Microwave performance of 0.4 mu m gate metamorphic In0.29Al0.71As/In0.3Ga0.7As HEMT on GaAs substrate

MBE grown metamorphic In_0.29Al_0.71As/In_0.3Ga_0.7As/GaAs high electron mobility transistors (HEMTs) have been successfully fabricated. A 0.4 mu m triangular gate device showed transconductance as high as 700 mS/mm at a current density of 230 mA/mm. The measured f_T was 45 GHz and f_max was 115 GHz. These high values are, to the authors knowledge, the first reported for submicrometre metamorphic InAlAs/InGaAs/GaAs HEMTs with an indium content of 30%.