Microwave performance of 0.4 μm gate metamorphic In 0.29 Al 0.71 As/In 0.3 Ga 0.7 As HEMT on GaAs substrate

MBE grown metamorphic In0.29Al0.71As/In0.3Ga0.7As/GaAs high electron mobility transistors have been successfully fabricated. A 0.4 μm triangular gate device showed transconductance as high as 700 mS/mm at a current density of 230 mA/mm. The measured fT was 45 GHz and fmax was 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%.