| 摘要 |
PURPOSE:To prevent chip exfoliation by reducing the thermal resistance by improving the adhesive to packages and the like by a method wherein the back of a compound semiconductor chip is coated with a metallic layer having Au and Si. CONSTITUTION:The back of a wafer finished in the formation of surface elements of a GaAs MESFET is polished, and Ti2, Pt3, and Au4 are successively adhered. Further, Au and Si are adhered in 21 layers alternately, and the ratio of film thickness is chosen so that the weight ratio of Au which forms a multilayer film 7 may becomes a ratio of 5.8-6.4wt%. This wafer is diced into a FET chip 1, which is placed on a pre-heated ceramic package 6 and adhered thereto. It is equivalent to the uniform deposition of solder to the chip back, and the problem of wetting of the chip with the solder is eliminated. |
