The disclosure provides a structure for a microelectromechanical system (MEMS)-based resonator device. The structure for the MEMS-based resonator device includes at least one resonator unit. The at least one resonator unit comprises a substrate having a trench therein. A pair of first electrodes is disposed on a pair of sidewalls of the trench. A piezoelectric material fills the trench, covering the pair of first electrodes. A second electrode is embedded in the piezoelectric material, separated from the pair of first electrodes by the piezoelectric material. The second electrode disposed in the trench is parallel to the pair of first electrodes.