Process for preparing stable photoresist compositions

摘要

A composition of matter consisting of a stable solution containing a polymer derived from a solution of a polymer containing trace metals, the derived method comprising the steps of: (a) providing a polymer solution containing a polymer, a first solvent and trace metals; (b) passing said polymer solution through an acidic cation ion exchange material to remove said trace metals therefrom and thereby forming a polymer solution containing free acid radicals; (c) precipitating said polymer from said polymer solution of step b by contacting with a second solvent wherein the polymer is substantially insoluble therein; (d) filtering said solution and said second solvent to thereby form a solid polymer cake; and (e) contacting said cake from step d with sufficient quantities of additional said second solvent in order to remove free acid radicals there from.