SIMS2015 Session ID-ThP: Image and Data Fusion Poster Session
Time Period ThP Sessions | Topic ID Sessions | Time Periods | Topics | SIMS2015 Schedule
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ID-ThP-1 Influences of Yield and Damage Cross-Section on Imaging Analysis of Organic Molecules by Bi cluster TOF-SIMS
Rie Shishido (Tohoku University, Japan); Makiko Fujii, Toshio Seki, Takaaki Aoki, Jiro Matsuo (Kyoto University, Japan); Shigeru Suzuki (Tohoku University, Japan) Analytical techniques for soft-materials have been remarkably advanced. Among those techniques, static secondary ions mass spectrometry (SSIMS) with high sensitivity and high spatial resolution is attracted attention as one of the most useful methods for macromolecules on solid surface. It has been reported that damage cross-section by projectiles of cluster ions has not increased so much or rather sometimes decreased in comparison to that of monomer ions. In addition, imaging analysis of organic materials by Bi cluster TOF-SIMS which is one of the conventional SSIMS has been performed in the last ten years. Therefore, it is important to establish the analysis conditions in the SSIMS imaging ions are found. In this study, 1, 2-distearoyl-sn-glycero-3-phosphocholine (DSPC) which is one of the typical lipids in human living body, and N,N'-Di(1-naphthyl)-N,N'-diphenylbenzidine (C44H32N2, NPD) and 4,4’,4’’-Tri[2-naphthyl (phenyl)amino] triphenylamine (C66H48N4, 2-TNATA) which are one of organic electro-luminescence, were analyzed by TOF-SIMS. In the analysis, we focused influences of the species of the primary Bi ions on the yields of secondary ions, damage cross-section and spatial resolution. Samples were thin films of DSPC, NPD and 2-TNATA spin-coated onto the surfaces of a clean Si wafer to acquire the mass spectra for evaluating yield of secondary ions and damage cross-section. Also, the pattered samples to obtain the mass images for evaluating spatial resolution were prepared. TOF-SIMS measurements were performed in a TOF.SIMS 5 instrument (ION-TOF GmbH). The pulsed primary Bi1+, Bi3+ and Bi32+ ion beams accelerated 25 kV was bombarded to the samples and the positively charged secondary ions were analyzed. These thin films were analyzed in the high-current bunched mode. Secondary ion images of patterning samples were collected in the non-bunched burst alignment mode. The present results show that the incidence of large cluster ions increases yields of secondary ions, and yields of secondary ions strongly depend on the molecule species. High resolution imaging is achieved using Bi32+ ions due to high-sensitive detection of the secondary ions, and the spatial resolution depends generally on yields of the secondary ions. It is remarked that the primary ion species for the highest yields of secondary ions depend on primary ions dose density because damage cross-section of Bi32+ ions is higher than that of Bi1+ and Bi3+ ions. Consequently, it is concluded that selection of the primary ion species is crucial to SSIMS analysis of macromolecules by Bi cluster ions. |
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ID-ThP-2 Implementing Segment and Pixel Based Fusion Methods to Improve Spatial Resolution and Spectral Content In ToF-SIMS Images
Tammy Milillo (University at Buffalo, The State University of New York); Mary Miller (Michigan Tech Research Institute); Remo Fischione (CUBRIC Inc.); Joseph A. Gardella (University at Buffalo, The State University of New York) The size of the dataset created from the chemical image map is a limiting factor to applying the imaging capabilities of the ToF-SIMS. ToF-SIMS has the ability to obtain intensity values for trace elemental concentrations contained in the chemical image map at every pixel in the image. The size of the resulting dataset can be reduced by applying a variety of multivariate statistical techniques. This study avoids the data altering aspects of these techniques, by applying image fusion algorithms commonly used in remote sensing, environmental ecology and geography. Two classes of algorithms, when applied, could provide both pixel level information and structure/feature information by improving the spatial resolution of the ToF-SIMS image to be comparable to that found in the SEM image of a standard Cameca test grid. The Munechika fusion improves the pixel level information obtained, and the segment/region based fusion clearly identifies notable features or regions in the test grid. The methods developed and discussed here could be invaluable in the analysis of biological samples, and allow for the identification of particular cellular regions or chemically distinct regions by allowing for the creation of a hybrid image that contains both improved spatial resolution and chemical information. |