Advances in Diamond Integration for Thermal Management in GaN Power HEMTs

GaN high electron mobility transistors (HEMTs) performance is limited by self-heating during high power operation. Topside nanocrystalline diamond (NCD) layers have been integrated on AlGaN/GaN (HEMTs) to improve thermal management, exhibiting a 20%. decrease in peak channel temperature compared to reference HEMTs in a scalable process. Processing improvements, such as eliminating the SiNx passivation interlayer and developing a sacrificial gate process are being actively pursued. Also, boron doped p+-NCD films were implemented as gate electrodes for the AlGaN/GaN HEMT for a thermally stable heat-spreading gate contact.