The Variation of Propagation Velocity According to Substrate Material of Band Pass Filter
Keywords:SAW filter, MCB process lift off method, ZnO thin film, c-axis preferential orientation, RF magnetron sputtering method
Background/Objectives: The SAW filter has a frequency characteristic determined by the geometry of the IDT electrode, and is widely used as a band-pass filter for passing only a signal having a specific frequency.
Methods/Statistical analysis: The features of this filter are high stability and reliability and enable mass production using semiconductor processes.
Findings: The MCB process lift off method was used to fabricate the filter to solve the difficulties of the SAW filter process. In particular, we fabricated ZnO thin films with excellent c-axis preferential orientation, high resistivity of more than 106Î©cm, and flat surfaces, and fabricated SAW filters using ZnO thin films as deposition conditions suitable for application to SAW filters. ZnO thin films deposited under conditions of RF power of 150W, chamber pressure of 10mTorr, substrate temperature of 200 ° C and gas mixture ratio of Ar/O2 of 50/50 as sputtering gas have excellent c-axis preferential orientation, high specific resistance and flat surface shape. Then, ZnO piezoelectric thin film was deposited on SiO2 substrate by RF magnetron sputtering method and the SAW filter was fabricated by the MCB lift off method to analyze the frequency characteristics. And compared with the SAW filter fabricated on the LiNbO3 substrate, which is a piezoelectric substrate.
Improvements/Applications: The propagation speed of the SAW filter using the ZnO thin film was determined by the variation of the center frequency due to the deposition of the ZnO thin film.
 Akstaller, W., et al, (2017). X-Parameter Characterization of SAW Filters with Enhanced Dynamic Range. IEEE transactions on microwave theory and techniques, 65(11), 4541-4549.
 Wang, D.Q., et al, (2014). A SAW Filter of Elliptic Structure IDT. Applied Mechanics and Materials, 665, 623-628.
 Wang, D., Yao, Z., Chen, Y. (2013). Design and implementation of circular IDT structure SAW filter. ELECTRONIC COMPONENTS AND MATERIALS,32(4), 50-53.
 Kawakami, et al, (2016). Effect of substrate materials on piezoelectric properties of BaTiO~3 thick films deposited aerosol deposition. Japanese Journal of Applied Physics, 55(10), 10TA10.
 Tominaga, K. Sueyoshi, Y. , Imai, H. , Shintani, Y. (1993).Film Preparation of ZnO in Air Gas by Planar Magnetron-Sputtering System with Facing ZnO Targets. INTERNATIONAL SYMPOSIUM ON PLASMA CHEMISTRY, 3,841-846.
 Lu, X. ,Mouthaan, K. , Soon, Y. T. (2014).Wideband Randpass Filters With SAW-Filter-Like Selectivity Using Chip SAW Resonators. IEEE transactions on microwave theory and techniques, 62(1), 28-36.
 Rondi, Luca, Sntosa, Fadil, Wang, Zhu. (2016). A Variational Approach to the Inverse Photolithography Problem. SIAM journal on applied mathematics, 76(1), 110-137.
 Szabo. Z., et al, (2013). Regular ZnOnanopillar arrays by nanosphere photolithography. PHOTONICS AND NANOSTRUCTURES, 11(1)1-7.
 Chang, S.-C., Kempisty, J. M. (2002). Lift-Off Methods for MEMS Devices. Materials Research Society Symposium Proceedings, 729, 47-56.
 Morinaga. E., et al,, (2012). A Design Method for Thin Film Patterning Process via Lift-Off Technique. Key Engineering Materials, 523, 787-792.
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