Surface evaluation of LiNbO₃ and LiTaO₃ crystals etched using fluorine system gas plasma reactive ion etching

Abstract

Abstract The etching characteristics of LiNbO 3 and LiTaO 3 single crystals have been investigated by performing plasma reactive ion etching (RIE) with CF 4 /Ar, CF 4 /H 2 , and CF 2 /Ar/H 2 gas mixtures. The etched surface was evaluated by atomic force microscopy and X‐ray diffraction. The in situ surface temperature of the sample was measured during RIE. F atoms exist in the contamination layer on the surface etched using mixtures of CF 4 , Ar, and H 2 gases. The etch rate was dependent on the crystal orientation. The etch rate of LiTaO 3 was less than that of LiNbO 3 . © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 149(2): 18–24, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10365