Studies of the interfacial structure of LaAlO3 thin films on silicon by x-ray reflectivity and angle-resolved x-ray photoelectron spectroscopy

• Published in: Journal of applied physics 2005-06, Vol.97 (12)
• Main Authors: Li, X. L., Xiang, W. F., Lu, H. B., Mai, Z. H.
• Format: Article
• Language: English
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.1941470

The microstructures of amorphous LaAlO3 thin films deposited on silicon substrates by the laser molecular-beam epitaxy were studied by the x-ray reflectivity and the angle-resolved x-ray photoelectron spectroscopy. It was shown that the film∕substrate interface contains a La-rich LaxAlyOzSi layer and a SiOx layer. It was shown that the electron density of the LaAlO3 layer and the LaxAlyOzSi layer is not homogeneous along the growth direction due to the diffusion of La, Al, and Si. The growth kinetics of the LaAlO3 film was described by three processes: (1) formation of the SiOx layer at the early stage whose thickness saturates rapidly at about 13Å; (2) formation of the LaxAlyOzSi layer by the out diffusion of Si and the inner diffusion of La, Al (mostly La). This stage continues as the film grows (3) In the deposition process of LaAlO3, the distributions of La and Al in the LaAlO3 layer change from inhomogeneous to homogeneous.