Method and apparatus for predicting process characteristics of polyurethane pads

摘要

A measurement of polyurethane pad characteristics is used to predict performance characteristics of polyurethane pads used for chemical mechanical planarization (CMP) of semiconductor wafers, and to adjust process parameters for manufacturing polyurethane pads. In-situ fluorescence measurements of a pad that has been exposed to a high pH and high temperature environment are performed. The fluorescence characteristics of the pad are used to predict the rate of planarization of a wafer. A portion of one pad from a manufacturing lot is soaked in an organic solvent which causes the portion to swell. The relative increase in size is indicative of the performance characteristics of pads within the manufacturing lot. Statistical Process Control methods are used to optimize the CMP pad manufacturing process. Predicted pad characteristics are available for each pad.