Thick Electroplated Co-Rich Co-Pt Micromagnet Arrays for Magnetic MEMS

Photolithographically-defined patterned arrays of Co-rich Co-Pt permanent magnets with thicknesses up to 10 mu m were fabricated by aqueous electrodeposition. These micromagnets exhibited strong perpendicular magnetic performance while being deposited at low temperatures (65^deg C) and without the need for post-deposition annealing. Co-Pt magnet arrays grown 10-mu m thick on textured Cu (111) seed layers on Si (110) substrates exhibited coercivities of 330 kA/m (4.1 kOe) and energy products 69 kJ/m³. Additionally, magnets deposited 8-mu m thick on untextured Cu seed layers on standard Si (100) substrates exhibited coercivities up to 260 kA/m (3.3 kOe) and energy products up to 27 kJ/m³. The high magnetic performance and process integrability of these permanent magnet arrays make them well suited for the development of magnetic microelectromechanical systems (MEMS).