Multilayer piezoelectric substrate device with polycrystalline substrate

A multilayer piezoelectric substrate for a surface acoustic wave resonator, the multilayer piezoelectric substrate comprising:

• a carrier substrate having an upper surface;
• a high acoustic velocity dielectric layer having a lower surface disposed on the upper surface of the carrier substrate and an upper surface to reflect acoustic energy generated by the surface acoustic wave resonator away from the carrier substrate, the high acoustic velocity dielectric layer comprising silicon nitride and silicon dioxide;
• a low acoustic velocity dielectric layer having a lower surface disposed on the upper surface of the high acoustic velocity dielectric layer and an upper surface, the low acoustic velocity dielectric layer exhibiting a lower acoustic velocity than an acoustic velocity of the high acoustic velocity dielectric layer;
• and
• a layer of lithium tantalate having a lower surface disposed on the upper surface of the low acoustic velocity dielectric layer.