“…The unique feature of today's SOI wafers is that they have a buried silicon oxide (Buried Oxide, or BOX) layer extending across the entire wafer, just below a surface layer of device-quality singlecrystal silicon.. At the present time, most SOI wafers are fabricated by use of one of two basic approaches. SOI wafers may be fabricated with the SIMOXTM ( [124,123] Alternately, SOI wafers can be fabricated by bonding a device quality silicon wafer to another silicon wafer (the "handle" wafer) that has an oxide layer on its surface. [145,144] the pair is then split apart, using a process that leaves a thin (relative to the thickness of the starting wafer), device-quality layer of single crystal silicon on top of the oxide layer (which has now become the BOX) on the handle wafer.…”