A method includes forming multiple trenches in a first wafer, forming a sensor structure on a first surface of a second wafer, and bonding the first wafer and the second wafer. The method also includes etching a second surface of the second wafer to form a sensor diaphragm in the second wafer. The method further includes removing a portion of the first wafer by cutting the first wafer in multiple areas of the first wafer associated with the trenches. A sensor includes a substrate and a surface acoustic wave (SAW) resonator on a first surface of the substrate. The sensor also includes a bonding pad electrically coupled to the SAW resonator and a notch formed in a second surface of the substrate. The sensor further includes a cover separated from the first surface of the substrate by a spacer. The SAW resonator is located between the cover and the substrate.