Laser interferometry for the determination of thickness distributions of low absorbing films and their spatial and thickness resolutions

Abstract

New laser interferometry has been developed, based on the principle that a 2-D fringe pattern can be produced by interference of spatially coherent light beams. To avoid the effect of reflection from the back surface of the substrate, the Brewster angle of incidence is adopted; to suppress the effect of diffraction, a lens or a lens system is used. This laser interferometry is an efficient nondestructive technique for the determination of thickness distributions or uniformities of low absorbing films on transparent substrates over a large area without involving laborious computations. The limitation of spatial resolution, thickness resolution, and visibility of fringes is fully analyzed.

© 1982 Optical Society of America

Determination of 2-D thickness distributions of low absorbing thin films by new laser interferometry

Teruhito Mishima and Kwan C. Kao
Appl. Opt. 21(16) 2894-2896 (1982)

Determination of spatial distributions of thickness and optical constants of thin films by a new optical technique

Teruhito Mishima and Kwan C. Kao
Appl. Opt. 20(21) 3719-3722 (1981)

Determination of the optical constants and thickness of thin films on slightly absorbing substrates

Rusli and G. A. J. Amaratunga
Appl. Opt. 34(34) 7914-7924 (1995)

Spatially resolved thickness determination of rough thin films by reflectometry with polychromatic light

Frank Hergert
Appl. Opt. 56(9) D79-D83 (2017)

Measurements of the thickness distribution of thin films with a slit-beam-profile reflectometer

De-Kui Qing, Ichirou Yamaguchi, Takayuki Okamoto, and Mari Yamamoto
Opt. Lett. 25(12) 914-916 (2000)