Micromolding of NiFe and Ni Thick Films for 3D Integration of MEMS

Electrodeposition process was studied in order to obtain uniformly thick magnetic films which could be incorporated in magnetic microsensors and actuators. Ni and NiFe patterns of different dimensions were deposited by micromolding on a Cu/Ti seed layer sputtered on SiO2/Si (for NiFe) and glass (for Ni). In the case of NiFe deposit, a linear deposition rate was calculated by measuring the deposit thickness using mechanical profilometry. The optimum pattern composition for the fabrication of magnetic microdevices was 80 at.% of Ni, that was found by comparing the magnetic properties of the deposits obtained from different conditions. The deposits structure was also characterized. All the parameters were studied as a function of the current density so that by controlling the electrodeposition conditions the characteristics of the deposits could be controlled. NiFe films were integrated in multilayered magneto-impedance sensors. They present good adherence of the layers even after performing annealing at both 300°C and 500°C and sensor sensitivity reaches 1%/Oe.