A novel In-0.52(Al0.9Ga0.1)(0.48)As/In0.53Ga0.47As HEMT on InP substrate is proposed and fabricated. By adding 10% Ga to the InAlAs layer, the quality of this quaternary InAlGaAs can be improved. This HEMT demonstrated a peak g(m) of 295mS/mm, an f(T) of 35GHz, and an f(max) of 76GHz with a gate length of 0.8 mu m. Furthermore, after 36h of biasing stress, almost no change in drain current and transconductance was observed in the InAlGaAs HEMT, which is a better result than obtainable in conventional InP HEMTs.
