Design and Parametric Variation Assessment of Dopingless Nanotube Field-Effect Transistor (DL-NT-FET) for High Performance

Abstract

\n In this paper, a dopingless nanotube field-effect transistor (DL-NT-FET) has been proposed and its performance analysis is done using a technology computer-aided design (TCAD) tool, ATLAS provided by Silvaco. The elimination of doping is brought in by the application of the charge-plasma (CP) technique. A comparative examination of transfer characteristics (I D -V GS ), transconductance (g m ), gate capacitances (C gs and C gd ), output characteristics (I D -V DS ), output conductance (g ds ), average subthreshold slope (AVSS), the threshold voltage (V t ), the ratio of on-current to off-current (I ON /I OFF ) and on-current has been made by varying the channel length (Lg), radius (R), gate work function (Φ), and temperature. Results revealed that increasing the channel length improves subthreshold slope with greater I ON /I OFF and less threshold voltage. It has been also noticed that increase in the radius of the nanotube or an increase in temperature results in just the opposite effect of that observed in the case of increasing channel length. The I OFF value increases significantly on increasing the temperature while the small degradation in the I ON has been noticed as a result of mobility degradation and velocity saturation. The I ON degrades 15% by increasing the temperature from 200K to 400K. The output conductance g ds also degrades on increasing the temperature. A proliferation of 39% is observed in the C gs at the V GS of 0.45V on increasing the channel length from 20 nm to 35 m whereas no significant changes are observed in the C gd for the same increment in the channel length.