One method for measuring thin film thickness was proposed in this paper, which based on white light interference. One parallel flat crystal was used to be the standard glass, and put another glass on it, to form one air wedge between them. The reflectance spectrum of two beams interference was measured by one spectrometer. By fitting the reflectance spectrum, wave numbers corresponding to every peak can be found, then using two beam interference theory, the air gap thickness at light incident point can be fitted. By measuring the air gap thickness at different positions, the flatness of measured surface also can be analyzed.

Date Published: 28 February 2017
PDF: 7 pages
Proc. SPIE 10256, Second International Conference on Photonics and Optical Engineering, 102562D (28 February 2017); doi: 10.1117/12.2257412

Published in SPIE Proceedings Vol. 10256:
Second International Conference on Photonics and Optical Engineering
Chunmin Zhang; Anand Asundi, Editor(s)