CNT material cleaning and device fabrication

Aligned semiconducting carbon nanotubes (CNTs) are a promising material candidate for next-generation field-effect transistors (FETs) due to their unique intrinsic properties, e.g. ballistic transport, excellent charge carrier mobility and high thermal conductivity. Significant progress in the recent years in CNT purification, assembly from solution into densely aligned arrays and subsequent integration in devices demonstrates that the CNT material remains not only scientifically attractive but offers a technologically feasible pathway towards high-performing FETs.

In this work you will contribute to the establishment of a CNT device technology platform at imec with the focus on material development and characterization. The goal of this work is twofold:

(1) Set up and optimize a protocol for optical lithography for aligned CNT device fabrication.

(2) Examine the contamination level and options of polymer residue removal for the CNT devices.

Residual polymer, which might not be fully removed from the CNT material during the fabrication, is one of the issues of the contact lithography module development and therefore, a follow up cleaning process is required. The major challenge of this work is to enable polymer residue removal with minimal damage to the channel material and assess the cleaning effect using e.g. AFM, Raman, XPS and electrical measurements. Next to the standard solvent and anneal based cleaning approaches, remote plasma technique will be explored as an alternative method for the polymer residue removal. Finally, the process of optical lithography-based fabrication and its influence on the electrical properties of the CNT material will be evaluated.