Temperature Dependence of Electrical Characteristics of Carbon Nanotube Field-Effect Transistors: A Quantum Simulation Study

TL;DR

This study uses advanced quantum simulations to analyze how temperature variations impact the electrical performance of carbon nanotube FETs, revealing key effects on conductance, current ratios, and short channel effects.

Contribution

It introduces a comprehensive 2D quantum simulation approach to investigate temperature effects on CNTFETs, providing detailed insights into their electrical characteristics.

Findings

Drain conductance and on-current increase with temperature.

On/off-current ratio decreases as temperature rises.

Subthreshold swing and DIBL are linearly correlated and affected by temperature.

Abstract

By developing a two-dimensional (2D) full quantum simulation, the attributes of carbon nanotube field-effect transistors (CNTFETs) in different temperatures have been comprehensively investigated. Simulations have been performed by employing the self-consistent solution of 2D Poisson-Schrodinger equations within the nonequilibrium Green's function (NEGF) formalism. Principal characteristics of CNTFETs such as current capability, drain conductance, transconductance, and subthreshold swing (SS) have been investigated. Simulation results present that the drain conductance and on-current of the CNTFET increases as temperature raises from 250 to 500 K. Meanwhile the on-/off-current ratio deteriorated due to faster growth in off-current. Also the effects of temperature on short channel effects (SCEs) such as drain-induced barrier lowering (DIBL) and threshold voltage roll-off have been studied. Results show that the subthreshold swing and DIBL parameters are almost linearly correlated, so the degradation of these parameters has the same origin and can be perfectly influenced by the temperature.