Two-Dimensional Phononic Crystal Slab Defect Mode Micromechanical Resonators

摘要

By creating line defects cavities in the structure of a phononic crystal (PC) made by etching a hexagonal (honeycomb) array of holes in a 15μm-thick slab of silicon, high-Q PC resonators are fabricated and tested using a complimentary-metal-oxide-semiconductor-compatible process. The radii of the holes are approximately 6.4μm and the spacing between nearest holes is 15μm. We show that the complete phononic band gap of the PC structure supports resonant modes with quality factors of more than 6000 at frequencies as high as 126MHz in the resonator structure. The very good confinement of acoustic energy is achieved by using only a few PC layers confining the cavity region. The calculated frequencies of resonance of the structure using finite element method are in a very good agreement with the experimental data. The performance of these PC resonator structures makes them excellent candidates for wireless communication and sensing applications.