散乱理論を用いた微小傷の測定評価に関する研究(第2報)

傷の深さと幅の定量的評価について

抄録

In this paper, the optical measuring method of fine scratches on mirror surfaces, such as the magnetic memory disk and the block gauge is investigated. The theoretical background of this method is based on Beckmann's Kirchhoff Approximation which is the theory of scattering of electromagnetic waves. Emphasis is on quantitative measuring method of fine scratches by the non-contact method. The results obtained are summarized as follows : First, the profile of fine scratch can be approximated to the triangle scratch, because experimental results from the various profiles of scratches are in close agreement with those in computer simulations for triangle scratches of the same depth and width. Secondly, typical factors related to size of scratch are found by the zero-and first order scattering intensities and the scattering angle, which are obtained from scattering intensity distributions. And then the depth and width of a scratch is simultaneously estimated by them. Finally, the range to be measured by this method is from 0.05 to 0.4 μm deep, from 10 to 80 μm wide for the scratches resulting spontaneously on block gauge and the scratches fabricated by diamond cutting tools.