Growth of O-Polar and Zn-Polar Ferroelectric MgZnO Thin Films Controlled by Sputtering Geometry

Polarization-inverted multilayer devices are attractive for improving the power durability of BAW devices. To fabricate this structure, a polarization control technique is required. Two methods for controlling polarization of MgZnO are available: ion beam induced polarization inversion and external electric field induced polarization inversion. In this study, Zn-polar and O-polar MgZnO thin films were grown and we fabricated polarization-inverted multilayer structure by using ion beam induced polarization inversion. As a result, the resonator excites
$\boldsymbol{2}^{\mathbf{nd}}$
overtone mode, and suppresses fundamental mode. Furthermore, we report conversion loss
$(CL)$
vs external electric field (
$\boldsymbol{E}$
) hysteresis curve obtained by using external electric field induced polarization inversion.