Multivariate Statistical Analysis of Three-Spatial-Dimension TOF-SIMS Raw Data Sets

• Published in: Analytical chemistry (Washington) 2007-10, Vol.79 (20), p.7719-7726
• Main Authors: Smentkowski, V. S, Ostrowski, S. G, Braunstein, E, Keenan, M. R, Ohlhausen, J. A. (Tony), Kotula, P. G
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Chemistry; Exact sciences and technology; Ions; Mass spectrometry; Multivariate analysis; Spectrometric and optical methods; Spectrum analysis; Three dimensional imaging
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac071019o

Three-spatial-dimension (3D) time-of-flight-secondary ion mass spectrometry (TOF-SIMS) analysis can be performed if an X−Y image is saved at each depth of a depth profile. In this paper, we will show how images reconstructed from specified depths, depth profiles generated from specific X−Y coordinates, as well as three-spatial-dimensional rendering provide for a better understanding of the sample than traditional depth profiling where only a single spectrum is collected at each depth. We will also demonstrate, for the first time, that multivariate statistical analysis (MVSA) tools can be used to perform a rapid, unbiased analysis of the entire 3D data set. In the example shown here, retrospective analysis and MVSA revealed a more complete picture of the 3D chemical distribution of the sample than did the as-measured depth profiling alone. Color overlays of the MVSA components as well as animated movies allowing for visualization (in 3D) from various angles will be provided.