SURFACE ENERGY OF FUSION BONDED SILICON NITRIDE TO SILICON

摘要

Transfer of silicon nitride (nitride) membranes to silicon has been performed using hydrophilic fusion bonding. Dry and wet oxidation of the nitride was compared to unoxidized nitride, and silicon-silicon references. Measurements of the surface energies by the blade test indicated that both dry and wet oxidation of the nitride was beneficial to the bond strength increasing the surface energy from 8 mJ/m~2 to more than 50 mJ/m~2. Voids, probably caused by trapped gas, were observed at the bonded interface after bond annealing. The dry oxidized nitride wafers showed less voids than the wet oxidized nitride wafers. The nitride film was successfully transferred to a second silicon wafer by KOH etching. After etching, one wafer was diced into 8x8mm~2 squares without signs of film delamination. This indicates high bond strength.