ROLE OF RESIDUAL CASTING SOLVENT IN DETERMINING THE LITHOGRAPHIC AND DISSOLUTION BEHAVIOR OF POLY(METHYLMETHACRYLATE)

The effect of the pre-exposure bake and the choice of casting solvent on the sensitivity and contrast of poly (methylmethacrylate) (PMMA) has been documented to an extent not previously reported in the literature. Films baked at temperatures below Tg(the temperature which marks the onset of long-range, coordinated molecular motion), exhibited improved sensitivity and poorer contrast when compared to those baked above Tg. Dissolution rates and relative concentrations of casting solvents remaining in the films were also measured. Cross-correlation of these results with energy deposition calculations indicate that the pre-bake temperature more strongly correlates with the observed improvement in sensitivity than the presence of residual casting solvent. © 1995, American Vacuum Society. All rights reserved.