Second-order Nonlinearity of Amorphous SiOF Films in FBARs

This paper discusses impact of SiO2/SiOF on the 2nd harmonic (H2) generation in temperature compensated (TC) film bulk acoustic resonators (FBARs). First, two types of TC-FBARs are fabricated and their H2 behavior is compared with that of the standard FBAR. Next, H2 characteristics of TC-layer are investigated by the use of series of TC-FBARs where SiOF and Cr layers are placed on the outside of electrodes. Simulations agree very well with measurements, and can explain well how the H2 response changes with the Cr thickness. Not only AlN but also SiOF contribute generation of the H2 response is shown, and H2 becomes very small at an appropriate Cr thickness. Finally, TC-FBAR filter operating at 5.9 GHz is fabricated and its H2 response is compared with the simulation. The simulation agrees well with the experiment. It is also demonstrated that insertion of the TC-layer is effective to suppress the H2 generation.

Section: H2 Analysis and Verification In Tc-fbarmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Analysis and verification on second-order nonlinearity in radio frequency bulk acoustic wave devices employing temperature compensation films

Ueda,

Nishizawa,

Orito

et al. 2024

“…We also confirmed the dependence on film thickness of H2, with good agreement between our simulations and measurement results. 36) Next, H2 performances of the filter are discussed. We fabricated a ladder filter consisting of FBAR resonators and compared measured H2 and simulated results.…”

Section: Verification Of Theoretical Analysismentioning

confidence: 99%

Perturbation analysis of second-order nonlinearity and its effectiveness for radiofrequency bulk acoustic wave devices

Ueda

Nishizawa²,

Taniguchi³

et al. 2023

Suppression of nonlinear signal generation in radio frequency (RF) surface and bulk acoustic wave (SAW/BAW) devices is one of the most important subjects on the RF front-end modules of recent cellular handsets. Especially, issue on 2nd order nonlinear products of BAW is well known.　 In this work, we succeeded in extracting the dominant parameters for 2nd order nonlinear analysis proposed by K. Hashimoto and verified that it was applicable in wide frequency range and also effective for FBAR device design. Combining the extracted nonlinear coefficients on the perturbation analysis by driving near fundamental frequency (f0) of FBAR and half resonant frequency (1/2f0) could reproduce 2nd order nonlinear characteristics in the wide frequency range, and also it was confirmed that the proposed simulations were good agreement with measurement results for various type resonators and FBAR filters.

“…Hashimoto, et al proposed one-dimensional (1D) perturbation analysis based on wave equations in combination with the piezoelectric constitutive equations of the h form instead of the e form, and demonstrated accurate simulation for the main resonance in very high speed. 13,14) They also proposed an inductance capacitance resistance (LCR) equivalent circuit for the nonlinear analysis. 15) It is similar to the conventional modified Butterworth-Van Dyke (MBVD) model 16) but it includes two voltage sources representing nonlinear stress and electric field responsible to nonlinear signal generation.…”

Section: Introductionmentioning

confidence: 99%

Perturbation analysis of nonlinear responses caused by transverse modes in AlN FBAR based on 2D scalar wave model

Wu,

Luo,

et al. 2023

Self Cite

This paper describes perturbation analysis of nonlinear signal generation in apodized BAW devices using a multi-branch LCR equivalent circuit where all necessary simulation parameters are derived by the two-dimensional (2D) scalar wave model. Nonlinear signals are evaluated by adding two voltage sources representing nonlinear strain and electric flux, and their amplitude is determined by currents in the circuit for linear analysis. Simulated second and third harmonic responses agree well with experimental ones. The magnification mechanism of spurious resonances is also discussed.