POLYSULFONES AS X-RAY RESISTS

The microlithographic process essential in the fabrication of microdevices uses high-energy radiation to transfer a pattern onto a thin film of polymer resist. Pattern transfer occurs by modifying the properties (solubility or volatility) of the polymer film exposed to radiation. Poly(olefin sulfones) exhibit a high sensitivity to x-rays which is a desirable property for polymer resists used in the microlithographic process. The potential utility of these new resins prompted a study of the mechanism of degradation promoted by x-ray radiation. In this study the effect of x-ray radiation on polysulfones with varied chemical structures was analyzed using x-ray absorption near-edge structure (XANES) spectroscopy and in-situ mass spectroscopy (MS). Interesting differences in the mode of degradation of certain poly(olefin sulfones) was observed. The results provide important groundwork for further studies of polysulfones as x-ray resists.