Quantification of wafer bond strength under controlled atmospheres
Kai Takeuchi, Tadatomo Suga
Abstract
Abstract Bond strength is the most reliable criterion of the wafer bonding quality. Water stress corrosion affects the bond strength, corresponding to the measurement atmosphere and residual moisture at the bonding interface. In this study, we developed a new methodology to measure the wafer bond strength including the water stress corrosion effect under the controlled atmospheres, namely, dry atmosphere, wet atmosphere, and vacuum. The developed method experimentally demonstrates the evaluation of the water stress corrosion by the surrounding air and the interfacial water separately. Furthermore, it is also indicated that the water stress corrosion depends on the bonding methods, such that the surface activated bonding using Si intermediate layer has high durability for corrosion and the hydrophilic bonding has low durability. This study will provide a new understanding of the relation between the bonding process and the water stress corrosion effect, especially for the interfacial water.