Wafer bonding: an overview

Wafer bonding started as a specific way to fabricate inexpensive thick (>1 /spl mu/m) film silicon-on-insulator (SOI) materials of high quality. In the meantime, also ultrathin SOI layers can be produced by wafer bonding and proper thinning techniques. In addition, silicon wafer bonding has shown to be a versatile technique for fabricating sensors and actuators. Especially in this area it is desirable to perform bonding at a temperature as low as possible. Wafer bonding may also be used to produce combinations of materials which may differ in terms of structure, crystallinity or lattice constant. The last feature allows the fabrication of III-V compound combinations which are not lattice matched and may be used for vertical cavity surface emitting lasers.