Titania/alumina bilayer gate insulators for InGaAs metal-oxide-semiconductor devices

Ahn, J., Geppert, I., Gunji, M., Holland, M., Thayne, I. , Eizenberg, M. and McIntyre, P.C. (2011) Titania/alumina bilayer gate insulators for InGaAs metal-oxide-semiconductor devices. Applied Physics Letters, 99(23), p. 232902. (doi: 10.1063/1.3662966)

Abstract

We describe the electrical properties of atomic layer deposited TiO₂/Al₂O₃ bilayer gate oxides which simultaneously achieve high gate capacitance density and low gate leakage current density. Crystallization of the initially amorphous TiO₂ film contributes to a significant accumulation capacitance increase (∼33%) observed after a forming gas anneal at 400 °C. The bilayer dielectrics reduce gate leakage current density by approximately one order of magnitude at flatband compared to Al₂O₃ single layer of comparable capacitance equivalent thickness. The conduction band offset of TiO₂ relative to InGaAs is 0.6 eV, contributing to the ability of the stacked dielectric to suppress gate leakage conduction.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Thayne, Prof Iain and Holland, Dr Martin
• Authors: Ahn, J., Geppert, I., Gunji, M., Holland, M., Thayne, I., Eizenberg, M., and McIntyre, P.C.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Applied Physics Letters
• Publisher: American Institute of Physics
• ISSN: 0003-6951
• Published Online: 05 December 2011
• Copyright Holders: Copyright © 2011 American Institute of Physics
• First Published: First published in Applied Physics Letters 99(23):232902
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher