Abstract: A method for obtaining texture measurements of a highly-polished surface (110) uses a directed-energy light source (124) to perform the steps of scattering the directed-energy light from a plurality of known texture surfaces. The known texture surfaces have equivalent surface area and dimensions to those of the highly-polished surface (110). A next step is to measure (102 and 130) the scattered light from the directed-energy light source (124) to establish a threshold energy level measurement (48, 50, or 52) above which the measured scattered light varies according to differences in texture among the plurality of known texture surfaces. From variations in the measured scattered light a texture-light relationship (Equation 1) is established that expresses expected changes in measured scattered light according to changes in texture in the plurality of known texture surfaces. Scattered light from the highly-polished surface (110) is then measured.

Abstract: The invention is to a polishing pad 14 that has a polishing surface 19 in which portions 17 and 18 of the polishing surface 19 have been removed. The removed areas 17 and 18 are annular rings adjacent an outer 15 and inner 16 edges of the polishing pad 14. The non-polishing surfaces 18 and 19 taper 17a and 18a downward from the polishing surface 19.