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

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 I_OFF 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 I_ON/I_OFF ratio of ~10⁹ and SS of 60.8 mv/dec whereas diameter of 0.55 nm results into I_ON/I_OFF ratio of ~10¹¹ with SS of 58.5 mv/dec. Optimized parameters are proposed for low power applications in terms of I_OFF and SS. ED-SBCNTFET has been analysed for various process parameters and it has been demonstrated to be less sensitive to process variations.