Effects of post-deposition annealing in O/sub 2/ on the electrical characteristics of LaAlO/sub 3/ films on Si

Abstract

LaAlO3 films were deposited on p-type Si 100 by sputtering from a LaAlO3 target. C V characteristics were determined in nonannealed and O2-annealed capacitors having LaAlO3 films as dielectric and RuO2 as top electrode. Thermal annealing in O2 atmosphere reduced flat band voltage to acceptable values for advanced Si-based devices. 16O–18O isotopic substitution was characterized by Rutherford backscattering spectrometry and nuclear resonant reaction profiling. Chemical analysis of the films was accomplished by x-ray photoelectron spectroscopy. The electrical improvements observed after thermal annealing in O2 were attributed to the incorporation of oxygen from the gas phase, possibly healing oxygen vacancies in the films and providing mobile oxygen to the interface