Wafer Curvature and Flatness Measurements Using The Magicmirror (Makyoh) Method

Abstract

ABSTRACTA new method is presented for the measurement of the radii of curvature R of semiconductor wafers using the magic-mirror (Makyoh) technique. A flat mirror is placed beneath the sample, thus a second, “contour” image of the sample is formed beside the Makyoh image. From the ratio of the two image sizes, R can be determined using a set of reference curved mirrors. Model calculations show good agreement with the results. Other examples of assessing of the flatness of semiconductor samples are presented as well.