Synthesis of ScAlN thin films on Si (100) substrates at room temperature

Scandium aluminum nitride alloy (ScAlN) thin films have been synthesized using reactive sputtering of a scandium aluminum alloy (Sc0.40Al0.60) target on Si (100) substrates. We have investigated the effects of two sputtering control factors, namely sputtering process pressure and discharge power, on the c-axis growth of the piezoelectric layers. According to our X-ray diffraction analysis, the films are highly textured in the [001] direction at low process pressures and moderate to high discharge powers. X-ray energy dispersive spectroscopy data reveal that the Sc content in the synthesized ScAlN thin films is proportional to the Sc content in Sc0.40Al0.60 alloy target. Finally, surface acoustic wave resonators have been manufactured to demonstrate the feasibility of this material for micro electro mechanical systems applications based on ScAlN/Si bilayer systems.