Abstract
Surface acoustic wave (SAW) propagation characteristics in a multilayer
structure including a piezoelectric aluminum nitride (AlN) thin film and
an epitaxial cubic silicon carbide (3C–SiC) layer on a silicon (Si)
substrate are investigated by theoretical calculation in this work.
Alternating current (ac) reactive magnetron sputtering was used to
deposit highly c-axis-oriented AlN thin films, showing the full
width at half maximum (FWHM) of the rocking curve of 1.36° on epitaxial
3C–SiC layers on Si substrates. In addition, conventional two-port SAW
devices were fabricated on the AlN/3C–SiC/Si multilayer structure and
SAW propagation properties in the multilayer structure were
experimentally investigated. The surface wave in the AlN/3C–SiC/Si
multilayer structure exhibits a phase velocity of 5528 m s−1
and an electromechanical coupling coefficient of 0.42%. The results
demonstrate the potential of AlN thin films grown on epitaxial 3C–SiC
layers to create layered SAW devices with higher phase velocities and
larger electromechanical coupling coefficients than SAW devices on an
AlN/Si multilayer structure. Moreover, the FWHM values of rocking curves
of the AlN thin film and 3C–SiC layer remained constant after annealing
for 500 h at 540 °C in air atmosphere. Accordingly, the layered SAW
devices based on AlN thin films and 3C–SiC layers are applicable to
timing and sensing applications in harsh environments.
Original language | English |
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Article number | 025019 |
Number of pages | 8 |
Journal | Journal of Micromechanics and Microengineering |
Volume | 23 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2013 |
MoE publication type | A1 Journal article-refereed |