In this brief report, we discuss novel single crystal structures for electr
onic device and microelectromechanical system applications using processes
that employ selective epitaxial growth (SEG) and silicon-on-insulator (SOI)
wafers. Selective epitaxial growth of silicon is used to provide robust, r
eliable mechanical and electrical contacts between the SOI layer and the su
bstrate. Subsequent removal of the buried oxide results in single crystal s
tructures suspended in air. The films can then be thinned using wet or dry
etching or thinned using sacrificial oxidation steps with the possibility o
f forming ultrathin SOI layers. Diodes formed at the substrate-SEG junction
demonstrate high breakdowns and low leakage indicating good electrical iso
lation between the SOI layer and the substrate. The silicon on air regions
can be used for dual-gate metal-oxide-semiconductor devices, quantum wires,
cantilevers, as a substrate for lattice mismatched epitaxy, ultrathin SOIs
, and lateral field emission tips. (C) 2001 American Vacuum Society.