Measurement and Characterization of Surface Roughness of Polishing PAD

Surface roughness of polishing pad is a key factor determines the material removal process in chemical mechanical polishing (CMP). However, little research has been done about the impact of processing and measuring methods on the surface roughness results. This work focused on the measurement and characterization of polishing pad surface roughness. Polishing pad surfaces treated by different methods were measured and compared. In addition, both confocal laser scanning microscope (CLSM) and white light scanning interferometer (WLSI) were used to analyze the roughness parameters of the samples. The results indicate that the limitation of lateral resolution and the inability in detecting objects with steep angles are the main error of the WLSI when measuring the polishing pad surface. This study may contribute to measuring and characterizing the surface roughness of polishing pad correctly.