Impurity and silicate formation dependence on O-3 pulse time and the growth temperature in atomic-layer-deposited La2O3 thin films

Abstract

Atomic-layer-deposited La2O3 films were grown on Si with different O-3 pulse times and growth temperatures. The interfacial reactions and impurity behaviors were observed using in situ X-ray photoelectron spectroscopy. Longer pulse time of O-3 formed the solid SiO2 interfacial barrier layer, which suppressed La-silicate formation. Meanwhile, the carboxyl compound acting as an impurity phase was replaced with LaCO3 on increasing the O-3 pulse time due to further oxidation and reaction of La. Higher growth temperatures enhanced La-silicate formation by mixed diffusion of Si and La2O3, during which most of the La2O3 phase was consumed at 400 degrees C. C and N impurities decreased with increasing growth temperature and completely disappear at 400 degrees C. Published by AIP Publishing.