Performance optimization of MOS-like carbon nanotube-FETs based on electrostatic doping

摘要

Due to carriers Band-To-Band-Tunneling (BTBT) through channel-source/drain contacts, Conventional MOS-like Carbon Nanotube Field Effect Transistors (C-CNFETs) suffer from ambipolar conductance, which deteriorates the device performance greatly. In order to reduce such ambipolar behavior, a novel device structure based on electrostatic doping is proposed. The Non-Equilibrium Green's Function (NEGF) formalism based simulation results show that, with proper choice of tuning voltage, such electrostatic doping strategy can not only reduce the ambipolar conductance but also improve the sub-threshold performance, which are both quite desirable in circuit design to reduce the system power and improve the frequency as well. Further study reveals that the performance of the proposed design depends highly on the choice of tuning voltage value, which should be paid with much attention to obtain a proper trade-off between power and speed in application.