Novolac resins may be prepared with or without a solvent present. We have found that solvent power greatly affects the properties of the finished resin and thus gives the resist chemist another variable with which to `fine-tune' resist properties. Using designed experiments, we investigated the effect of solvent power, as measured by Hansen's Solubility Parameters, of a number of solvents and solvent mixtures on the final properties of the novolac resin. We found that the relative molecular weight (RMW) and dissolution rate of a novolac resin can be varied by selection of a solvent or solvent mixture with the appropriate polarity and hydrogen- bonding characteristics. The solvent polarity and hydrogen-bonding characteristics may affect the stability of the cresol/formaldehyde transition state, thus causing the observed changes in RMW and dissolution rate.

Date Published: 15 September 1993
PDF: 11 pages
Proc. SPIE 1925, Advances in Resist Technology and Processing X, (15 September 1993); doi: 10.1117/12.154793

Published in SPIE Proceedings Vol. 1925:
Advances in Resist Technology and Processing X
William D. Hinsberg, Editor(s)