Room temperature wafer bonding of silicon, oxidized silicon, and crystalline quartz

The use of plasma immersion as preparation for room temperature wafer bondi ng has been investigated. Silicon wafers have been successfully bonded at r oom temperature after exposure to oxygen or argon plasma. Oxidized silicon wafers and crystalline quartz have been bonded after exposure to oxygen pla sma. The bonded interfaces exhibit very high surface energies, comparable t o what can be achieved with annealing steps in the range of 600-800 degrees C using normal wet chemical activation before bonding. The high mechanical stability obtained after bonding at room temperature is explained by an in creased dynamic in water removal from the bonded interface allowing covalen t bonds to be formed. Electrical measurements were used to investigate the usefulness of plasma bonded interfaces for electronic devices.