scholarly journals Enhanced Coupling Coefficient in Dual-Mode ZnO/SiC Surface Acoustic Wave Devices with Partially Etched Piezoelectric Layer

2021 ◽  
Vol 11 (14) ◽  
pp. 6383
Author(s):  
Huiping Xu ◽  
Sulei Fu ◽  
Rongxuan Su ◽  
Junyao Shen ◽  
Fei Zeng ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Electromechanical Coupling ◽  
Electromechanical Coupling Factor ◽  
Energy Conversion Efficiency ◽  
Coupling Factor ◽  
Piezoelectric Film ◽  
Dual Mode ◽  
Saw Devices ◽  
Rayleigh Mode

Surface acoustic wave (SAW) devices based on multi-layer structures have been widely used in filters and sensors. The electromechanical coupling factor (K2), which reflects energy-conversion efficiency, directly determines the bandwidth of the filter and the sensitivity of sensor. In this work, a new configuration of dual-mode (quasi-Rayleigh and quasi-Sezawa) SAW devices on a ZnO/SiC layered structure exhibiting significantly enhanced K2 was studied using the finite element method (FEM), which features in the partial etching of the piezoelectric film between the adjacent interdigitated electrodes (IDTs). The influences of piezoelectric film thickness, etching ratio, top electrodes, bottom electrodes, and the metallization ratio on the K2 were systematically investigated. The optimum K2 for the quasi-Rayleigh mode and quasi-Sezawa mode can exceed 12% and 8%, respectively, which increases by nearly 12 times and 2 times that of the conventional ZnO/SiC structure. Such significantly promoted K2 is of great benefit for better comprehensive performance of SAW devices. More specifically, a quasi-Rayleigh mode with relatively low acoustic velocity (Vp) can be applied into the miniaturization of SAW devices, while a quasi-Sezawa mode exhibiting a Vp value higher than 5000 m/s is suitable for fabricating SAW devices requiring high frequency and large bandwidth. This novel structure has proposed a viable route for fabricating SAW devices with excellent overall performance.

Surface Acoustic Wave Device on (AlN/LGS) Substrate

2007 ◽  
Vol 124-126 ◽  
pp. 53-56
Author(s):  
Sean Wu ◽  
Zhi Xun Lin ◽  
Maw Shung Lee
Keyword(s):  
Thin Films ◽  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Electromechanical Coupling ◽  
Chemical Properties ◽  
Temperature Stability ◽  
Rf Magnetron Sputtering ◽  
High Temperature Stability ◽  
Saw Devices ◽  
Stable Chemical

Langasite (La3Ga5SiO14 or abbreviated as LGS) single crystal is an attractive substrate for surface acoustic wave (SAW) devices requiring good temperature stability and higher electromechanical coupling constant than quartz. AlN thin films are attractive materials that have some excellent characteristics, such as high SAW velocity, piezoelectricity, high-temperature stability, and stable chemical properties. In this study, AlN thin films were deposited on LGS to be a new composite SAW substrate (AlN/LGS) by reactive RF magnetron sputtering method. SAW delay-line device was manufactured on this substrate. The performance of the device was measured by network analyzer (Agilent 8753E).The results exhibited the composite substrate (AlN/LGS) increased the Rayleigh wave velocity, decreased the insertion loss of SAW devices, and suppressed the harmonic response.

scholarly journals Full-Wave Analysis of Ultrahigh Electromechanical Coupling Surface Acoustic Wave Propagating Properties in a Relaxor Based Ferroelectric Single Crystal/Cubic Silicon Carbide Layered Structure

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Xiaojun Ji ◽  
Qiang Xiao ◽  
Jing Chen
Keyword(s):  
Silicon Carbide ◽  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Electromechanical Coupling ◽  
Structural Parameters ◽  
Coupling Factor ◽  
Wave Analysis ◽  
Full Wave ◽  
Full Wave Analysis ◽  
Cubic Silicon Carbide

This paper describes a full-wave analysis of ultrahigh electromechanical coupling surface acoustic wave (SAW) of Y-cut X propagating Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (YX-PIMNT) single crystals on a cubic silicon carbide (3C-SiC) substrate. There are several eigenmodes including shear horizontal (SH) and Rayleigh SAWs. Based on the finite-element method (FEM), the phase velocity (vp) and coupling factor (K2) of SAWs varying with the top electrode thickness, thickness, and Euler angle (θ) of the YX-PIMNT substrate have been investigated. K2 of SH SAW can reach an extremely high value of 75.9%. The proper control of structural parameters can suppress unwanted responses caused by other modes without deteriorating the coupling factor. The large K2 value of SH SAW and suppression of unwanted responses have highly promising applications in developing ultrawideband and tunable SAW filters. Finally, the performance of 3C-SiC and 6H-SiC as substrates was investigated, and 3C-SiC was identified as a more attractive substrate candidate than 6H-SiC.

