Optical measurement of silicon membrane and beam thickness using a reflectance spectrometer

An optical technique for measuring the thickness of silicon membranes and beams such as those used in micromechanical devices is presented. The measurement, based on reflectance spectrometry, is rapid and nondestructive. The reflectance-spectrometry technique can be used to measure silicon membrane thickness in the range from 0.1 to 5 mu m.<
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