Additive Influence of Top Metal Contact and Alumina Deposition on the Threshold Voltage of Suspended Carbon Nanotube Field-Effect Transistors

Abstract

One-dimensional nanostructures such as carbon nanotubes offer excellent properties useful for applications in gas sensors, piezoresistive devices, and radio frequency resonators. Considering their nanoscale form factor, carbon nanotubes (CNTs) are highly sensitive to surface adsorbents. This study presents the fabrication flow of CNT devices with extended passivated areas around electrical contacts between the CNT and source and drain electrodes. These types of structures could help in understanding the intrinsic CNT response by eliminating the analyte impact on the Schottky barrier regions of the CNT field-effect transistors (CNTFETs). The influence of multiple processing conditions on the electronic properties of CNTFETs with a suspended individual CNT used as the CNTFET channel is presented. Our findings show a threshold voltage shift in CNT I SD–V g characteristics following the metal deposition and alumina atomic layer deposition.