High performance hard magnetic NdFeB thick films for integration into micro-electro-mechanical systems

Abstract

5 μ m thick NdFeB films have been sputtered onto 100mm Si substrates using high rate sputtering (18μm∕h). Films were deposited at ⩽500°C and then annealed at 750°C for 10min. While films deposited at temperatures up to 450°C have equiaxed grains, the size of which decreases with increasing deposition temperature, the films deposited at 500°C have columnar grains. The out-of-plane remanent magnetization increases with deposition temperature, reaching a maximum value of 1.4T, while the coercivity remains constant at about 1.6T. The maximum energy product achieved (400kJ∕m3) is comparable to that of high-quality NdFeB sintered magnets.