Growth and Characterization of LaS and NdS Thin Films on Si, GaAs, and InP Substrates

摘要

Mono Chalcogenides of Rare-earths as thin-films on Ⅲ-Ⅴ semiconductor surfaces represent attractive materials to realize Negative Electron Affinity. Recently, we reported the successful growth of cubic Lanthanum Sulfide (LaS) and Neodymium Sulfide (NdS) in a bulk form. These materials are closely lattice-matched to InP and GaAs, respectively. In this paper, we report preliminary results on RF magnetron sputter deposition of two rare-earth sulfides (LaS and NdS) thin-films on Si, InP, and GaAs substrates. For LaS thin-films, RF sputtering parameters leading to samples with stoichio-metric amounts of La and S atoms are identified. Thin-film samples were characterized by X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM), and X-Ray Diffraction (XRD).