Chemical Imaging Beyond the Diffraction Limit: Experimental Validation of the PTIR Technique

Authors

  • Basudev Lahiri,

    1. NIST, Center for Nanoscale Science and Technology, Gaithersburg, 100 Bureau Drive, Stop 6204, MD 20899, USA
    2. University of Maryland, Institute for Research in Electronics and Applied Physics (IREAP), College Park, MD 20742, USA
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  • Glenn Holland,

    1. NIST, Center for Nanoscale Science and Technology, Gaithersburg, 100 Bureau Drive, Stop 6204, MD 20899, USA
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  • Andrea Centrone

    Corresponding author
    1. NIST, Center for Nanoscale Science and Technology, Gaithersburg, 100 Bureau Drive, Stop 6204, MD 20899, USA
    2. University of Maryland, Institute for Research in Electronics and Applied Physics (IREAP), College Park, MD 20742, USA
    • NIST, Center for Nanoscale Science and Technology, Gaithersburg, 100 Bureau Drive, Stop 6204, MD 20899, USA.
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Errata

This article is corrected by:

  1. Errata: Chemical Imaging Beyond the Diffraction Limit: Experimental Validation of the PTIR Technique Volume 9, Issue 11, 1876, Article first published online: 3 June 2013

Abstract

Photothermal induced resonance (PTIR) has recently attracted great interest for enabling chemical identification and imaging with nanoscale resolution. In this work, electron beam nanopatterned polymer samples are fabricated directly on 3D zinc selenide prisms and used to experimentally evaluate the PTIR lateral resolution, sensitivity and linearity. It is shown that PTIR lateral resolution for chemical imaging is comparable to the lateral resolution obtained in the atomic force microscopy height images, up to the smallest feature measured (100 nm). Spectra and chemical maps are produced from the thinnest sample analyzed (40 nm). More importantly, experiments show for the first time that the PTIR signal increases linearly with thickness for samples up to ≈ 1 μm (linearity limit); a necessary requirement towards the use of the PTIR technique for quantitative chemical analysis at the nanoscale. Finally, the analysis of thicker samples provides the first evidence that the previously developed PTIR signal generation theory is correct. It is believed that the findings of this work will foster nanotechnology development in disparate applications by proving the basis for quantitative chemical analysis with nanoscale resolution.

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