Abstract A gold-bonding area is exposed by an opening in the upper molybdenum layer of a trimetal molybdenum-gold-molybdenum contact system for a semiconductor device. A layer of chromium, or other suitable corrosion-resistant material, is formed over the edges of the molybdenum layers and extends for a distance over the exposed gold-bonding area in order to seal the edges of the molybdenum layers. An insulation layer is formed over the layer of chromium and selectively removed to define an opening exposing the gold-bonding area. In one embodiment, a second layer of gold is formed over the edges of the chromium layer, with the insulation layer abutting the outer edges of the second gold layer.
The combination of claim 1 wherein said corrosion-resistant material comprises chromium.
Claim 2
Dependent Claim
19 words
The combination of claim 1 wherein said bonding area is of a size to receive a ball bond connection.
Claim 3
Dependent Claim
24 words
The combination of claim 1 and further comprising: a layer of metal covering edge portions of said corrosion-resistant material and abutting said insulation layer.
Claim 4
Dependent Claim
12 words
The combination of claim 4 wherein said layer of metal comprises gold.
Claim 5
Dependent Claim
100 words
A semiconductor device comprising: an insulated semiconductor substrate having a metal contact formed thereon, said metal contact comprising first, second and third adherent metal layers, said first metal layer being adherent to said insulated substrate and said third metal layer having an opening exposing a connection area on said second metal layer, a fourth metal layer over said third metal layer circumventing said connection area and partially covering the exposed area of said second metal layer, said fourth metal layer having corrosion-resistant properties superior to said second metal layer, and a layer of insulation material over said fourth metal layer.
Claim 6
Dependent Claim
31 words
The semiconductor device of claim 6 wherein said first metal layer and said third metal layer are molybdenum, said second metal layer is gold and said fourth metal layer is chromium.
Claim 7
Dependent Claim
22 words
The semiconductor device of claim 6 wherein a portion of said first metal layer electrically contacts a semiconductor region on said substrate.