Optimized nano-scaled drain- and gate-engineered Schottky barrier MOSFET with improved ambipolarity and RF characteristics

Abstract

In this work, a novel Schottky Barrier MOSFET (SB-MOSFET) structure is presented. The proposed device consists of a dual-material gate and electrostatically doped drain, and the device is denoted as Gate and Drain Engineered Schottky Barrier MOSFET (GDE-SBMOSFET). The use of a dual-material gate and electrostatically doped drain enhances the ON state performance and short channel performance, respectively, in comparison to state-of-the-art devices. By optimizing the gate and drain metal workfunction, the proposed device technology node can be scaled below 22 nm without exhibiting performance degradation. The optimized values of the metal workfunction of the drain and tunnel gate (TG) improve the parameters, such as the ON current and ON/OFF current ratio, which have been increased 26- and 10-fold in comparison to conventional SBMOSFETs. Additionally, a substantial enhancement of 28% and 4% in the SS of the proposed GDE-SBMOSFET has been achieved in comparison to that of the DSL and conventional SB-MOSFET, respectively. The ac investigation has shown that the cut-off frequency (f_T) in the GDE-SBMOSFET (∼510 GHz) has increased 51 and 2 times as compared to that of the conventional SB-MOSFET (∼10 GHz). Further, the GDE-SBMOSFET has higher scalability and reduced ambipolarity, and doping-related issues caused by doped regions are absent in the proposed device.