Epitaxial growth and piezoelectric properties of lithium niobate thin films

Abstract

With the increasing volume of wireless communication globally, the demand for more sophisticated acoustic filter technologies to prevent signal interference has risen exponentially. A key component of acoustic filters is the piezoelectric film layer, and high-quality films are critical for high filter performance. This report studies the relevant parameters involved in the thin film deposition of a piezoelectric material, LiNbO3. The ideal conditions for the synthesis of a ceramic target are reported to include 3.5% of K2O in the solid-state synthesis process, while a sintering temperature of 900℃ yielded the highest ceramic density. This ceramic target was used to produce thin film samples, among which films deposited on LiTaO3 substrates yielded the highest uniformity. Ultimately, SAW devices were constructed onto the thin film samples and their resonance behavior was compared with SAW devices on bulk LiNbO3 crystals to observe their potential for applications in acoustic filter devices.