Surface morphology and removal rates for dry- and wet-etched novel resonator materials - Part II. La3Ga5.5Nb0.5O14

The wet and dry etching behavior of La3Ga5.5Nb0.5O14 is reported. The ultim ate application for this material is as crystal resonators whose operating frequency is inversely proportional to sample thickness. Reaction-limited w et etching in HCl or HF at greater than or equal to 25 degrees C, or HNO3 a t greater than or equal to 60 degrees C produced removal rates up to 9500 A ngstrom . min(-1) (HCl at 65 degrees C), with surface root-mean-square (RMS ) roughnesses about a factor of two higher than on an unetched control samp le. Dry etching in Cl-2-based plasmas produced removal rates up to 950 Angs trom . min(-1), with surfaces RMS values also about a factor of two higher than on control samples. Significant surface roughening occurred during dry etching when higher ion fluxes were used. (C) 2000 Elsevier Science B.V, A ll rights reserved.