氮化铌表面氧化物的XPS研究

本文用X射线光电子能谱(XPS)对室温下自然氧化和射频氧化的氮化铌薄膜表面进行了成分分析。指出:与在类似条件下纯铌膜的氧化不同,NbN膜的表面氧化物中不存在NbO和NbO₂,而是以Nb₂O₃作为从NbN到Nb₂O_5-y的过渡相。氮化铌在氧化过程中表现出一种抑制Nb₂O,NbO等低价传导性氧化物生成的能力,这对于用氧化物作势垒的超导隧道结的研制具有实际参考价值。 关键词：

XPS STUDY OF THE OXIDES ON THE SURFACE OF NbN THIN FILM

The composition of the oxides formed at room temperature in the atmosphere or by rf oxidation on the surfaces of NbN thin films were characterized by means of X-ray photoelectron spectroscopy. The experimental Nb3d spectra show that the interfacial phase formed between NbN substrate and the niobium pentoxide is different from the case of pure niobium. It is Nb₂O₃ but not a mixture of NbO and NbO₂. The surface of NbN seems to have the ability of protecting itself from the formation of conducting suboxides such as Nb₂O, NbO etc. This is useful for improving the quality of the superconducting tunnel junction with oxide barrier.