Patent ID: 6154280
Filing Date: 2000-11-28
Classification: G01B

Abstract:
A system for measuring microroughness of a surface of a substrate, comprising:means for generating a first beam of electromagnetic radiation and a second beam of electromagnetic radiation, the first and second beams being substantially parallel and spaced apart from each other so that the first and second beams are substantially non-overlapping;means for focusing the first and second beams onto the substrate so that the beams impinge upon the surface of the substrate:means for moving the beams back and forth across a selected area of the surface of the substrate to generate an oscillatory signal as the beam are scattered by the surface of the substrate, the surface having a microroughness with a plurality of scattering points, each scattering point causing scattering of both beams and the oscillatory signal corresponding to the microroughness of the selected area of the substrate;means for detecting the oscillatory signal corresponding to the scattering of the first and second beams; andmeans, responsive to the detecting means, for determining the microroughness value of the selected area of the substrate based on the scattering of both beams.