LINBO3 SINGLE CRYSTAL PIEZOELECTRIC SUBSTRATE WITH POLARIZATION INVERTING REGION AND MANUFACTURE THEREOF

摘要

PURPOSE:To easily form a reverse polarity polarization inverting layer to the self-polarization of a substrate by forming the polarization inverting region without adhering other substance to the +C face of an LiNbO3 single crystal substrate. CONSTITUTION:In an LiNbO3 single crystal substrate (Z plate), its self- polarization is directed in a +C axis (Z axis). When the substrate is cooled after it is allowed to stand for a predetermined time in air or inert gas, such as Ar at slightly lower temperature than its Curie point (1150-1200 deg.C), a reverse polarization inverting layer to its own polarization is formed on the substrate +C face side. The thickness of the layer varies depending upon heat treating temperature, treating time and atmosphere. The substrate formed with the polarization inverting region of predetermined depth is adhered on its both faces, for example, with single electrodes. When an AC electric field is applied to the substrate, it can be used as an actuator for implanting a fine displacement.