0.1 mu m gate length p-type Ge/Si0.4Ge0.6 MODFET with 135GHz f(max)

The authors report on RF results of p-type Ge channel modulation doped fiel d effect transistors (MODFETs) with a gate length of 0.1 mu m. The structur e was grown on a relaxed 4.9 mu m thick compositionally graded Si0.4Ge0.6 b uffer. The devices exhibit DC transconductances up to 190mS/mm and saturati on currents up to 190mA/mm. Cutoff frequencies of f(T) 59GHz and f(max) = 1 35GHz have been obtained. The f(max) value is, to the knowledge of the auth ors, the highest reported so far for p-type Si-based devices.