Microstructures of soft-magnetic cobalt-molybdenum alloy obtained by electrodeposition on seed layer/silicon substrates

Cobalt molybdenum alloy containing similar to10% molybdenum, which has promising applications in magnetic devices, was deposited on silicon-based substrates. A solution containing 0.2 mol dm(-3) C6H5Na3O7 + 0.3 mol dm(-3) CoSO4 + 0.012 mol dm(-3) Na2MoO4 at pH = 4.0 and 25 degreesC was used to prepare Co-Mo coatings, which showed a soft-magnetic response. A constant deposition rate of 7.7 mum h(-1) was achieved under stirring. White-light interferometry and AFM techniques were used to measure the thickness of Co-Mo coatings, with identical results. White-light interferometry also revealed smooth surfaces. Deposition was highly selective on mask devices and deposits were crack-free up to similar to7 mum. Vertical walls and well-defined profiles of the coatings were obtained. At higher thickness cracks appeared and the Co-Mo layers detached. The stress was reduced by increasing the temperature and adding saccharine to the bath. (C) 2004 Elsevier B.V. All rights reserved.