Room-temperature bonding for hermetic sealing using electroplated Au seal rings with ultra-smooth surface

We evaluated room temperature bonding characteristics of electroplated Au surfaces smoothed by lift-off method and imprint method. As a result, smoothed surfaces can make a strong bonding; on the other hand electroplated rough surface make a very weak bonding. In TEM observation, no delamination was observed at the bonding interface, which was bonded at room temperature using a smooth surface replicated by the lift-off process. Hermeticity of bonding interface prepared by smoothed surfaces was evaluated by diaphragm structures. As a result, good hermetic sealing was confirmed using the smooth surface replicated by the lift-off method.