High frequency performance of nano-scale ultra-thin-body Schottky-barrier n-MOSFETs

Abstract

The high frequency performances of nano-scale ultra-thin-body (UTB) Schottky-barrier nMOSFETs (SB-nMOSFETs) are investigated using 2D full-band self-consistent ensemble Monte Carlo method. The UTB SB-nMOSFET devices offer excellent RF performance with high values of f T and fmax. The significant dependence of f T and fmax on gate voltage and weak dependence on barrier height are demonstrated. Meanwhile, the significant dependence of gm and g ds on both gate voltage and SB height are shown. Moreover, the scalability of f T is outstanding and close to the ideal case (f T ∝ 1/L 2 g ). The high frequency performances of 45 nm channel length SB-nMOSFETs at ballistic transport limit are also investigated. Results show that scattering strongly affects the capacitances Cgs, C gd and C ds . At ballistic transport limit the f T and fmax are almost 10 times larger. The Scattering effects in nano-scale SB-nMOSFETs cannot be neglected.Keywords Monte Carlo, ultra thin body (UTB), Schottky-barrier MOSFETs (SB-MOSFETs), high frequency CitationDu G, Liu X Y, Han R Q. High frequency performance of nano-scale ultra-thin-body Schottky-barrier n-MOSFETs.

The Schottky barrier transistor in emerging electronic devices

“…Multiple authors have explored experimentally and via two-dimensional (2D) technology computed aided design (TCAD) simulations the effects of a metallic source/drain on device performance. A review from 2006 describes earlier devices [7], while Valentin [61][62][63], Pearman [64,65], Raskin [66] and Du [67] have documented the differences in transconductance (g m ), gate capacitance (C gg ) and unity current gain frequency ( f T ) between SBMOSFETs and conventional DSDFETs. All of these investigations show that despite reductions in g m , f T is higher for SBMOSFETs compared to DSDFETs because of significant reductions in C gg .…”