Determination of the electrostatic lever arm of carbon nanotube field effect transistors using Kelvin Force Microscopy

TL;DR

This study uses Kelvin Force Microscopy to quantitatively determine the electrostatic lever arm of carbon nanotube FETs, providing a new method for precise electrostatic characterization at room temperature.

Contribution

It introduces a novel application of KFM to accurately measure the electrostatic lever arm of CNTFETs, accounting for probe capacitance effects.

Findings

Electrostatic lever arm determined by KFM agrees with Coulomb blockade measurements.

KFM maps reveal the influence of backgate polarization on electrostatic properties.

Method enables quantitative electrostatic analysis of CNTFETs at room temperature.

Abstract

We use Kelvin Force Microscopy (KFM) to study the electrostatic properties of single-walled Carbon Nanotube Field Effect Transistor devices (CNTFETs) with backgate geometry at room temperature. We show that KFM maps recorded as a function of the device backgate polarization enable a complete phenomenological determination of the averaging effects associated with the KFM probe side capacitances, and thus, to obtain KFM measurements with quantitative character. The value of the electrostatic lever arm of the CNTFET is determined from KFM measurements, and found in agreement with transport measurements based on Coulomb blockade.