A 70-GHZ F(T) LOW OPERATING BIAS SELF-ALIGNED P-TYPE SIGE MODFET

A self-aligned process for the fabrication of SiGe p-type modulation-d oped field-effect transistors (MODFET's) is described, Self-aligned de vices with 0.1-mu m gate-length have been fabricated and characterized , A maximum de extrinsic transconductance of 258 mS/mm was obtained wi th a low turn-on resistance and very low knee voltage, Excellent high frequency performance with a unity current-gain cutoff frequency (f(T) ) of 70 GHz was obtained, This excellent high frequency performance wa s exhibited even at drain bias as low as 0.5 V.