Structural and optical characterization of amorphous As40S60 and As40Se60 films prepared by plasma-enhanced chemical vapor deposition

摘要

Amorphous chalcogenide films of chemical compositions As40S60 and As40Se60 have been prepared by plasma-enhanced chemical vapor deposition. An improved optical characterization method suitable for non-uniform thin films, which also takes into consideration the weak absorption in the substrate, has successfully been applied. The values of the average thickness and thickness variation, (d) over bar and Deltad, respectively, were crossed-checked with those measured by use of a surface-profiling stylus instrument, and differences between the directly measured and the optically calculated values were, in all cases, less than 2%. A comparison between the structural and optical properties of these PECVD films, and those of the same chemical composition prepared by thermal evaporation, is systematically made in this paper. (C) 2004 Published by Elsevier B.V.