In situ fixed angle X-ray reflectivity study of sputter-deposited amorphous LaNiO3 thin film on Si substrate

摘要

A fixed angle X-ray reflectivity measurement was used to measure in situ the surface roughness, density and thickness of an amorphous LaNiO3, thin him during the magnetron sputtering deposition. Unlike the traditional 2 theta/theta reflectivity measurement, in this experiment, the sample and detector positions are held at fixed angles. An oscillating reflectivity intensity as a function of time can be observed as the film thickness grows. The oscillation period provides the information of deposition rate, and the oscillation amplitude provides the information on him density and interface roughness as functions of film thicknesses. During the early stage of deposition, the low and increasing reflected intensity might indicate an island growth mechanism or an ion peening effect taking place. The reflected intensity increases up to a thickness of 40 Angstrom indicating that the growing islands are totally coalesced at this thickness. As the thin film continuously grows, the interface roughness follows a diffusion model. However, the surface of the thin film remains a sharp one. (C) 1998 Elsevier Science B.V. All rights reserved. [References: 21]