Defect Detection on Ultra-Flat Wafers (Magic Mirror™) Full Wafer Submicron Defect Detection Systems. The concept is a powerful topographic tool for the characterization of the morphology of glass and mirror-like surfaces, such as semiconductor wafers. The sensitivity of the method is a 0.4 μm height difference over a 10 mm distance and 50 nm over a 0.5 mm distance. Makyoh topography has proven its power, for example in detecting flaws induced by wafer slicing, polishing, lapping, and defects in directly bonded Si wafers.