer 18 is fused, and Au and Ag diffuse into the layer 18 from the layers 17 and 22 respectively to form a ternary alloy 21 of Au-Ge-Ag. |
