Compact Modeling of Ballistic Nanowire MOSFETs

Nanowire MOSFETs attract attention due to the probable high performance and the excellent controllability of device current. We present a compact model of ballistic nanowire MOSFET that aids our understanding of physics and the overall properties of the device. The relationship between the gate overdrive and the carrier density is derived and combined with the current expression to yield the current–voltage ($I$ –$V$) characteristics. The subthreshold characteristics and the short channel effect are also discussed. The effects of the quantum capacitance on device characteristics are analyzed. The low-temperature expression is also derived, and the relation to quantum conductance is discussed. The $I$– $V$ characteristics are numerically evaluated and examined, employing a reported subband model. The drain- and gate-bias dependences of device current are shown, and the effects of the quantum capacitance and conductance on these characteristics are indicated.