Comparison of simulation models for the coaxially-gated carbon-nanotube field-effect transistor

Carbon-nanotube field-effect transistors (CNFETs) have received great attention as possible successors to metal-oxide-semiconductor field-effect transistors (MOSFETs) beyond the sub-10 nm era. In this work, numerical simulations were performed on single-walled semiconducting CNFETs using a FETToy simulator and a compact model with or without a smoothing parameter. The discontinuity in the derivative of the surface potential with respect to VGS in the compact model can be remedied by employing a simple smoothing parameter. The simulated output characteristics of CNFETs with a 1.5-nm-thickgate insulator and a 3-nm-diameter nanotube channel exhibited the advantage of using a smoothing parameter. Our results show fairly good matches between the FETToy model and the compact model with a smoothing parameter of less than 5 × 10−4.