Topography and residual stress analysis for Cu/Au/Co multilayered system

Abstract

Residual stresses, microstructure and the surface topography of a substrate play a crucial role in the optimization of any electrodeposition process. To address this significant but often neglected problem, a detailed research focused on investigation of residual stresses in a Cu polycrystalline substrate electrochemically covered by a thin Au layer and Co coating was conducted. Additionally, the evolution of the microstructure, crystallographic texture and surface topography for the substrate and deposited layers were characterized. While the standard X-ray diffraction method showed insignificant residual stress in the Cu substrate, the multireflection X-ray diffraction methodology allowed us to determine small compressive depth-dependent residual stresses in Cu, close to the interface, when thin Co coating was deposited. Those stresses relaxed for longer deposition time, i.e. for ticker Co coating. The character of the stress distribution and microstructural investigations suggest that the stresses were generated in the Co coating due to coalescence of deposited islands.