Effects of Thermal Annealing on the Characteristics of High Frequency FBAR Devices
Source abstract
Abstract
In this study, piezoelectric zinc oxide (ZnO) thin film was deposited on the Pt/Ti/SiNx/Si substrate to construct the FBAR device. The Pt/Ti multilayers were deposited on SiNx/Si as the bottom electrode and the Al thin film was deposited on the ZnO piezoelectric layer as the top electrode by a DC sputtering system. The ZnO thin film was deposited onto the Pt thin film by a radio frequency (RF) magnetron sputtering system. The cavity on back side for acoustic reflection of the FBAR device was achieved by KOH solution and reactive ion etching (RIE) processes. The crystalline structures and surface morphologies of the films were analyzed by X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). The optimized as-deposited ZnO thin films with preferred (002)-orientation were obtained under the sputtering power of 80 W and sputtering pressure of 20 mTorr. The crystalline characteristics of ZnO thin films and the frequency responses of the FBAR devices can be improved by using the rapid thermal annealing (RTA) process. The optimized annealing temperature and annealing time are 400 °C and 10 min, respectively. Finally, the FBAR devices with structure of Al/ZnO/Pt/Ti/SiNx/Si were fabricated. The frequency responses showed that the return loss of the FBAR device with RTA annealing was improved from −24.07 to −34.66 dB, and the electromechanical coupling coefficient (kt2) was improved from 1.73% to 3.02% with the resonance frequency of around 3.4 GHz.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Acoustic Wave Resonator Technologies · Advanced Sensor and Energy Harvesting Materials · GaN-based semiconductor devices and materials
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Department of Electrical Engineering, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
Medical Devices and Opto-Electronics Equipment Department, Metal Industries Research and Development Center, Kaohsiung 811, Taiwan
Department of Electronic Engineering, HungKuo Delin University of Technology, New Taipei 236, Taiwan
References (33)
Show source-provided references
1. Evaluation of mass sensitive micro-array biosensors for their feasibility in multiplex detection of low molecular weight toxins using mycotoxins as model compounds10.1016/j.talanta.2020.121521 ↗
2. Miniature sensing system with FBAR-based oscillators and frequency shift detector10.1109/JSEN.2018.2858279 ↗
3. The research of dual-mode film bulk acoustic resonator for enhancing temperature sensitivity10.1088/1361-6641/abd15c ↗
4. Ruby, R.C., Radley, P.B., Shmyansky, Y.O., Chien, A., and Larson, J.D. (2000, January 22–25). Thin film bulk wave acoustic resonator (FBAR) for wireless applications. Proceedings of the IEEE Ultrasonics Symposium. Proceedings. An International Symposium, San Juan, PR, USA.
5. Advanced vapor recognition materials for selective and fast responsive surface acoustic wave sensors: A review10.1016/j.aca.2013.05.005 ↗
6. Pulsed laser deposition of piezoelectric ZnO thin films for bulk acoustic wave devices10.1016/j.apsusc.2013.10.075 ↗
7. Temperature effects on a high Q FBAR in liquid10.1016/j.sna.2009.10.003 ↗
8. Shealy, J.B., Hodge, M.D., Patel, P., Vetury, R., Feldman, A.Y., Gibb, S.R., Boomgarden, M.D., Lewis, M.P., Shealy, J.B., and Shealy, J.R. (2016, January 22–24). Single crystal AlGaN bulk acoustic wave resonators on silicon substrates with high electromechanical coupling. Proceedings of the IEEE Radio Frequency Integrated Circuits Symposium (RFIC), San Francisco, CA, USA.10.1109/RFIC.2016.7508261 ↗
9. Increase in the piezoelectric response of scandium-doped gallium nitride thin films sputtered using a metal interlayer for piezo MEMS10.1063/1.5066613 ↗
10. Schneider, M., DeMiguel-Ramos, M., Flewitt, A.J., Iborra, E., and Schmid, U. (2017). Scandium aluminum nitride-based film bulk acoustic resonators. Proceedings, 1.10.3390/proceedings1040305 ↗
11. Effects of reflecting layers on resonance characteristics of a solidly mounted resonator with 1/4 𝜆 mode configuration10.1007/s00339-009-5519-1 ↗
12. The liquid sensor using thin film bulk acoustic resonator with c-axis tilted AlN films10.1155/2013/245095 ↗
13. Fabrication and characterization of a shear mode AlN solidly mounted resonator-silicone microfluidic system for in-liquid sensor applications10.1016/j.sna.2010.02.009 ↗
14. Assessment of the absolute mass attachment to an AlN-based solidly mounted resonator using a single shear mode10.1109/LED.2020.2976490 ↗
15. Analytical study of dual-mode thin film bulk acoustic resonators (FBARs) based on ZnO and AlN films with tilted c-axis orientation10.1109/TUFFC.2010.1623 ↗
16. Effect of c-axis tilted orientation ZnO thin film on shear-mode bulk acoustic resonator in liquid environment10.1166/mex.2020.1779 ↗
17. Flexible film bulk acoustic resonators and filter-like structure made directly on polymer substrates10.1080/10584587.2016.1159538 ↗
18. Fabrication and RF characterization of zinc oxide based film bulk acoustic resonator10.1016/j.spmi.2018.04.001 ↗
19. Lateral field excitation of thickness shear mode waves in a thin film ZnO solidly mounted resonator10.1063/1.2562040 ↗
20. High Q, high frequency, high overtone bulk acoustic resonator with ZnO films10.1631/jzus.C12MNT07 ↗
21. Influence of substrate temperature on structural, optical properties and dielectric results of nano-ZnO thin films prepared by Radio Frequency technique10.1016/j.spmi.2013.11.007 ↗
22. Structural and optical characterization of ZnO thin films for optoelectronic device applications by RF sputtering technique10.1016/j.spmi.2014.07.032 ↗
23. Performance evaluation of bottom gate ZnO based thin film transistors with different W/L ratios for UV sensing10.1016/j.spmi.2017.12.054 ↗
24. Film bulk acoustic resonator fabrication for radio frequency filter applications10.1143/JJAP.39.4115 ↗
25. Rapid thermal annealing effects on the structural and optical properties of ZnO films deposited on Si substrates10.1016/j.jlumin.2008.09.003 ↗
26. Effects of rapid thermal annealing on the morphology and electrical properties of ZnO/In films10.1016/S0040-6090(02)00072-X ↗
27. Thermal annealing effect on ZnO surface acoustic wave-based ultraviolet light sensors on glass substrates10.1063/1.4880898 ↗
28. Effects of rapid thermal annealing on surface acoustic wave ultraviolet sensors using ZnO nanorods grown on AlN/Si structures10.1007/s10832-013-9782-3 ↗
29. The effect of geometry and post-annealing on surface acoustic wave characteristics of AlN thin films prepared by magnetron sputtering10.1016/j.apsusc.2011.05.050 ↗
30. Postdeposition annealing of radio frequency magnetron sputtered ZnO films10.1116/1.580050 ↗
31. Structural, optical and electronic structure studies of Al doped ZnO thin films10.1016/j.spmi.2015.03.047 ↗
32. The effect of ZnO thin film and its structural and optical properties prepared by Sol-Gel spin coating method10.4236/ojmetal.2013.32A2002 ↗
33. Surface micromachined AlN thin film 2 GHz resonator for CMOS integration10.1016/j.sna.2004.06.014 ↗