Abnormally large Ni grains epitaxially grown by electrodeposition on Cu substrate

This study investigates formation of abnormally large grains in a Ni layer electrodeposited using additive-free Watts bath. The Ni electrodeposited layer had bimodal structure with abnormally large grains and fine grains. Surface morphology of the fine grains was relatively heterogeneous and composed by fine crystals with quadrangular pyramid shape, while surface of the abnormally large grain was uniform. Electron backscatter diffraction analysis was conducted for the surface, the cross section of the layer, and after polishing the Ni electrodeposited layer. Shape and crystallographic orientation of the abnormally large grains are consistent with those of the corresponding grains on surface of the Cu substrate. The large epitaxial growth occurred on the substrate only with near [100] orientation, while abnormally large grains could not be formed the substrate with [111] or [110] orientation. The abnormally large grain formation is caused by epitaxial growth on the substrate with the particular crystal orientation.

► Formation of abnormally large grains in an electrodeposited Ni layers.
► Large Ni epitaxial growth only on Cu substrate with near [100] orientation.
► Large grains could not form on Cu substrate with [111] or [110] orientation.