Investigation on the bonding quality of GaN and Si wafers bonded with Mo/Au nano-layer in atmospheric air

A room-temperature bonding process based on Mo/Au nano-layer was applied to bond GaN on Si wafers in atmospheric air. The analytical test results show that a low bonding defect density (0.2%) and a strong bonding strength (10.0 MPa) were achieved for the GaN/Si sample bonded with Mo/Au nano-layer. The bonding defect density of the bonded GaN/Si sample remained mostly unchanged and each of Au/Au, Au/Mo/GaN and Au/Mo/Si interfaces had a strong adhesion strength after 1000-cycles thermal cycling testing. In addition, Mo/Au ohmic contact on n-type GaN was realized by Ar⁺ ion beam treatment on the GaN surface.