A New NIST Database for the Simulation of Electron Spectra for Surface Analysis (SESSA): Application to Angle-Resolved X-ray Photoelectron Spectroscopy of HfO2, ZrO2, HfSiO4, and ZrSiO4 Films on Silicon

Journal Article · Fri Sep 09 00:00:00 EDT 2005 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2062946· OSTI ID:20719254

Powell, C J ^[1]; Smekal, W; Werner, W S.M. ^[2]

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1. Surface and Microanalysis Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-8370 (United States)
2. Institut fuer Allgemeine Physik, Vienna University of Technology, Wiedner Hauptstrasse 8-10, A-1040 Vienna (Austria)

We describe a new NIST database for the Simulation of Electron Spectra for Surface Analysis (SESSA). This database provides data for the many parameters needed in quantitative Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). In addition, AES and XPS spectra can be simulated for layered samples. The simulated spectra, for layer compositions and thicknesses specified by the user, can be compared with measured spectra. The layer compositions and thicknesses can then be adjusted to find maximum consistency between simulated and measured spectra. In this way, AES and XPS can provide more detailed characterization of multilayer thin-film materials. We report on the use of SESSA for determining the thicknesses of HfO2, ZrO2, HfSiO4, and ZrSiO4 films on Si by angle-resolved XPS. Practical effective attenuation lengths (EALs) have been computed from SESSA as a function of film thickness and photoelectron emission angle (i.e., to simulate the effects of tilting the sample). These EALs have been compared with similar values obtained from the NIST Electron Effective-Attenuation-Length Database (SRD 82). Generally good agreement was found between corresponding EAL values, but there were differences for film thicknesses less than the inelastic mean free path of the photoelectrons in the overlayer film. These differences are due to a simplifying approximation in the algorithm used to compute EALs in SRD 82. SESSA, with realistic cross sections for elastic and inelastic scattering in the film and substrate materials, is believed to provide more accurate EALs than SRD 82 for thin-film thickness measurements, particularly in applications where the film and substrate have different electron-scattering properties.

• OSTI ID: 20719254
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 788; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALGORITHMS
AUGER ELECTRON SPECTROSCOPY
CHEMICAL ANALYSIS
COMPUTERIZED SIMULATION
ELECTRON EMISSION
ELECTRON SPECTRA
HAFNIUM OXIDES
HAFNIUM SILICATES
INELASTIC SCATTERING
LAYERS
MEAN FREE PATH
MEASURING METHODS
SEMICONDUCTOR MATERIALS
SILICON
SUBSTRATES
THICKNESS
THIN FILMS
X-RAY PHOTOELECTRON SPECTROSCOPY
ZIRCONIUM OXIDES
ZIRCONIUM SILICATES