Patent ID: 6583454
Filing Date: 2003-06-24
Classification: H01L

Abstract:
A high electron mobility transistor (HEMT) comprising:a semi-insulating silicon carbide substrate; an aluminum nitride buffer layer on said substrate; an insulating gallium nitride layer on said buffer layer; an active structure of aluminum gallium nitride on said insulating gallium nitride layer and including a first undoped aluminum gallium nitride layer on said insulating gallium nitride layer, a conductively doped aluminum gallium nitride layer on said first undoped aluminum gallium nitride layer, and a second undoped aluminum gallium nitride layer on said conductively doped aluminum gallium nitride layer; a passivation layer on said second undoped aluminum gallium nitride layer; respective source, drain and gate electrodes in contact with said second undoped aluminum gallium nitride layer; said gate electrode having a gate width of 1.5 mm and a gate length of 0.45 &mgr;m, with a gate to source length of 1 &mgr;m and a gate to drain length of 1.5 &mgr;m; and said HEMT being characterized by a power added efficiency of about 28.3 percent at an operating frequency of 10 GHz and a drain bias of about 32 volts.