Investigation on the Optimized Design of Alternate-Hole-Defect for 2-D Phononic Crystal Based Silicon Microresonators

• Main Author: 潘睿郁
• Other Authors: 蕭輔力
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/12484330424742730407

碩士 === 國立彰化師範大學 === 光電科技研究所 === 101 === This paper shows the design, fabrication and characterization of the Bloch-mode micromechanical resonators made by creating alternate defects to form a resonant cavity on a two-dimensional （2-D） silicon phononic crystal （PnC） slab of square lattice. The length of the resonant cavity （L） and the central-hole radius （r’） are varied to optimize the performance of the resonators. CMOS-compatible aluminium nitride （AlN） is used as the piezoelectric material of the interdigital transducer （IDT） to launch and detect acoustic waves. The extent of energy confinement within the cavity, as shown by the simulated displacement profiles of the resonators, agrees with the measured Q factors. We also quantitatively analysed the band structure of the proposed resonators and found that the Q factors are generally in an inverse relationship with the standard deviation of the band, due to the slow sound effect brought by flat bands which reduces the energy loss along the lateral direction （Y direction） and enhances the Q factor.