Maximum frequency of oscillation of 1.3 THz obtained by using an extended drain-side recess structure in 75-nm-gate InAlAs/InGaAs high-electron-mobility transistors

A maximum frequency of oscillation (f(max)) of 1.3 THz was achieved using an extended drain-side recess structure of InAlAs/InGaAs high-electronmobility transistors (HEMTs), although the gate length was relatively long at 75 nm. The high f(max) was improved by reducing the drain output conductance (g(d)). The use of an asymmetric gate recess structure and double-side doping above and below a channel region were effective in reducing g(d). Further improvements in transconductance (g(m)) and g(d) were achieved by reducing the distance between the source and gate electrodes. (C) 2017 The Japan Society of Applied Physics