Low temperature fusion bonding with high surface energy using a wet chemical treatment

摘要

Described is a wet chemical surface treatment involving NH4OH that enables extremely strong direct bonding of two wafer such as semiconductors (e.g., Si) to insulators (e.g., SiO2) at low temperatures (less than or equal to 400° C.). Surface energies as high as ˜4835±675 mJ/m2 of the bonded interface have been achieved using some of these surface treatments. This value is comparable to the values reported for significantly higher processing temperatures (less than 1000° C.). Void free bonding interfaces with excellent yield and surface energies of ˜2500 mJ/m2 have also be achieved herein.