Patent ID: 7550785

Claim:
A pseudomorphic high electron mobility transistor structure comprising: a conductive channel layer; a spacer layer situated over said conductive channel layer and in contact with said conductive channel layer; a first etch stop layer situated over said spacer layer and in contact with said spacer layer; a first doped layer situated over said first etch stop layer and in contact with said first etch stop layer; a second etch stop layer situated over said first doped layer and in contact with said first doped layer; a second doped layer situated over said second etch stop layer and in contact with said second etch stop layer; at least one metal layer situated on said spacer layer and formed in an opening in said second doped layer, said opening extending through said second doped layer, said second etch stop layer, said first doped layer, and said first etch stop layer, and terminating above said conductive channel layer; and a metal-semiconductor alloy layer ohmically contacting said at least one metal layer and said conductive channel layer.