Epitaxial growth and microstructure of RF sputtered CuAu films

Abstract

The epitaxial growth of equiatomic CuAu films using rf sputtering was investigated. The lowest epitaxial temperature was found to be 220 +− 10 °C for deposition rates ranging from 40 to 170 Å/min. The chemical composition of the sputtered films was found to be the same as that of the target. The initial stages of epitaxial growth of the alloy films follow the typical classical behavior for evaporated films: the nucleation stage, the coalescence stage, the channel stage, and the continuous film. The microstructure of the films was studied by electron transmission and diffraction microscopy. The phases present in the alloy films change as the substrate temperature varies. Extra reflections were identified as {111} twin spots and double diffraction spots which originated from {101} twins in the ordered phase. Other internal defects were also studied and are reported.