Fabrication of Silicon and Oxide Membranes Over Cavities Using Ion-Cut Layer Transfer

Silicon and oxide membranes were fabricated using an ion-cut layer transfer process, which is suitable for sub-micron-thick membrane fabrication with good thickness uniformity and surface micro-roughness. After hydrogen ions were implanted into a silicon water, the implanted wafer was bonded to another wafer that has patterned cavities of various shapes and sizes. The bonded pair was then heated until hydrogen-induced silicon layer cleavage occurred along the implanted hydrogen peak concentration, resulting in the transfer of the silicon layer from one wafer to the other. Using this technique, we have been able to form sealed cavities and channels of various shapes and sizes up to 50- [micro] m wide, with a 1.6- [micro] m-thick silicon membrane. As a process variation, we have also fabricated silicon dioxide membranes for optically transparent applications. [506] Index Terms--Ion-cut, layer transfer, micro channels, oxide membrane, sealed cavities, silicon membrane, wafer bonding.