Accuracy Improvements in LPC Measurements for CMP Slurries

Abstract

We have examined the Large Particle Count (LPC) analytical method to see whether there are opportunities to improve both the accuracy and precision in hope of improving the utility of the LPC measurement. We have identified weaknesses in the current method that limit both its accuracy and its precision, and which can introduce count errors in excess of a factor of 10. We propose modifications to the current method which result in both accuracy and precision improvements. We recommend these improvements as absolutely necessary for any experiments designed to test the correlation between LPC and defectivity.