SiGe pMODFETs on silicon-on-sapphire substrates with 116 GHz f(max)

The de and microwave results of Si0.2Ce0.8/Si0.7Ge0.3 pMODFETs grown on sil icon-on-sapphire (SOS) substrates by ultrahigh vacuum chemical vapor deposi tion are reported, Devices with L-g = 0.1 mum displayed high transconductan ce (377 mS/mm), low output conductance (25 mS/mm), and high gate-to-drain b reakdown voltage (4 V), The de: current-voltage (T-V) characteristics were also nearly identical to those of control devices grown on bulk Si substrat es, Microwave characterization of 0.1 x 50 mum(2) devices yielded unity cur rent gain (f(T)) and unilateral power gain (f(max)) cutoff frequencies as h igh as 50 GHz and 116 GHz., respectively. Noise parameter characterization of 0.1 x 90 mum(2) devices revealed minimum noise figure (F-min) of 0.6 dB at 3 GHz and 2.5 dB at 20GHz.