Spectrally resolved white-light interferometry for 3D inspection of a thin-film layer structure.
We describe an improved scheme of spectrally resolved white-light interferometry, which provides 3D visual inspection of a thin-film layer structure with nanometer level resolutions. Compared to the authors' previous method [Appl. Phys. Lett.91, 091903 (2007)APPLAB0003-695110.1063/1.2776015], 3D tomographic information of thin films can be obtained by decoupling the film thickness and top surface profile, which is embodied by inducing spectral carrier frequency to the reference arm and applying a low-pass filter to the interferogram instead of two troublesome measurement steps of activating and deactivating a mechanical shutter. We test and verify our proposed method by measuring a patterned thin-film layer structure as well as standard specimens of thin films with various thicknesses.
Ghim
Young-Sik
YS
Department of Physics and Optical Science, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223, USA. yghim@uncc.edu
Kim
Seung-Woo
SW