The edge of a thin SOI (silicon on insulator) film was used to form a
very narrow Si-MOS inversion layer. The ultra-thin SOI film was formed
by local oxidation of SIMOX wafer. The thickness of the SOI film is l
ess than 15 nm, i.e., the channel width is narrower than 15 nm. At low
temperatures, clear and large conductance oscillations were seen in t
his edge channel MOSFET. These oscillations are explained by Coulomb b
lockade effects in the narrow channel with several effective potential
barriers, since the SOI film is so thin that the channel current is s
eriously affected by small potential fluctuations in the channel. Thes
e results suggest that the channel current in edge quantum wire MOS FE
T can be cut off even with a small controlled potential change. Furthe
rmore, we fabricated a double-gate edge channel Si-MOSFET. In this dev
ice, the channel current can be controlled in two ways. One way is to
control the electron number inside the isolated electrodes. The other
way is to control the threshold voltage of MOSFET. This device enables
us to control the phase of Coulomb oscillation.