100 nm gate AlGaN/GaN HEMTs on silicon with fT = 90 GHz

The realisation of 0.1 mum gate AlGaN/GaN high electron mobility transistors grown on high-resistivity silicon substrates is reported. A maximum current density of 750 mA/mm and an extrinsic transconductance of 225 mS/mm are achieved. The devices feature a record current gain cutoff frequency as high as f _T=90 GHz, the highest value ever reported from a GaN-based device grown on a silicon substrate. The results demonstrate the great potential of GaN-on-silicon technology for low-cost millimetre-wave applications.