The roughnesses of five supersmooth dielectric films of Si3N4, TiO2, HfO2, Ta2O5, and Al2O3 prepared by an ion-beam-sputtering technique were measured with a commercial Talystep mechanical profiler and a sensitive Leica WYKO SPM30 scanning force microscope (SFM) to determine how much roughness the films added to the ~1-Å-rms roughness fused-silica substrates on which they were deposited. In all cases the increase in roughness for the three-quarter-wave optical thickness films was a small fraction of an angstrom. SFM measurements showed that the topography of the Ta2O5 and Al2O3 films was less random than that of the other film materials and the substrates.
© 1995 Optical Society of America
Original Manuscript: January 19, 1994
Revised Manuscript: June 1, 1994
Published: January 1, 1995
Jean M. Bennett, Mohammad M. Tehrani, Jay Jahanmir, John C. Podlesny, and Tami L. Balter, "Topographic measurements of supersmooth dielectric films made with a mechanical profiler and a scanning force microscope," Appl. Opt. 34, 209-212 (1995)