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Author Lippert, T. ♦ Koskelo, A. ♦ Stoutland, P. O.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword MATERIALS SCIENCE ♦ POLYMERS ♦ INFRARED SPECTRA ♦ ACRYLATES ♦ ORGANIC ACIDS ♦ DECOMPOSITION ♦ PHOTOCHEMICAL REACTIONS ♦ STRUCTURAL CHEMICAL ANALYSIS
Abstract As part of a program to develop diagnostics for laser-driven reaction in polymer matrices, we have investigated the photoinduced decomposition of 5-diazo-2,2-dimethyl-1,3-dioxane-4,6-dione (5-diazo Meldrum`s acid, DM) in a PMMA matrix. This particular diazoketone is sensitive to deep UV (200-260nm), making it suitable for high-resolution lithographic applications. It has historically been difficult to study the chemistry of such resists as many of the intermediates are short-lived and absorb only in the UV. Recent advances in ultrafast infrared spectroscopy, however, now allow us to directly examine the initial steps occurring in UV photoresists with infrared spectroscopy. Herein, we describe the first room temperature observation of intermediates in the photochemistry of DM with utlrafast infrared spectroscopy. In summary, these experiments have provided the first example of how ultrafast infrared spectroscopy may be used to examine laser-driven reactions in polymeric matrices. We have determined that the photoinduced Wolff rearrangement of DM in a PMMA matrix is complete within 20 ps. The IR band assignable to the ketene is centered at 2161 cm{sup -1} and has a width of 29 cm{sup -1}. The rapid formation of the ketene is a key element of the high quantum yield of carboxylic acid formation and a key element as well for the use of DM as an ablation sensitizer. 22 refs., 3 figs.
ISSN 00027863
Educational Use Research
Learning Resource Type Article
Publisher Date 1996-02-14
Publisher Place United States
Journal Journal of the American Chemical Society
Volume Number 118
Issue Number 6


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