Influence of Materials and Design Parameters on Zinc Oxide Surface Acoustic Devices

This thesis presents research into Zinc Oxide (ZnO) based resonators to include Width Extensional Mode (WEM), Length Extensional Mode (LEM), and Surface Acoustic Wave (SAW) devices. The design and operation of ZnO based SAW devices are investigated further to characterize design parameters and operating modes. Their design, fabrication, and results are discussed in detail. SAW device testing in conjunction with X-Ray Diffractometry (XRD) and Atomic Force Microscopy (AFM) are utilized to characterize ZnO and its deposition parameters on a variety of different substrates and interlayers, with different deposition temperatures and annealing parameters. These substrates include silicon, silicon oxide-on-silicon, and sapphire wafers with interlayers including titanium, tungsten, and silicon oxide. Fabrication methods are discussed to explain all processing steps associated with SAW and released contour mode resonators. The SAW devices in this research test different design parameters to establish better reflector design spacing for higher frequency Sezawa wave modes. The characterization and design of ZnO based SAW devices establishes the potential for prototyping high frequency SAW designs using standard lithography techniques. These devices are desired for space-based operations for use in GPS filters, signal processing, and sensing in satellites and space vehicles