Permalloy electroplating through photoresist molds

Electrodeposited Ni80Fe20 magnetic films are used in storage devices and ar e usually used for MEMS. In this paper, we present some fundamental results concerning the influence of electrodeposition conditions on the films char acteristics. In the first step, permalloy electrodeposition has been studie d on copper evaporated films without resist patterns. The growth rate varie s Linearly as function of the current density (typically 120 nm min(-1) for 10 mA cm(-2)). The variation of the alloy composition with deposition para meters is consistent with the so-called anomalous deposition effect, i.e., a preferential deposition of iron. The composition is the same for films wi th thickness in the range 0.6-20 mu m and the Fe concentration decreases wi th current density. An alloy Ni80Fe20 with a density close to the bulk valu e is obtained for a current density of 14.5 mA cm(-2). Characterization of magnetic properties with a vibrating magnetometer shows that good propertie s can be obtained (coercivity = 0.35 Oe for a thickness of 600 nm). These r esults are applied to the patterning of permalloy by electrodeposition thro ugh photoresist molds. (C) 1999 Elsevier Science S.A. All rights reserved.