A surface acoustic wave (SAW) resonator includes a piezoelectric layer disposed over a substrate, and a plurality of electrodes disposed over the first surface of the piezoelectric layer. A layer is disposed between the substrate and the piezoelectric layer. A silicon layer disposed between a first surface of the layer and a second surface of the piezoelectric layer. A first surface of the silicon layer has a smoothness sufficient to foster atomic bonding between the first surface of the silicon layer and the second surface of the piezoelectric layer.