β Scribed by Mark G. Cupta; Paul Jayachandran Joseph; Paul A. Kohl
No coin nor oath required. For personal study only.
The photoβactivated, acid catalyzed decomposition of polycarbonate was investigated in this study. The impact of the chemical and physical properties of the photoacid generators (PAG) and the ambient atmosphere effect on polycarbonate decomposition were discussed. The photoβpatterns resulted from the photoacid catalyzed decomposition of a polycarbonate can be used as a sacrificial placeholder for fabrication of microelectromechanical and microfluidic devices. The effects of acid strength, vapor pressure of the acid, PAG activation process, and ambient conditions (temperature, moisture, and oxygen concentrations) on polymer film decomposition were studied. Several superacids (e.g. triflic and nonaflic based PAGs) were not suitable for decomposition of the polycarbonate because of their high vapor pressures resulting in the high volatility properties. From the decomposition experiments it was found that the nonfluorinated sulfonic acid based PAGs do not posses the superacidity needed for decomposition. Perfluorinated methide and a tetrakis (pentafluoropheyl)borate PAG were effective in the decomposition of polycarbonate films. The combination of two PAGs, one which generates high vapor pressure acid (thus, highly volatile) and the other with a lower vapor pressure acid (thus, less volatile) showed very low residue levels. This is because of the volatility of the generated high vapor pressure acid (usually remaining acid in the film was the cause of the residue left behind) and the remaining nonvolatile low vapor pressure acid was sufficient to decompose the polycarbonate that was not decomposed by the generated high volatile acid. Β© 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
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