In this paper, methods for decreasing mismeasurement by z-axis vibration in interferometry are proposed with the goal of improving measurement performance. The samples’ 3D height data is acquired by a phase compensation method which eliminates error components due to vibration. Also, the shape of the PS (Photo Spacer) is fitted to sigmoid function and remodeled by using its 3D height data and its CD (Critical Dimension) by subpixel level edge detection. The standard step height sample is measured at sinusoidal vibration of 2~20 Hz frequency and 50 nm amplitude to test improvement of measurement performance. Height repeatability (3σ) of a standard step height sample measurement is improved by more than 40% on average. Three types of PSs are also measured during vibration in the manufacturing process. Reliability of PS height and CD is within 1% in all cases. And repeatability of PS height and CD measurement is improved to a maximum of 65%. Stable measurement is possible during vibration in the manufacturing process by using a phase compensation method and a profile fitting method.
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