Analytic model for subthreshold channel potential and threshold voltage of the Schottky-barrier surrounding-gate MOSFETS

The threshold voltage, V
th
, of a surrounding-gate (SG) Schottky-barrier (SB) metal-oxide-semiconductor field-effect transistor (MOSFET) is investigated. An analytical expression for surface potential is obtained by solving Poisson's equation. Based on the potential model, an analytical expression for V
th
is achieved, with quantum mechanical effects and SB lowering effect included. It is found that V
th
will be raised by quantum mechanical effects and lowered by SB lowering effect. It is also found that, the influence of channel length on V
th
is complicated; when the channel length is 20 nm, V
th
is the smallest.