Photogenerated Base in Polymer Imaging and Curing: Novel Imaging Material Based on an Amine-Catalyzed Isomerization Process.

Abstract : The use of base photogenerated in situ within a polymer coating affords attractive possibilities for the imaging or curing or reactive polymeric materials. In the case of resists. photogenerated base may provide access to materials that are more resistant to airborne contaminants than the chemically amplified resists currently available commercially today. We have designed a family of novel copolymers containing benzisoxazole pendant groups that rearrange to cyanophenols in the presence of a catalytic amount of amine. The rearrangement also occurs thermally at elevated temperatures and may be easily followed by DSC. Films of the benzisoxazole-substituted copolymers containing a small amount of photogenerated base may be imaged to afford positive-tone images of the mask as the rearranged polymer is more soluble in aqueous base than the starting copolymer. At the present time the sensitivity of this resist is relatively low (ca. 100mJ/sq cm), but this may be optimized.