We have etched submicron holes into SiO2, Ta2O5, and Nb2O5. The etching process has produced walls with low roughness, less than <30 nm, for Ta2O5 and Nb2O5, and <10 nm for SiO2, which compares well to the NiCr mask hole edge roughness of 5-10 nm. Three-inch wafers with real photonic-crystal structures have been etched. The problems associated with the high sublimation temperatures of TaF5 and NbF5 have been solved by increasing the substrate surface temperature to above 120 degreesC. However, for the narrowest holes, about 250 nm across, a pulsed electron-cyclotron-resonance method has had to be used in addition, in order to see an etching effect. (C) 2004 American Vacuum Society.