HEAD ASSEMBLY FOR EDGE POLISHING APPARATUS OF WAFER

摘要

PURPOSE: A head assembly for a wafer polishing apparatus is provided to prevent defects of the polished edge of a wafer by transferring adhesion pressure evenly over the entire area of the wafer. CONSTITUTION: A head assembly for a wafer polishing apparatus comprises an empty head(10), an expandable member(20), a back film(30), and outer and inner retainer rings(40,50). An air hole(13) is formed in one end of the head. The expandable member is airtightly coupled to the open end of the head. The back film contacts a wafer(60) on a polishing pad(70) by the expansion of the expandable member. The outer retainer ring is installed in the back film corresponding to the rim of the head so as to contact the polishing pad. The inner retainer ring is arranged concentrically with the outer retainer ring so as to hold the wafer.