Patent ID: 8044295

Claim:
A structure, comprising: an active semiconductor structure having an active semiconductor front side and an active semiconductor structure back side, wherein the active semiconductor structure produces a voltage between the active semiconductor structure front side and the active semiconductor structure back side when illuminated from the active semiconductor structure front side; a back electrical contact overlying and contacting the active semiconductor structure back side; a front electrical contact overlying and contacting the active semiconductor structure front side, wherein the front electrical contact has multiple layers comprising: a first region overlying and contacting the active semiconductor structure front side, the first region consisting essentially of titanium and gold or palladium; a second region consisting essentially of gold or palladium and overlying and contacting the first region, a barrier layer overlying and contacting the gold or palladium diffusion layer, and a joining layer overlying and contacting the barrier layer; and a front electrical lead overlying and affixed to an attachment pad region of the joining layer of the front electrical contact; wherein the first region is formed by diffusing gold or palladium into a deposited titanium layer.