The Resonance Characteristics of Solidly Mounted Resonators with 1/4 and 1/2 λ Mode Configurations

• Main Authors: Sin-Ren Li, 李新仁
• Other Authors: Ying-Chung Chen
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/g3d3n4

碩士 === 國立中山大學 === 電機工程學系研究所 === 96 === In this thesis, we emphasized on fabrication and anlysis of 1/4 and 1/2 λ mode solidly mounted resonators. First, the reactive RF magnetron sputter used to deposit the highly c-axis-oriented aluminum nitride (AlN) piezoelectric films under different parameters. The various c-axis tilt angle also used it by altering the distance between substrate and target to investigate the characteristics. To accomplish the two modes of different pairs of Bragg reflector, the RF/DC sputter system is adopted alternating layers of quarter-wavelength Mo and SiO2 thin films by different sequence. Finally, depositing the highly c-axis-oriented AlN on reflectors to complete the 1/4 and 1/2 λ mode SMR. The AlN thin film achieve a very low roughness of 1.783nm under AFM measurement, the FWHM of XRD(002) peak is 3.507°and SEM images also exhibit a highly oriented c-axis structure. The optimum frequency responses of 1/2 λ mode SMR is obtained with return loss of -57.23dB at 4 pairs reflectors,which for 1/4 λ mode SMR is -30.68dB at 3 pairs. The maximum electromechanical coupling coefficient (Kt2) of 1/2 λ mode SMR is 7.88%, but the quality factor (Q) of 1/4 λ mode SMR is 4231.29.