Daesuk Kim et al 2002 Meas. Sci. Technol. 13 L1 doi:10.1088/0957-0233/13/7/101
Daesuk Kim1, Soohyun Kim1, Hong Jin Kong2, Yunwoo Lee3 and Yoon Keun Kwak1
Show affiliationsIn this communication, we describe a fast thickness profile measurement method for a transparent film, thinner than the white-light coherence length of 3-4 µm that is deposited on pattern structures. A visible acousto-optic tunable filter is employed for real-time wavelength scanning and the three-dimensional volumetric thin-film thickness profile information is obtained using a simple peak detection method in the spectral domain. The key idea is to divide the measurement into two states using a beam blocking mechanism to separately obtain the two unknowns of thickness and surface profile. Such separate measurements are required to compensate for the phase change effect caused by the multi-reflected beams from the thin film. The final thin-film surface profile information is measured by obtaining the number of peaks and phase deviations from the two separately scanned spectral intensity values.
42.79.Ci Filters, zone plates, and polarizers
42.30.-d Imaging and optical processing
42.79.Jq Acousto-optical devices
78.66.-w Optical properties of specific thin films
06.30.Bp Spatial dimensions (e.g., position, lengths, volume, angles, and displacements)
Instrumentation and measurement
Issue 7 (July 2002)
Received 28 March 2002, accepted for publication 9 May 2002
Published 31 May 2002
Daesuk Kim et al 2002 Meas. Sci. Technol. 13 L1
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