Analysis of electrostatic doped Schottky barrier carbon nanotube FET for low power applications

Abstract

This paper presents the analysis of electrostatic doped Schottky barrier carbon nanotube FET (ED-SBCNTFET) for low power applications. Electrostatic doping is introduced in intrinsic CNT as a channel material which reduces the process complexity; moreover dynamic configuration provides symmetric transfer characteristics for n-type and p-type for ED-SBCNTFET. Simulation results demonstrate that ED-SBCNTFET is better than conventional CNTFET in terms of IOFF and subthreshold swing (SS) which makes it suitable for low power applications. Simulations are performed and sensitivity analysis is carried out for CNT diameter, effective oxide thickness (EOT), high-k dielectric and polarity gate bias. It is observed that CNTs are most sensitive to diameter, since CNT with diameter 0.85 nm exhibits ION/IOFF ratio of ~109 and SS of 60.8 mv/dec whereas diameter of 0.55 nm results into ION/IOFF ratio of ~1011 with SS of 58.5 mv/dec. Optimized parameters are proposed for low power applications in terms of IOFF and SS. ED-SBCNTFET has been analysed for various process parameters and it has been demonstrated to be less sensitive to process variations.