0.10 μm graded InGaAs channel InP HEMT with 305 GHz fT and 340 GHz fmax

We report here 305 GHz f
_T
, 340 GHz f
_max
, and 1550 mS/mm extrinsic g/sub m/ from a 0.10 μm In/sub x/Ga/sub 1-x/As/In/sub 0.62/Al/sub 0.48/As/InP HEMT with x graded from 0.60 to 0.80. This device has the highest f
_T
yet reported for a 0.10 μm gate length and the highest combination of f
_T
and f
_max
reported for any three-terminal device. This performance is achieved by using a graded-channel design which simultaneously increases the effective indium composition of the channel while optimizing channel thickness.