the difference in the variation 142 at the reference l 0 and the variation 142 at the distance 140 l i the curvature value is determined for a precise distance 142 for each zone 128 130 132 and 134 of the wafer subsequently the pressure variations are determined with each curvature value in accordance with formula 1 the method may be repeated during the cmp process to more precisely planarize the wafer as portions of a layer are removed the curvature of the wafer is affected if the measurement apparatus is included in the cmp machine the pressure profile may be adjusted as the curvature of the wafer changes the measurements are real time feed forward information that enhances post cmp uniformity in another embodiment several wafers from a batch of wafers may be measured to determine an average wafer warpage value at a specific stage of the processing for the wafers the average variation 142 for a precise distance 140 may be calculated from several wafers an average curvature value may be calculated and processed to determine the pressure differences to uniformly cmp the wafers the cmp machine 100 is programmed to apply the specific pressure differences to each wafer in that batch this can save the manufacturer time by avoiding determining the values l 0 and l i and pressure variations for each individual wafer the method provides an in situ cmp film profile controller that can be used to more uniformly cmp a wafer or plurality of wafers the method can improve the accuracy of endpoint detection techniques used by the manufacturer by enabling a more consistent polish by adjusting the down force applied to each zone of the wafer to accommodate.