Materials and device modeling of zinc oxide/diamond/silicon structures for surface acoustic wave devices

Surface acoustic wave (SAW) devices are characterized by three main parameters which are SAW velocity, electro-mechanical coupling coefficient and temperature dependence which are determined by material constants. Bulk piezoelectric materials have usually been used for SAW devices up until the present time. Layered structures are also being studied for SAW devices because these parameters can be modified, however, they have different characteristics than bulk SAW substrates. This dissertation is related to SAW devices using ZnO/Diamond/Si layered structures because of its high SAW velocity.; Several SAW device models are presented for bulk SAW substrates and SAW device applications are developed using these modeling methods. Since layered structures have different characteristics, conventional SAW device modeling and design methods can not be used for layered structures.; This dissertation first presents the differences between the characteristics of bulk and layered structures which have not been previously discussed. Based on these differences, three types of SAW models are developed which are the delta function model, equivalent circuit model and impulse response model for layered structures are discussed in this dissertation.; Three types of SAW device applications, unapodized transducers, interdigitated interdigital transducers (IIDT) and SAW resonators, are designed using the presented new models and compared with bulk SAW devices.; SAW electrode design techniques for apodized transducers have usually used the finite impulse response (FIR) method. This technique is very useful for bulk SAW substrates. For layered structures, this technique can not be used directly. This dissertation gives a new SAW electrode design method for layered structures instead of the conventional FIR method. Two types of design techniques are evaluated for layered structures using this new method. The method, which includes the characteristics of the layered structures and bulk substrates, will also be given in this dissertation. Two types of SAW devices are fabricated and measured to verify the theoretical approach.