Influence of H2O in bonding interfaces on bonding strength of plasma-activated bonded silicon oxide

Many studies of the plasma-activated bonding, bonding strength have focused on the wafer surface. However, no studies have reported on how moisture in the film affects the bond strength. Therefore, in this study, we evaluated the effect of moisture in the membrane on bonding strength. The results indicated that the bonding strength was higher for the film with higher water content, and that an oxide film with higher water content expanded during heat treatment after bonding. We propose a new model in which film expansion contributes to higher bonding strength.