Synthesis and surface acoustic wave properties of AlN films deposited on LiNbO3 substrates

IEEE Trans Ultrason Ferroelectr Freq Control. 2002 Mar;49(3):345-9. doi: 10.1109/58.990951.

Abstract

The c-axis-oriented aluminum nitride (AIN) films were deposited on z-cut lithium niobate (LiNbO3) substrates by reactive RF magnetron sputtering. The crystalline orientation of the AIN film determined by x-ray diffraction (XRD) was found to be dependent on the deposition conditions such as substrate temperature, N2 concentration, and sputtering pressure. Highly c-axis-oriented AIN films to fabricate the AIN/LiNbO3-based surface acoustic wave (SAW) devices were obtained under a sputtering pressure of 3.5 mTorr, N2 concentration of 60%, RF power of 165 W, and substrate temperature of 400 degrees C. A dense pebble-like surface texture of c-axis-oriented AIN film was obtained by scanning electron microscopy (SEM). The phase velocity and the electromechanical coupling coefficient (K2) of SAW were measured to be about 4200 m/s and 1.5%, respectively. The temperature coefficient of frequency (TCF) of SAW was calculated to be about -66 ppm/ degrees C.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustics / instrumentation*
  • Aluminum Compounds / chemistry*
  • Crystallography, X-Ray / methods*
  • Equipment Design / methods
  • Materials Testing / methods*
  • Microwaves*
  • Models, Theoretical
  • Niobium / chemistry*
  • Oxides / chemistry*
  • Sensitivity and Specificity
  • Substrate Specificity
  • Temperature
  • Transducers

Substances

  • Aluminum Compounds
  • Oxides
  • Niobium
  • lithium niobate
  • aluminum nitride