GaN-on-Si HEMTs above 10 W/mm at 2 GHz together with high thermal stability at 325°C

In this paper, the possibility to achieve output power density exceeding 10 W/mm at 2 GHz using 1 mm gate width GaN HEMTs on 4” large diameter Si (111) substrate is demonstrated for the first time. Additionally, storage tests at 325°C reveal the high thermal stability of these devices which we attribute to the in-situ grown SiN cap layer. These data are a first step towards a cost-effective high RF power density for high reliability GaN-on-Si HEMT technology.