原位光电子能谱研究La_2O_3/LaAlO_3/Si电子结构

在超高真空条件下,通过脉冲激光技术沉积La_2O_3/LaAlO_3/Si多层膜结构,原位条件下利用同步辐射光电子能谱研究了LaAlO_3作为势垒层的La_2O_3与Si的界面电子结构。实验结果显示,LaAlO_3中Al的2p峰在沉积和退火前后没有变化;衬底硅的芯能级峰在沉积LaAlO_3时没有变化,但在沉积La_2O_3薄膜和退火过程中,硅峰变弱;O的1S芯能级的峰由多种不用的氧化物薄膜层和反应物中的氧杂化而成。结果表明:LaAlO_3从沉积到退火当中,不参与任何反应,Si与LaAlO_3界面相当稳定;在体系中,阻挡层LaAlO_3起到阻挡硅扩散的作用,进一步表明La_2O_3与硅的界面不太稳定。

In-situ Study of Interface Electronic Structure of La2O3/LaAlO3/Si by X-ray Photoelectron Spectroscopy

The multiple layer films with La2O3/LaAlO3/Si structure were fabricated in the super-high vacuum by the pulsed laser deposition(PLD) technique.We have investigated the electronic structure of the interface between Si substrate and La2O3 layer using the barrier layer of LaAlO3 by X-ray photoelectron spectroscopy (XPS).The experimental result shows that the Al 2p peaks in LaAlO3 were not changed before and after annealing process.The silicon peaks are not changed when depositing LaAlO3 films, but that of peaks are changed when depositing La2O3 films and annealing.O 1S peaks are from the hybridization of oxygen atom of intrinsic oxide and products.The results indicate that LaAlO3 films are not participating in the interface reaction and that mean the interface are thermally stable.In this structure, the barrier layer are prevented the diffusion, shows that the interface is not stable.