Material characterisation of electroplated nickel structures for microsystem technology

Nickel layers 15 mum thick were pulse plated from a commercially available sulphamate-based electrolyte on an evaporated gold substrate or an electroplated copper substrate. The gold layer showed a (111) crystalline preference orientation, whereas for the copper layer no texture was observed. The deposited nickel layer showed a (110) texture at a low mean current density of 2.5 mA/cm(2), whereas at a high mean current density of 20 mA/cm(2) a (100) texture was observed. The structure analysis was supported by SEM pictures of polished and etched cross sections. For the nickel layers deposited on the gold substrate the structure changed from a columnar structure at low mean current densities to a granular structure at high mean current densities, whereas for the layers deposited on copper a granular structure was observed even at low mean current densities. (C) 2001 Elsevier Science Ltd. All rights reserved.