| Popis: |
A new synthesis pathway for 4- and 2-hydroxymethylcarbinol (4- and 2-HPMC) has made a new class of highly branched polymers readily available. The polymers, which are isomers of polyhydroxystyrene, show unexpected dissolution behavior in aqueous bases which differs from the solubility characteristics seen for the linear polymers obtained by free-radical polymerization. This behavior is traced back to the influence of the changing bond types in the co-polymerization series on the kinetic parameters. With respect to lithography, the absorption of the polymers is too high to make them attractive as DUV resist materials. Although their bond structure shows all bond types that also exist in novolaks, the HPMC polymers are found to be more PHS-like than novolak-like in their performance with DNQ sensitizers. However, they are compatible with DNQ/novolak resists, and can be used in resin blends with novolaks without phase separation. |
