Enhancement-Mode Metamorphic HEMT on GaAs Substrate With 2 S/mm $g_{m}$ and 490 GHz $f_{T}$

This letter presents the results of an enhancement mode metamorphic high-electron-mobility transistor device on a GaAs substrate with a 70% indium composition channel. A 35-nm gate length device exhibits a 490-GHz current gain cutoff frequency (f
_T
), a transconductance (g
_m
) of 2 S/mm, a threshold voltage (V
_th
) of 0.11 V (enhancement mode) and a low on- resistance of 0.37 Omega mm. These attributes make the device well- suited for millimeter-wave circuit applications.