AVS 50th International Symposium
    Applied Surface Science Wednesday Sessions
       Session AS-WeP

Paper AS-WeP12
Multivariate Statistical Analysis of Time of Flight Secondary Ion Mass Spectrometry Images, Looking beyond the Obvious

Wednesday, November 5, 2003, 11:00 am, Room Hall A-C

Session: Poster Session
Presenter: V.S. Smentkowski, General Electric Global Research Center
Authors: V.S. Smentkowski, General Electric Global Research Center
J.A. Ohlhausen, Sandia National Laboratories
M.R. Keenan, Sandia National Laboratories
P.G. Kotula, Sandia National Laboratories
Correspondent: Click to Email
Analytical instrumentation such as Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) provides a tremendous quantity of data since an entire mass spectrum is saved at each pixel in an ion image. The analyst often selects only a few species for detailed analysis; the majority of the data are not utilized. Researchers at Sandia National Laboratory (SNL) have developed a powerful Multivariate Statistical Analysis (MVSA) tool kit named AXSIA (Automated eXpert Spectrum Image Analysis) that looks for trends in complete data sets (eg. analyzes the entire mass spectrum at each pixel). A unique feature of the AXSIA tool kit is the generation of intuitive results (eg. negative peaks are not allowed in the spectral response). The robust statistical process is able to unambiguously identify all of the spectral features uniquely associated with each distinct component throughout the data set. GE and Sandia used AXSIA to analyze raw data files generated on an Ion Tof IV ToF-SIMS instrument. Select examples will be shown. The MVSA toolkit positively identified metallic contaminants within a defect in a polymer sample. These metallic contaminants were not identifiable using standard data analysis protocol. We will also demonstrate that the MVSA toolkit is able to analyze images collected using the burst pulsing mode. This work was funded in part under CRADA SC00/01609 PTS 1609.02 Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.