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.

Low loss surface acoustic wave SAW devices based on Al1-xMxN (M=Cr, Y, Sc) thin films

2021 ◽  
pp. 412990
Author(s):  
Saad Amara ◽  
Fares Kanouni ◽  
Farouk Laidoudi ◽  
Khaled Bouamama
Keyword(s):  
Thin Films ◽  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Low Loss ◽  
Saw Devices

c-Axis-tilted ScAlN films grown on silicon substrates for surface acoustic wave devices

2022 ◽  
Author(s):  
Takumi Tominaga ◽  
Shinji Takayanagi ◽  
Takahiko Yanagitani
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Mobile Networks ◽  
Tilt Angle ◽  
Silicon Substrate ◽  
Electromechanical Coupling ◽  
Rf Magnetron Sputtering ◽  
Electromechanical Coupling Coefficient ◽  
Silicon Substrates ◽  
Device Structure

Abstract ScAlN films are currently being investigated for their potential use in surface acoustic wave (SAW) devices for next-generation mobile networks because of their high piezoelectricity. This paper describes the numerical simulation of SAW propagation in c-axis-tilted ScAlN films on silicon substrates and a fabrication technique for preparing c-axis-tilted ScAlN films on silicon substrates. The electromechanical coupling coefficient K 2 of SAW propagating in the ScAlN film/silicon substrate increased due to the c-axis tilt angle. The maximum K 2 value is approximately 3.90%. This value is 2.6 times the maximum K 2 value of the c-axis-oriented ScAlN film/silicon substrate structure. The c-axis-tilted ScAlN films with an Sc concentration of 40% were prepared on a silicon substrate via RF magnetron sputtering based on the self-shadowing effect, and the maximum c-axis tilt angle was 57.4°. These results indicate that this device structure has potential for SAW device applications with well-established micromachining technology derived from silicon substrates.

scholarly journals Stability studies of ZnO and AlN thin film acoustic wave devices in acid and alkali harsh environments

RSC Advances ◽  
2020 ◽  
Vol 10 (33) ◽  
pp. 19178-19184
Author(s):  
Shuo Xiong ◽  
Xudong Liu ◽  
Jian Zhou ◽  
Yi Liu ◽  
Yiping Shen ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Lab On A Chip ◽  
Harsh Environments ◽  
Stability Studies ◽  
Piezoelectric Thin Films ◽  
Saw Devices ◽  
Acoustic Wave Devices

Surface acoustic wave (SAW) devices based on piezoelectric thin-films such as ZnO and AlN are widely used in sensing, microfluidics and lab-on-a-chip applications.

Surface Acoustic Wave Sensors Deposited on AlN Thin Films

2009 ◽  
Vol 1202 ◽  
Author(s):  
J. L. Justice ◽  
O. M. Mukdadi ◽  
D. Korakakis
Keyword(s):  
Thin Films ◽  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Piezoelectric Materials ◽  
Theoretical Calculations ◽  
Si Substrates ◽  
Sensing Applications ◽  
Saw Devices ◽  
Inherent Frequency ◽  
Wave Sensors

AbstractOver the past few decades, there has been considerable research and advancement in surface acoustic wave (SAW) technology. At present, SAW devices have been highly successful as frequency band pass filters for the mobile telecommunications and electronics industries. In addition to their inherent frequency selectivity, SAW devices are also highly sensitive to surface perturbations. This sensitivity, along with a relative ease of manufacture, makes SAW devices ideally suited for many sensing applications including mass, pressure, temperature, and biosensors. In the area of biosensing, surface plasmon resonance (SPR) and quartz crystal microbalances (QCM) are still in the forefront of research and development, but advancement in SAW sensors could prove to have significant advantages over these technologies. This study investigates the advantages of using aluminum nitride (AlN) as a material for SAW sensors. AlN retains its piezoelectric properties at relatively high temperatures when compared to more common piezoelectric materials such as lead zirconium titanate (PZT), lithium tantalate (LiTaO3) and zinc oxide (ZnO). AlN is also a very robust material making it suitable for biosensing applications where the sensing target is selectively absorbed by an active layer on the device which may attack the piezoelectric layer. AlN thin films of different thicknesses have been deposited on Si substrates by DC reactive sputtering. Rayleigh-wave SAW devices have been fabricated by the deposition of platinum contacts and interdigital transducers (IDTs) onto AlN thin films using standard photolithographic processes. Experiments have been conducted to measure Rayleigh velocities, resonant frequencies, and insertion loss. Experimental results are compared to theoretical calculations.

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.

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.

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