Impact of remote oxygen scavenging on the interfacial characteristics of atomic layer deposited LaAlO3

In this paper, the influence of a remote interfacial layer (IL) scavenging method on the interfacial characteristics of LaAlO3 grown by atomic layer deposition (ALD) on Si substrates has been studied. After the fabrication of Pt/LaAlO3/Si and Pt/Ti/TiN/LaAlO3/Si metal-insulator-semiconductor (MIS) capacitors, the microstructures and electrical properties of these MIS capacitors have been comparatively investigated. High resolution transmission electron microscopy (HRTEM) analysis shows that the thickness of IL between LaAlO3 films and Si substrates is reduced by remote IL scavenging technique, contributing to lower equivalent oxide thickness (EOT) and to higher dielectric constant values. However, larger amount of oxygen vacancies and dangling bonds are induced in the MIS structure with IL scavenging reaction, resulting in a slight degradation of the gate leakage current-voltage and the breakdown characteristics.