High performance GaN high electron mobility transistors on low resistivity silicon for X-Band applications

This letter reports the RF performance of a 0.3 m gate length AlGaN/AlN/GaN HEMT realized on a 150 mm diameter low-resistivity (LR) ( < 10 cm) silicon substrate. Short circuit current gain (fT) and maximum frequency of oscillation (fMAX) of 55 GHz and 121 GHz respectively were obtained. To our knowledge, these are the highest fT/fMAX values reported to date for GaN HEMTs on LR silicon substrates.