SiO2 film overlays for temperature−stable surface acoustic wave devices

Abstract

Temperature−stable surface acoustic wave devices have been fabricated on YZ LiNbO3 and YZ LiTaO3 by the use of SiO2 film overlays. On LiNbO3, a temperature dependence similar to that of ST−cut quartz was obtained, but with a coupling constant k2 of at least 5.4%. On LiTaO3, a second−order temperature coefficient of delay that is 5 times smaller than and opposite in sign to that of ST quartz was observed. The coupling constant was measured to be approximately 1.6%.