Microstructure and crystallographic characteristics of nanocrystalline copper prepared from acetate solutions by electrodeposition technique
(Electroplating and Metal Finishing Technology Division, Central Electrochemical Research Institute, Karaikudi-630 006, Tamil Nadu, India)
Abstract: Methane sulphonic acid is an alternative electrolyte for conventional sulphuric acid for copper deposition. The electrodeposition of copper from eco-friendly acetate-based electrolytes consisting of copper acetate, sodium acetate and methane sulphonic acid was dealt. Thamine hydrochloride (THC), saccharin and 4-amino-3-hydroxynaphthalene 1-suphonic acid were used as additives in depositing electrolytes. The cathode current efficiency was calculated using the Faraday’s law. Metal distrbution ratio of the solutions was determined using Haring-Blum cell. These additives impact the surface morphology of deposited copper films by downgrading, the grain size was analyzed by scanning electron microscopy (SEM) and X-ray diffiraction technique. XRD pattern acquired for electrodeposited copper film shows polycrystalline and face centered cubic structure (FCC). The crystal size of the copper film was calculated using the Debye-Scherrer’s equation. The crystal size revealed that deposits produced from additive containing electrolytes exhibited the lowest grain size. Texture coefficient analysis studies revealed that all copper film deposits are polycrystalline and the crystals are preferentially oriented and parallel to the surface. A uniform and pin-hole free surface morphology and grain refining were brought about by the additives.
Key words: acetate; copper electrodeposition; additives