Nanofabrication of top-gated carbon nanotube-based transistors: Probing electron-electron interactions in one-dimensional systems

• Published in: Journal of materials research 2006-11, Vol.21 (11), p.2916-2921
• Main Authors: Sulpizio, J.A., Bandić, Z.Z., Goldhaber-Gordon, D.
• Format: Article
• Language: English
• Subjects: Devices; Lithography
• ISSN: 0884-2914; 2044-5326
• DOI: 10.1557/jmr.2006.0361

Carbon nanotubes are interesting for studying the remarkable electronic properties of one-dimensional (1D) quantum systems. Electron flow in such systems is not described by Fermi liquid theory—restricted dimensionality leads to the appearance of collective excitations—or Luttinger liquid behavior. Previous studies have probed Luttinger liquid behavior by tunneling into or between one-dimensional systems. We propose to extend these studies by using narrow top gates to introduce tunable tunnel barriers within nanotubes. We report on the scalable fabrication of carbon nanotube-based transistors with nanowire top gates. We have used electron-beam lithography (EBL) to create single-walled carbon nanotube (SWNT) transistors with source-drain spacings down to 200 nm and with sub-30 nm metal top gates for creating tunable tunnel barriers. The top metal gate is isolated from the nanotube by a thin aluminum oxide layer deposited by atomic layer deposition. We fabricated chips with 100 devices using multiple electron-beam lithography alignment steps and achieved overall placement better than 30 nm. The details of top-gated SWNT transistor fabrication are presented, and initial transport measurements on fabricated devices are discussed.