METHOD FOR CONTROLLING POLISHING TIME OF WAFER BY USING ALGORITHM OF SAMPLE SKIP METHOD AND METHOD FOR POLISHING WAFER USING THE SAME

摘要

PURPOSE: A method for controlling polishing time of a wafer by using an algorithm of a sample skip method is provided to effectively reduce a variation of an elimination rate occurring between heads, by forming a plurality of heads so that a variation scope between lots is minimized. CONSTITUTION: A chemical mechanical polishing(CMP) process is performed regarding a plurality of wafers constituting the n-th lot among a plurality of lots for an interval of delta t(n) so that delta ToxP(n), the eliminated quantity of a polishing layer is obtained. RRb(n), the elimination rate of the polishing layer regarding a blanket wafer is obtained from delta ToxP(n). The CMP time, delta(n+1) regarding a wafer in the (n+1)-th lot is obtained from delta ToxT(n+1), the target quantity of the polishing layer eliminated from the wafer in the (n+1)-th lot while using a relational expression, delta t(n+1)=(delta ToxT(n+1)+A)/RRb(n) where A is a constant.