Dynamic growth mechanism and interface structure of crystalline zirconia on silicon

Abstract

In present report, we have studied the initial stage of the growth of crystalline yttriastabilized zirconia (YSZ) films on the natively oxidized Si (100) wafer by pulsed-laser deposition. X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM) show that, for the first few monolayers of crystalline YSZ deposited on Si (100), the dynamic processes appear to be the decomposition of SiO2 to SiO, the formation of ZrO2, and the desorption of SiO. The native amorphous silicon oxide layer is removed completely with the continued deposition of YSZ and the oxygen in this layer is used as oxygen source for forming stable crystalline oxide film. XPS depth profile and HRTEM investigation showed that the interface of crystalline YSZ film in contact with silicon was found to be atomically sharp and commensurately crystallized without an amorphous layer. The interface structure is suggested to have a sequence of -Si-O-Zr-O-. For the film with electrical equivalent oxide thickness 1.46 nm, 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.