Evaluation of Au/a-Si eutectic wafer level bonding process

This paper presents a new method for achieving Au/aSi (amorphous Si) eutectic wafer-level bonding. The Si-Glass wafer bonding was conducted with Au layer patterned on glass wafer and amorphous Si layer on silicon wafer. The amorphous Si here was transformed from the single crystal silicon by the Argon implantation process. A novel torsional strength test structure was proposed and applied for characterization of Au/Si bonding strength. The anti-corrosion property of the bonded wafers was evaluated in the KOH thinning process. The performance of the Au/Si bond with respect to the bond area were studied in detail. Results indicated that the Au/a-Si bonding exhibited much better performance compared with the conventional Au/c-Si bonding.