Moderate temperature sol–gel deposition of magnesium fluoride films for optical UV‐applications:A study on homogeneity using spectroscopic ellipsometry

Abstract Thin films of MgF₂ have been deposited on silicon wafers in optical quality with a novel sol–gel deposition process at temperatures as low as 100 °C. The properties of the fluoride layers are compared to bulk MgF₂ with respect to the optical constants. By employing spectroscopic mapping ellipsometry, the uniformity of the thickness of fluoride layers is confirmed to be within acceptable limits for optical applications. The optical constants are close to the bulk data. High‐quality low‐index films of suitable and homogeneous thickness have already been produced on a laboratory scale. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)