Planar CMOS transistors on bulk silicon wafers are expected to reach their
limits at gate sizes about 50nm in 2005-06. Many of the process and materia
ls constraints that combine to force this change in technology path are rel
axed or removed for CMOS devices fabricated on SOI wafers. This article out
lines the principal issues limiting junction formation for sub-100nm CMOS o
n bulk silicon and presents an alternative roadmap using SOI wafers. An SOI
wafer fabrication technology is described that provides a room temperature
, atomic layer cleaving process with unprecedented levels of control on sil
icon layer thickness, as well as a clear path for extension towards the ult
rathin SOI regime.