Optical non-contact micrometer thickness measurement system for silica thick films

In this paper, a novel optical approach is proposed and demonstrated for the non-contact measurement for the thickness of silica thick films. This approach is based on the principal of an optical based displacement sensor. The calibration curve for the measurement of the thickness of an unknown sample is obtained using four sample with known thicknesses of 6.90, 10.23, 19.69 and 25.47 μm respectively. As compared to a prism coupler, which is assumed to provide the most precise measurement of thick film thicknesses, the proposed system has an error of approximately 8%. The proposed method is able to provide a simple, low cost and time saving approach in measuring thick films thicknesses during fabrication.

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