A new analytical method for characterising the bonding environment at rough interfaces in high-k gate stacks using electron energy loss spectroscopy

Mendis, B.G., MacKenzie, M. and Craven, A.J. (2010) A new analytical method for characterising the bonding environment at rough interfaces in high-k gate stacks using electron energy loss spectroscopy. Ultramicroscopy, 110(2), pp. 105-117. (doi: 10.1016/j.ultramic.2009.09.013)

Abstract

Determining the bonding environment at a rough interface, using for example the near-edge fine structure in electron energy loss spectroscopy (EELS), is problematic since the measurement contains information from the interface and surrounding matrix phase. Here we present a novel analytical method for determining the interfacial EELS difference spectrum (with respect to the matrix phase) from a rough interface of unknown geometry, which, unlike multiple linear least squares (MLLS) fitting, does not require the use of reference spectra from suitable standards. The method is based on analysing a series of EELS spectra with variable interface to matrix volume fraction and, as an example, is applied to a TiN/poly-Si interface containing oxygen in a HfO2-based, high-k dielectric gate stack. A silicon oxynitride layer was detected at the interface consistent with previous results based on MLLS fitting.

• Item Type: Articles
• Keywords: Electron energy loss spectroscopy (EELS), scanning transmission electron microscopy (STEM), spectrum imaging, high-k dielectrics
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: MacKenzie, Dr Maureen and Craven, Professor Alan and Mendis, Dr Budhika
• Authors: Mendis, B.G., MacKenzie, M., and Craven, A.J.
• Subjects: Q Science > QC Physics
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Ultramicroscopy
• Publisher: Elsevier
• ISSN: 0304-3991
• ISSN (Online): 1879-2723
• Published Online: 26 September 2009
• Copyright Holders: Copyright © 2009 Elsevier
• First Published: First published in Ultramicroscopy 110(2):105-117
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
35067	1	Chemistry, structure and bonding in high-k gate oxide stacks	Alan Craven	Engineering & Physical Sciences Research Council (EPSRC)	GR/S44280/01	Physics and Astronomy
41337	1	SuperSTEM - the UK aberration corrected STEM facility	Alan Craven	Engineering & Physical Sciences Research Council (EPSRC)	EP/D040205/1	Physics and Astronomy