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.