An Ex-Situ Study of Epitaxial Growth of Nickle on Copper Substrate in Electrodeposition

Abstract

An ex-situ method was used to study the anisotropy of the epitaxial growth of electrodeposited nickel on polycrystalline copper substrate. The orientation of the substrate grain was characterized by electron backscatter diffraction (EBSD) technique prior to the electrodeposition. Nickel films of approximately 1 um thick were then deposited onto the polished substrates in a sulfamate bath under various current densities. The orientation of the Ni deposits located in the prior-analyzed area was characterized again by EBSD to reveal the orientation relationship between the deposit and the substrate. EBSD analysis was also carried out for thick deposits from a transverse direction to clarify the growth behavior and microstructural evolution of the deposits on grains of different orientations. Results indicate that epitaxial growth is allowed solely on grains having an orientation of <100>//ND at a low current density. On the contrary, the nickel deposits grow epitaxially on almost all grains no matter the orientation as the current density is in a range of 1-10 A/dm2. However, the surface topology of the deposits on substrate grains of different orientations is very different. Accordingly, the microstructure evolution of the <100>//ND and non-<100>//ND deposits are very different and detail will be presented.