PHOTORESIST MONOMER AND ITS PRODUCTION, PHOTORESIST COPOLYMER, PHOTORESIST COMPOSITION, FORMATION OF PHOTORESIST PATTERN AND SEMICONDUCTOR ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide a new compound that bears one or more carboxylic acid an butyl groups and can readily produce a large amount of photoresist resins for electron beams and X-rays in low costs. SOLUTION: This new compound is represented by formula I (R1 and R2 are each H, t-butyl; X is hydrogen, hydroxy, oxygen; n is 1-3), typically 5- norbornene-2-carbony-di-t-butyl malonate. The compound of formula I is prepared by allowing a compound of formula II (R3 is a halogen as chlorine, bromone, iodine or the like or H) to react with a malonic salt of formula III (R4 and R5 are each t-butyl or sodium ion) in a solvent, acidifying the remaining solution after the solvent distillation from the reaction mixture and separating and purifying the organic layer. An example of malonic acid salt of formula III is the sodium salt of di-t-butyl malonate of formula IV.