Improvement of carrier ballisticity in junctionless nanowire transistors

Abstract

In this work we show that junctionless nanowire transistor (JNT) exhibits lower degree of ballisticity in subthreshold and higher ballisticity above threshold compare to conventional inversion-mode transistors, according to quantum mechanical simulations. The lower degradation of the ballisticity above threshold region gives the JNT near-ballistic transport performance and hence a high current drive. On the other hand, lower ballisticity in subthreshold region helps reducing the off-current and improves the subthreshold slope. A three-dimensional quantum mechanical device simulator based on the nonequilibrium Green’s function formalism in the uncoupled mode-space approach has been developed to extract the physical parameters of the devices.