A Zero TCF SAW Contact Stress Sensor in ZnO/SiO2/Si Structure

2011 ◽  
Vol 105-107 ◽  
pp. 1894-1898
Author(s):  
Jie Xiong Ding ◽  
Dong Chen ◽  
Li Du ◽  
Guang Min Liu
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Contact Stress ◽  
Electromechanical Coupling ◽  
Stress Measurement ◽  
Effective Permittivity ◽  
Stress Sensitivity ◽  
Electromechanical Coupling Coefficient ◽  
Stress Sensor ◽  
Rayleigh Mode

A thin sensor based on surface acoustic wave resonator (SAWR) in ZnO/SiO2/Si structure for wireless contact stress measurement in thin gap is numerically analyzed. Firstly, the scheme of the SAWR stress sensor and surface effective permittivity for analyzing surface acoustic wave (SAW) in ZnO/SiO2/Si structure are introduced. Then, the phase velocity and electromechanical coupling coefficient of ZnO(1µm)/SiO2(1.4µm)/Si structure for the fundamental and first Rayleigh mode are obtained. For both Rayleigh modes, the temperature coefficient of frequency (TCF) for the structure at different frequency is calculated. Good temperature stability for the structure is achieved at frequency 1GHz for the first Rayleigh mode with averaged TCF about 0.04ppm/°C and stress sensitivity about 22ppm/MPa.

SAW Properties on X,Y,Z-Cut of Sr3(Nb,Ta)Ga3Si2O14 and Ca3(Nb,Ta)Ga3Si2O14 Piezoelectric Crystal

2012 ◽  
Vol 512-515 ◽  
pp. 1207-1211 ◽  
Author(s):  
Wen Qi Huang ◽  
Hong Yang
Keyword(s):  
Phase Velocity ◽  
Excellent Agreement ◽  
Power Flow ◽  
Electromechanical Coupling ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Piezoelectric Crystal ◽  
Flow Angle ◽  
Lower Phase ◽  
Saw Devices

We calculate the phase velocity(V), power flow angle(PFA) and electromechanical coupling factor(k2) on X,Y,Z-cut of Sr3NbGa3Si2O14(SNGS),Sr3TaGa3Si2O14 (STGS), Ca3NbGa3Si2O14(CNGS) and Ca3TaGa3Si2O14(CTGS)crystal,. The calculated results are in excellent agreement with the experimental results. As these crystals are denser than quartz, they have lower phase velocity. The results also indicates that they have high k2 and cuts of zero PFA. Taking various SAW properties into consideration, some typical propagation directions like 167.5° of X-cut SNGS ,0 of Y-cut SNGS, 170° of X-cut STGS, 0 of Y-cut STGS,11 of X-cut CNGS, 0 of Y-cut CNGS, 175.0 of X-cut CNGS and 0 of Y-cut CTGS are selected, which can be used in the application of SAW devices.

A comparison of Pd and Au electrodes-based LiNbO3 surface acoustic wave devices

2016 ◽  
Vol 30 (32n33) ◽  
pp. 1650349 ◽  
Author(s):  
Bo Liu ◽  
Mohammad Ali Mohammad ◽  
Dan-Yang Wang ◽  
Xiang-Guang Tian ◽  
Lu-Qi Tao ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Resonance Frequency ◽  
Quality Factor ◽  
Surface Acoustic Wave ◽  
Electromechanical Coupling ◽  
Coupling Coefficients ◽  
Third Order ◽  
Au Electrode ◽  
Saw Devices ◽  
Resonance Frequencies

We report the comparison of electrode metals for LiNbO3 surface acoustic wave (SAW) devices. Palladium (Pd) was systematically studied as a SAW electrode metal for the first time, compared with gold (Au). Simulations were first conducted to gain an understanding of the differences of the materials and the metallization ratio. Two sets of identical SAW devices were then fabricated using Au and Pd as electrodes with different electrode widths and same SAW period. The insertion losses, types of resonance mode, the resonance frequencies, peak amplitudes, quality factors and trends with different metallization ratios were systematically compared and analyzed. We found that Pd electrode devices only exhibit the parallel resonance frequency and have higher resonance frequency for both the first-order and third-order harmonics. Au electrode devices tend to have a smooth response and a quality factor two times higher than Pd. Both Pd and Au electrode devices have nearly identical electromechanical coupling coefficients, and the quality factor and third-order harmonics both improve with increasing metallization ratio.

Using the Effective Surface Permittivity Method to Analyse Multilayer Piezoelectric Substrates for Surface Acoustic Wave Filters

2014 ◽  
Vol 31 (2) ◽  
pp. 139-145 ◽  
Author(s):  
H.-Y. Tsai ◽  
W.-H. Hsu ◽  
Y.-K Yu ◽  
R. Chen
Keyword(s):  
Acoustic Wave ◽  
Phase Velocity ◽  
Surface Acoustic Wave ◽  
Double Layer ◽  
High Frequency ◽  
Electromechanical Coupling ◽  
Electromechanical Coupling Coefficient ◽  
Bulk Materials ◽  
Effective Surface ◽  
Saw Devices

AbstractIn this study, the properties of surface acoustic wave (SAW) filters, including phase velocity and electromechanical coupling coefficient (K2) are investigated. The effective surface permittivity (ESP) method was employed to estimate the K2 of bulk materials (single layer) and multi-layer (double-layer and trilayer) structures. In the cases of bulk materials, the calculation results agree with the experimental data, and the errors are less than 7% for quartz. In the cases of double-layer materials, the phase velocity and K2 of various materials, such as ZnO/Diamond and LiNbO3/Diamond, were acquired, and the results demonstrate that LiNbO3/diamond is the optimal choice for high-frequency SAW devices. For the cases of trilayer, the structure of ZnO/PZT/diamond has relatively high K2 and phase velocity. Therefore, this structure is the optimal trilayer structure for high-frequency SAW devices. The study demonstrates that ESP method can be successfully used for estimating SAW properties in piezoelectric multi-layer structures even though the structures contain nonpiezoelectric film (diamond). The proposed numerical computation has the potential to shorten the developing time of SAW device.

Sign in / Sign up

Export Citation Format

Share Document