Ultrathin barrier GaN-on-Silicon devices for millimeter wave applications

•A novel GaN-on-Si double heterostructure based on AlN/GaN showing breakthrough performances has been developed.•Demonstration of high performance millimeter wave GaN-on-Si devices.•First successful preliminary reliability demonstration of sub-200 nm GaN devices.

In this paper, the possibility to use GaN-on-Silicon devices for millimeter wave applications by means of ultrathin barrier layers is reviewed. In particular, an emerging double heterostructure high electron mobility transistor (DHFET) based on AlN/GaN/AlGaN grown on silicon substrate is described, which enables a unique simultaneous achievement of high breakdown voltage and high frequency performance. This configuration system allowed for state-of-the-art GaN-on-Silicon DC, RF output power and noise performances at 40 GHz, paving the way for high performance mmW cost-effective amplifiers. Preliminary reliability assessment has been performed for the first time on this new class of RF devices, showing promising device stability.