Acoustic filters based on thin single crystal LiNbO3 films: Status and prospects

Lithium niobate has been extensively used in the Surface Acoustic Wave (SAW) industry for its excellent piezoelectric properties. In the last twelve years, the interest has been raised towards making this material available in the thin film form for SAW or Bulk Acoustic Wave (BAW) applications, and even for Lamb wave devices. This paper reviews both deposition or thin film transfer techniques to obtain lithium niobate thin films. It also gives a brief overview of the applications of these thin films. Finally, we open new perspectives for this technology with the emerging field of tunable acoustic filters, which need extremely large piezoelectric properties to demonstrate satisfying performance.