Patent ID: 7592205
Filing Date: 2009-09-22
Classification: H01L

Abstract:
1. A method for forming a semiconductor wafer, comprising: providing a silicon substrate, a first circuit layer over said silicon substrate, a second circuit layer over said silicon substrate and over said first circuit layer, a dielectric layer between said first and second circuit layers, an aluminum pad over said silicon substrate, and a passivation layer over said silicon substrate, over said first and second circuit layers and over said dielectric layer, wherein said passivation layer comprises an insulating nitride layer, and wherein an opening in said passivation layer is over said aluminum pad, and said aluminum pad is at a bottom of said opening in said passivation layer; forming a metal layer on said aluminum pad and over said passivation layer; after said forming said metal layer, forming a photoresist layer on said metal layer, wherein an opening in said photoresist layer is over said metal layer; after said forming said photoresist layer, electroplating a gold layer on said metal layer under said opening in said photoresist layer; after said electroplating said gold layer, removing said photoresist layer; after said removing said photoresist layer, removing said metal layer not under said gold layer; after said removing said metal layer, forming a first polyimide layer over said gold layer; and after said forming said first polyimide layer, curing said first polyimide layer with a temperature profile having a peak temperature between 200 and 320 degrees Celsius.