In this paper a method is described which enables us to perform a complete optical analysis of non-absorbing columnar thin films. the columnar refractive index, packing density and thickness of these films can be determined by means of an interpretation of the spectral dependences of the reflectance of the films. These dependences must be measured in suitable ambients. The method is demonstrated using LiF films deposited onto single-crystal silicon. The reflectance of LiF films was measured in air, toluene and acetone. Using the reported method it is found that the columnar refractive indices of LiF films are identical with those of bulk LiF. Furthermore, the packing densities of LiF films reach those expected. In this paper we also present the surprising fact that a small amount of water is contained in the pores of LiF films, at least at several tens of minutes after deposition. © 1980.
Ohlídal, I., & Navrátil, K. (1980). Determination of the optical parameters and packing density of non-absorbing columnar thin films by means of immersion reflectometry: Application to LiF thin films. Thin Solid Films, 74(1), 51–58. https://doi.org/10.1016/0040-6090(80)90438-1