Suppression of ambipolar leakage current in Schottky barrier MOSFET using gate engineering

Abstract

A novel asymmetric isolated gates dopant segregated Schottky barrier MOSFET (AIG DS-SBMOS) for the suppression of ambipolar leakage current (IAMB) using gate engineering is reported. The AIG DS-SBMOS consists of a dopant segregated source/drain with two asymmetric isolated gates (control gate, fixed gate) having different metal work functions. The control gate is used to control current conduction by modifying the Schottky barrier height and width at the source/channel junction; while, the fixed gate modulates the drain side Schottky barrier to the suppress IAMB caused by hole injection in the off-state condition. In contrast to the conventional SBMOS and DS-SBMOS that suffer from ambipolarity, the proposed device is free from severe IAMB. Moreover, the proposed AIG DS-SBMOS has a high ION/IOFF ratio of 107 with nearly the same ION and subthreshold swing as that of the DS-SBMOS. The proposed device structure is especially beneficial for nanowire-based transistors.