Roy, S,Connell, A,Ludwig, M,Wang, N,O'Donnell, T,Brunet, M,McCloskey, P,OMathuna, C,Barman, A,Hicken, RJ

2005

April

Journal of Magnetism and Magnetic Materials

Pulse reverse plating for integrated magnetics on Si

Validated

()

microtransformer cores pulse reverse plating diffusion limited aggregation GRANULAR FILMS ELECTRODEPOSITS CORE

290

1524

1527

Thin film microtransformers have been fabricated on silicon with Ni45Fe55 as a core material. Fractal/dendritic growths are observed in the patterned cores in DC electroplating due to the enhancement of localized current density at defect/nucleation sites. A 'pulser' device was made in house to produce forward and reverse current of the required amplitude for a particular duration. The combination of a low amplitude long (millisecond) forward pulse and a short (microsecond) high-amplitude reverse pulse gave dendrite-free plated cores with a uniform thickness and alloy composition over a 3D topology of a microrough substrate surface. Finally, we characterized the material in situ by small signal electrical measurements, and with MOKE hysteresis loops measured on a complete device. © 2004 Elsevier B.V. All rights reserved.

10.1016/j.jmmm.2004.11.566