Patent ID: 7459387
Filing Date: 2008-12-02
Classification: H01L

Abstract:
1. A method for making at least one contact pad on a die of a power semiconductor device comprising: forming a lower layer comprising at least one of copper, and alloys thereof adjacent the die, with the copper having a thickness within a range of 0.7 to 10 microns; forming a zinc film overlying the lower layer, with the zinc layer having a thickness within a range of 0.05 to 0.3 microns; and forming an upper layer adjacent zinc film and the lower layer, the upper layer comprising a first film consisting essentially of nickel overlying the zinc film, and a second film consisting essentially of palladium overlying the first film, with the first film having a thickness within a range of 1 to 20 microns and the second film having a thickness within a range of 0.1. to 3 microns so that the power semiconductor device operates at a temperature greater than or equal to 140° C.