Comparison of surface roughness measurements by stylus profiler, AFM and non-contact optical profiler

Surface roughness measurements were performed on a glass-ceramic disk substrate by stylus profiler (SP), atomic force microscope (AFM) and non-contact optical profiler (NOP). Results of surface measurements are presented and the differences between SP, AFM and NOP roughness measurements are discussed. The effects of stylus size, scan size and sampling interval on roughness parameters are investigated. The methodology of choosing the scan size and sampling interval is suggested. AFM is concluded to be the most suitable surface measuring instrument for roughness measurement on the glass-ceramic substrate. If SP is used to make the measurement, the tip radius should be in the order of 0.2 mu m. However, localized damage to the test surface may occur owing to high contact stress. NOP using an objective magnification of 40 or lower is not recommended because the glass-ceramic substrate contains submicron roughness.