Bias-Dependent Contact Resistance Characterization of Carbon Nanotube FETs

An extraction method for a bias-dependent contact resistance is presented and applied to simulation and experimental data of single and multi-tube carbon nanotube field effect-transistors (CNTFETs) with different channel lengths and Schottky barrier heights. The method relies on the individual device characteristics, i.e., it can be applied to different CNTFET technologies. Furthermore, it does not require the fabrication of test structures or challenging model calibration. The extracted values correspond to reference values in simulations and are as well similar to the ones obtained for the fabricated devices with other more expensive, technology-specific analytical and physics-based approaches. Hence, the extraction method presented here can be considered as an efficient and accurate alternative. By revealing the bias-dependence of the contact parameters, rarely reported in the literature, the nature of the Schottky barriers can be characterized and the contact transparency can de identified.