12 W/mm AlGaN-GaNHFETs on silicon substrates

Al0.26Ga0.74N-GaN heterojunction field-effect transistors were grown by metal-organic chemical vapor deposition on high-resistivity 100-mm Si (111) substrates. Van der Pauw sheet resistance of the two-dimensional electron gas was 300 Omega/square with a standard deviation of 10 Omega/square. Maximum drain current density of similar to1 A/mm was achieved with a three-terminal breakdown voltage of similar to200 V. The cutoff frequency and maximum frequency of oscillation were 18 and 31 GHz, respectively, for 0.7-mum gate-length devices. When biased at 50 N, a 2.14-GHz continuous wave power density of 12 W/mm was achieved with associated large-signal gain of 15.3 dB and a power-added efficiency of 52.7%. This is the highest power density ever reported from a GaN-based device grown on a silicon substrate, and is competitive with the best results obtained from conventional device designs on any substrate.