Nano step height measurement using an optical method

This paper presents two optical methods for measuring nano step height standards and discusses the deviations in the measurements in detail. A white light interference (WLI) microscope and spinning disk confocal (SDCF) microscope were used in the experiments. The effect of illumination intensity and the standard's surface reflectivity were studied and analyzed. The surface properties of the step height standard were ameliorated using secondary coating technology. The experimental results demonstrated that the secondary coating technology effectively improved the measurement accuracy of the SDCF microscope. The WLI microscope measured accurately both before and after a secondary coating was applied.