Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
145 words
The method as recited in claim 1 wherein said gold evaporating step includes the evaporation of gold over the entire exposed top surface of the structure formed by the titanium and platinum layers, said passivation layer and said gold top surface layer, and further including the steps of: after evaporation and prior to gold plating, masking those portions of said evaporated layers which are to be removed from the surface of said passivation layer, said mask preventing the plating of gold on the masked surfaces of said evaporated layer; removing said mask after said plating step; and etching the top surface of the structure formed after said plating step until that portion of the evaporated gold which was masked is removed from said passivation layer, whereby a gold contact is patterned and the top surface of said gold contact is cleaned during said etching step.
Claim 2
Dependent Claim
56 words
The method as recited in claim 2 wherein said platinum and titanium layers are removed from the vicinity of the hole in said passivation layer prior to said evaporation step such that said evaporated gold layer is presented with a double sHallow stepped structure whereby said evaporated layer evenly covers the corners of said shallow steps.
Claim 3
Dependent Claim
144 words
A second metallization system on top of a first metallization system, said first metallization system having a gold top surface, said second metallization system contacting said first metal-lization system through a hole in a passivation layer therebetween, comprising: a layer of titanium on top of said passivation layer and a layer of platinum on top of said titanium layer, both of said layers being removed from the vicinity of said hole; an evaporated layer of gold on top of said platinum layer, on top of all portions of said passivation layer not covered by said titanium and platinum layers and on the gold top surface of said first metallization system; and a layer of plated gold over top of said evaporated layer, said evaporated layer having served as a current carrier in the plating process, whereby said metal layers comprise said second metallization system.
Claim 4
Dependent Claim
180 words
In a multilayered metallization system for contacting elements formed in a semiconductor substrate, a second metallization system on top of a first metallization system, said first metallization system having a gold top surface, said second metallization system separated from said first metallization system by a passivation layer having a hole therethrough, said second metallization system contacting said first metallization system through said hole in the passivation layer therebetween, said second metallization system comprising: a layer of titanium on top of said passivation layer and a layer of platinum on top of said titanium layer, both of said layers being removed from the vicinity of said hole; and a layer of gold on top of said platinum layer, on top of that portion of said passivation layer exposed by the removal of said platinum and titanium layers and on the gold top surface of said first metallization system, whereby said gold layer is presented with a shallow two-step structure such that the corners of said steps are evenly covered with gold, whereby a gold-gold interface exists between said two metallization systems.
Claim 5
Dependent Claim
34 words
The apparatus as recited in claim 5 wherein said first metallization system is a beam lead type metallization system including layers of titanium, platinum and gold, whereby both metallization systems are beam lead structures.
Claim 6
Dependent Claim
26 words
The apparatus as recited in claim 5 wherein said titanium layer is 1100 A in thickness and wherein said platinum layer is 1500 A in thickness.
Claim 7
Dependent Claim
33 words
The apparatus as recited in claim 5 wherein said gold layer is formed by first evaporating a layer of gold and then plating a layer of gold on top of said evaporated layer.
Claim 8
Dependent Claim
16 words
The apparatus as recited in claim 8 wherein said evaporated layer is approximately 5,000 A thick.