Journal of Xidian University ›› 2019, Vol. 46 ›› Issue (4): 144-149.doi: 10.19665/j.issn1001-2400.2019.04.020

Previous Articles     Next Articles

Design and verification of a film bulk acoustic resonator

SHEN Hongxia1,2,OU We12,3   

  1. 1.School of Microelectronics, Univ. of Chinese Academy of Sciences, Beijing 101400, China
    2.Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100020, China
    3.National Center for Advanced Packaging Co., LTD, Wuxi 214000, China
  • Received:2018-12-25 Online:2019-08-20 Published:2019-08-15

Abstract:

In order to simplify the design of the film thickness of the film bulk acoustic resonator, a design method for film bulk acoustic resonator film thickness is proposed. The simulation structure consists of the induced layer and the upper electrode-piezoelectric-electrode sandwich structure. The initial film of the film bulk acoustic resonator is designed by the optimal effective electromechanical coupling coefficient, and then the thickness of the induced layer and the corresponding frequency offset value are determined. The parallel resonant frequency is compensated with the frequency offset, and then the film thickness of the electrode and the piezoelectric are recalculated. Finally, the structure is simulated by COMSOL. When the parallel resonant frequency is 3.60 GHz, the frequency offset value of the 100 nm AlN is 0.20 GHz. The effective electromechanical coupling coefficient of the AlN is 5.907%. After frequency compensation, the series resonant frequency and parallel resonant frequency of the AlN are 3.48 GHz and 3.60 GHz, respectively. The design method is verified. The induced layer effectively optimizes the C-axis characteristics of the piezoelectric layer and reduces energy loss.

Key words: thin film bulk acoustic resonator, aluminum nitride, induced layers

CLC Number: 

  • TN713