D. Xu et al., An 0.03-mu m gate-length enhancement-mode InAlAs/InGaAs/InP MODFET's with 300 GHz f(T) and 2 S/mm extrinsic transconductance, IEEE ELEC D, 20(5), 1999, pp. 206-208
We have developed high-performance enhancement-mode InP-based modulation-do
ped field-effect transistors with 0.03-mu m gate-length. A record high curr
ent gain cutoff frequency exceeding 300 GHz has been achieved, and the maxi
mum extrinsic transconductance is as high as 2 S/mm with an associated drai
n current of 0.5 A/mm at a drain bias of 1 V, This high performance is a re
sult of the reduction of gate length, the use of the high barrier metal Pt
as gate electrodes, and most importantly, the employment of the well-develo
ped wet etching technology that allows the formation of a very deep gate gr
oove while retaining small side etching. The excellent E-MODFET performance
opens up the possibility of implementing ever faster high-speed circuits b
ased on direct-coupled FET logic.