Bridging the Performance and Reliability Gap of GaN-on-Si with GaN-on-SiC RF HEMTs by Efficient Electric Field Management Using a Novel p-type Oxide Passivation

In this paper, we demonstrate the use of a novel p-type passivation to significantly enhance the reliability and performance of GaN-on-Si RF HEMTs, overshooting that of GaN-on-SiC RF HEMTs. The proposed p-type passivation when used over the existing in-situ SiN passivation helps in efficient electric field management by reducing the channel electric field peak which is the root cause of device reliability issues. The novel passivation scheme significantly reduced current collapse, improved breakdown voltage, and suppressed self-heating in the devices compared to the conventional SiN only passivated devices. DC and large signal characteristics were also improved, resulting in GaN-on-Si RF HEMTs with a potential to match and even improve reliability and performance aspects of GaN-on-SiC RF HEMTs.