Influence of polymer properties on airborne chemical contamination of chemically amplified resists

摘要

We describe here an extensive study of the relation between polymer structure and rates of NMP uptake for a set of polymer films with a very broad range of properties. NMP labeled using radioactive $+14$/C was introduced at a concentration of 12 ppb into a stream of purified air. The film of interest was then immersed in the airstream for a predetermined time under controlled conditions. The radionuclide serves as a tag which allows precise quantitation of NMP absorbed by the polymer film. NMP uptake rates measured using this method are shown to correlate with polymer physical properties in a straightforward manner. The observed trends are in accord with those expected on the basis of the solution diffusion model of polymer permeation. These data provide a basis for the rational design of polymers for chemically amplified resists which are insensitive to airborne contaminants.