Ultra-thin epitaxial zirconia oxide on silicon with crystalline interface

Epitaxial crystalline yittria-stabilized zirconia (YSZ) films were grown on a silicon wafer by the laser molecular beam epitaxy technique. The interface of crystalline YSZ film in contact with silicon was found atomically sharp and commensurately crystallized without an amorphous layer. X-ray Photoelectron Spectroscopy depth profile and transmission electron microscopy investigation showed there was no silicon dioxide forming at the interface. For the film with electrical equivalent oxide thickness 14.6 Å, the leakage current is about 1.1×10^-3 A/cm² at 1 V bias voltage. The hysteresis and interface state density in this film are measured to be less than 10 mV and 2.0×10¹¹ eV^-1 cm^-2, respectively.