Surface preparation for selective silicon fusion bonding

An apparatus and method for a silicon-based Micro-Electro Mechanical System (MEMS) device, including a pair of silicon cover structures each having a substantially smooth and planar contact surface formed thereon; a silicon mechanism structure having a part thereof that is movably suspended relative to a relatively stationary frame portion thereof, the frame portion being formed with substantially parallel and spaced-apart smooth and planar contact surfaces; a relatively rough surface disposed between the contact surfaces of the covers and corresponding surfaces of the movable part of the mechanism structure; and wherein the contact surfaces of the cover structures form silicon fusion bond joints with the respective contact surfaces of the mechanism frame.