Apparatus and method for measuring thickness and profile of transparent thin film using white-light interferometer

Abstract

Disclosed herein is an apparatus and method for measuring the thickness and profile of a transparent thin film using a white-light interferometer. The apparatus and method separate coherent light according to frequency, obtain a first interference pattern at each frequency, separate composite coherent light according to frequency, and obtain a second interference pattern at each frequency. Further, the apparatus and method obtain a phase, generated by the thickness of the thin film, from the first interference pattern, and acquire only information about the thickness of the thin film. Further, the apparatus and method obtain a phase from the second interference pattern, and acquires information about the profile of the thin film, including information about the thickness of the thin film. Further, by using the thin film thickness information, information about the profile of the thin film is acquired from the thin film profile information including the thin film thickness information. Therefore, the present invention can process a measurement region with respect to a single point or single line through real-time measurement and a single measurement without requiring a separate driving device, and is resistant to external vibration.