Demonstration of high thermal performance GaN-on-graphite composite bonded substrate for application in III-V nitride electronics

Superior thermal performance of GaN/graphite composite (GC) bonded substrates having an ultralow thermal resistance (Rth) has been demonstrated. Thermal transition in GaN-on-GC features fast relaxation process in GaN and slow case in GC, respectively. The temperature plateau at the GaN/GC interface indicates the Rth across this interface is quite small and hence can be ignored. High-quality bonding interface and homogenous layer properties were obtained for the GaN-on-GC system. This favors the acoustic phonon transport and is bound to contribute to the outstanding thermal performance. The GaN/GC bonded substrate provides a promising candidate for thermal management applications in GaN-based electronics.