Title :
P1J-7 Solidly Mounted Resonator (SMR) FEM-BEM Simulation
Author :
Ekeom, D. ; Dubus, B. ; Volatier, A.
Author_Institution :
Dept. ISEN, Inst. d´´Electronique de Microelectronique et de Nanotechnologie, Lille
Abstract :
Solidly Mounted Resonators (SMR) are alternatives to membrane resonators to realize Bulk Acoustic Wave (BAW) filters for RF communication systems. SMR decoupling from substrate, which is realized with a multi-layered Bragg reflector, has a major influence on resonator performance (quality factor, spurious modes). A finite element-boundary element (FEM-BEM) method is presented for two-dimensional SMR simulation. The substrate is described by an elastodynamic half-space Green function which is discretized and implemented in the ATILA finite element software. Results are presented for an aluminum nitride resonator with molybdenum electrodes operating at 2.14 GHz and decoupled from the substrate by a tungsten (W)/silicon oxide (SiO2) or a silicon nitride (SiN)/silicon oxycarbide (SiOC) Bragg reflector. When compared to one-dimensional Mason´s model results, FEM-BEM computed values show a decrease of the quality factor and of the effective coupling coefficient. Lowered quality factors at parallel resonance are attributed to elastodynamic radiation into the substrate at the vicinity of the electrode boundary
Keywords :
acoustic resonators; aluminium compounds; boundary-elements methods; bulk acoustic wave devices; crystal resonators; elastodynamics; finite element analysis; molybdenum; radiocommunication; silicon compounds; tungsten; 2.14 GHz; 2D SMR simulation; ATILA finite element software; AlN; BAW filters; FEM-BEM simulation; Mo; RF communication systems; SMR substrate decoupling; SiN; SiO2; SiOC; W; aluminum nitride resonator; bulk acoustic wave filters; coupling coefficient; elastodynamic half space Green function; finite element-boundary element method; molybdenum electrodes; multilayered Bragg reflector; resonator performance; resonator quality factor; resonator spurious modes; silicon nitride-silicon oxycarbide Bragg reflector; solidly mounted resonator; tungsten-silicon oxide Bragg reflector; Acoustic waves; Biomembranes; Elastodynamics; Electrodes; Finite element methods; Q factor; Radio frequency; Resonator filters; Silicon; Solid modeling;
Conference_Titel :
Ultrasonics Symposium, 2006. IEEE
Conference_Location :
Vancouver, BC
Print_ISBN :
1-4244-0201-8
Electronic_ISBN :
1051-0117
DOI :
10.1109/ULTSYM.2006.371