In this work, the possibility of achieving GaN-on-Si devices for millimeter wave applications operating at high bias is demonstrated. It is shown that highly scaled AlN/GaN-on-Si double heterostructure enables us to significantly improve electron confinement under high electric field as compared to single heterostructure while delivering high carrier density (>2 × 1013 cm−2). Subsequently, trapping effects can be minimized resulting in the highest GaN-on-Si output power density up to 40 GHz and at a drain bias of 15 V together with a record fmax close to 200 GHz. At higher bias, infrared camera analysis clearly shows that these devices are mainly limited by self-heating effects. Furthermore, low noise figure has been assessed on this heterostructure, promising integration of cost effective low noise and high power millimeter wave amplifiers.
