35-nm zigzag T-gate In0.52Al0.48As/In0.53Ga0.47As metamorphic GaAsHEMTs with an ultrahigh fmax of 520 GHz

Metamorphic GaAs high electron mobility transistors (mHEMTs) with the highest-f(max) reported to date are presented here. The 35-nm zigzag T-gate In0.52Al0.48As/ In0.53Ga0.47As metamorphic GaAs HEMTs show f(max) of 520 GHz, f(T) of 440 GHz, and maximum transconductance (g(m)) of 1100 mS/mrn at a drain current of 333 mA/mm. The combinations of f(max) and f(T) are the highest data yet reported for mHEMTs. These devices are promising candidates for aggressively scaled sub-35-nm T-gate mHEMTs.