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Keywords:

  • surface acoustic waves;
  • piezoelectric properties;
  • electromechanical properties;
  • doping;
  • ZnO

Abstract

Surface acoustic wave (SAW) filters based on Mn-doped ZnO films have been fabricated and effects of Mn-doping on SAW properties are investigated. It is found that the electromechanical coupling coefficient (K2) of Zn0.913Mn0.087O films is 0.73 ± 0.02%, which is 73.8% larger than that of undoped ZnO films (0.42 ± 0.02%). Zn0.913Mn0.087O film filters also exhibit a lower absolute value of insertion loss (|IL|) of 16.1 dB and larger bandwidth (BW) of 5.9 MHz compared with that of undoped ZnO film filter. However, Zn0.952Mn0.048O film filters exhibit a smaller K2 of 0.34 ± 0.02%, larger |IL| of 26.9 dB and smaller BW of 3.5 MHz. It is suggested that the SAW properties can be improved by appropriate Mn-doping and Mn–ZnO/Si multilayer structure with large d33 is promising for wide-band and low-loss SAW applications. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)