METHOD FOR REFINING BASE POLYMER OF RESIST

摘要

PROBLEM TO BE SOLVED: To provide a method for refining the base polymer of a resist by efficiently diminishing a metal impurity in the base polymer. SOLUTION: In the method for refining the base polymer of a resist, a water- soluble compound having complex forming ability is added to the base polymer or a solution of the base polymer in a non-polar organic solvent or a mixed solvent comprising non-polar and polar organic solvents by an amount not less than the equivalent of a metal impurity in the base polymer, reaction is completed and the base polymer is washed with pure water to diminish the metal impurity in the base polymer.