MICROWAVE PERFORMANCE OF 0.4-MU-M GATE METAMORPHIC IN0.29AL0.71AS IN0.3GA0.7AS HEMT ON GAAS SUBSTRATE

MBE grown metamorphic In0.29Al0.71As/In0.3Ga0.7As/GaAs high electron m obility transistors have been successfully fabricated. A 0.4 mum trian gular gate device showed transconductance as high as 700 mS/mm at a cu rrent density of 230 mA/mm. The measured f(T) was 45 GHz and f(max) wa s 115 GHz. These high values are, to the author's knowledge, the first reported for submicrometre metamorphic InAlAs/InGaAs/GaAs HEMTs with an indium content of 30%.