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Optical Engineering • Open Access

In situ measurement of MEMS topography based on phase-shifting interferometry
Author(s): Xi Chen; Hua Rong

Paper Abstract

Currently, phase-shifting interferometry is widely used in MEMS (micro-electro-mechanical system) microsurface topography measurements, and an expensive and high-precision piezoelectric transducer (PZT) is often necessary to realize phase-shift operation. Because of the feature of a MEMS structure which always has a flat substrate, a practical algorithm to calculate phase shifts by fast Fourier transformation (FFT) from gathered interference fringes of the substrate is presented, then microsurface topography can be reconstructed according to the obtained phase shifts. By means of the presented algorithm, an expensive and high-precision PZT is unnecessary and the phase-shift operation can even be carried out by rotating the fine focus adjustment knob. The accuracy and feasibility of the method have been verified by experiments. Experiments indicated that the presented method can satisfy the needs of in situ MEMS topography measurements and is very simple.

Paper Details

Date Published: 5 February 2015
PDF: 8 pages
Opt. Eng. 54(2) 024103 doi: 10.1117/1.OE.54.2.024103
Published in: Optical Engineering Volume 54, Issue 2
Show Author Affiliations
Xi Chen, Nanjing Normal Univ. (China)
Hua Rong, Nanjing Normal Univ. (China)

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