We have recently developed novel resist materials for micro-lithographic patterning. One is a hydroxystyrene derivative, which is a key compound for KrF excimer laser resists. We found that microwave-assisted decarboxylation of hydroxycinnamic acids smoothly proceeded under the presence of a catalytic amount of amine base, to afford hydroxystyrene derivatives in good yield.
The other is positive and negative-tone molecular resists utilizing the unique character of a furan ring. The synthesized compounds showed relatively high glass transition temperature and readily formed uniform amorphous films on a silicon wafer. The sensitivity as an EB resist of both positive and negative-tone resists was below 10 mu C/cm(2) and line and space patterns of 200 nm could be fabricated. The promising feature of the positive-tone resist is that no outgassed products from base matrixes are theoretically produced under the exposure and post-exposure bake procedure.