Room-temperature wafer bonding with smooth Au thin film in ambient air using Ar RF plasma activation

Quartz glass wafers with smooth Au thin film (thickness: 30 nm, surface roughness Ra: 0.34 nm) were successfully bonded in ambient air at room temperature after Ar RF plasma activation process. The room temperature bonded glass wafers without any heat treatment showed a sufficiently high die-shear strength of 47~70 MPa. The application of this process to heterogeneous integration of GaAs on SiC enables improved thermal management in high power semiconductor lasers.