| abstract |
This invention relates to novel carboxylic acid derivatives represented by thenfollowing formula I and their synthesis:n n wherein, R 1 is an hydrogen atom, an alkyl group or an alkoxy group of 1 to 20ncarbon atoms in a linear, branched or cyclic form; R 2 is a carboxy group of 1 to 40ncarbon atoms in a linear, branched or cyclic form which is unsubstituted, or substitutedninto a hydroxy group, an ester group and an ether group. n The novel carboxylic acid derivatives are more easily decomposed by acid than t-butylnester compounds but are not dissolved in basic aqueous solution. According to thisninvention, carboxylic acid is under condensation with halogen compounds designed tonprepare a larger monomolecular compound compared to the conventional method.nFurther, the condensed site is easily decomposed by acid but is extremely insoluble bynbasic aqueous solution. The carboxylic acid derivatives in a photoresist compositionnfunction not only as a dissolution promoter in the exposed area due to formation of thencarboxylic aicd, thus enhancement of etching resistance and pattern profile in a resist. |