Interferometric Characterization of Subwavelength Lamellar Gratings

Philippe Lalanne (1) , Pierre Pichon (2) , Pierre Chavel (2) , Edmond Cambril (3) , Huguette Launois (3)

1 Laboratoire Charles Fabry de l'Institut d'Optique / Naphel
2 Laboratoire Charles Fabry de l'Institut d'Optique / Scop
3 L2M - Laboratoire de Microstructures et de Microélectronique

We propose a new, to our knowledge, method for determining the two main critical parameters of periodic one-dimensional lamellar structures, namely, linewidths and etched depths. The method is simple and requires only two measurements for the phase of the zero-transmitted order under two orthogonal polarizations. It is inspired by the analogy between subwavelength gratings and anisotropic homogeneous thin films. The method is tested with experimental data obtained with a Mach-Zehnder interferometer. Etched depths and linewidths derived from the interferograms and electromagnetic theory are compared with scanning-electron-microscope observations.

Domains: Optics [physics.optics]

Philippe Lalanne, Pierre Pichon, Pierre Chavel, Edmond Cambril, Huguette Launois. Interferometric Characterization of Subwavelength Lamellar Gratings. Applied optics, 1999, 38 (23), pp.4980-4984. ⟨10.1364/AO.38.004980⟩. ⟨hal-00877945⟩