Direct wafer bonding of GaN-SiC for high power GaN-on-SiC devices

GaN-on-SiC has been very attractive for high-power GaN device owing to the high thermal conductivity of SiC substrate. However, the transition layer with a low-thermal-conductivity for epitaxial growth of GaN layers cause a high thermal barrier resistance at the interface between GaN and SiC. This work employed surface activated bonding (SAB) method to fabricate GaN-on-SiC structure without a conventional transition layer via direct wafer bonding at room temperature. The interfaces bonded at room temperature was investigated to confirm the structure. Also, the interface annealed at 200 °C was inspected to confirm the possible changes at a working temperature.