Nanowire to Single-Electron Transistor Transition in Trigate SOI MOSFETs

We investigate the effect of symmetrical geometrical constrictions on the electrical characteristics of ultrathin silicon-on-insulator nanowires with a trigate structure using a 3-D numerical quantum simulator. Introducing barriers at the source and drain junctions profoundly alter the device physics and a transition from 1-D to 0-D quantum behavior is observed. The constrictions create resonance levels in the channel region of nanowire due to confinement in the three directions of space, which, in turn, causes oscillation of the I_D-V_GS characteristic. Based on the observed characteristics, we derive a set of parameters that draws the line between 1-D and 0-D quantum behavior of silicon nanowire transistors.