Hard Magnetic Materials for MEMS Applications

Micro-magnets of thickness in the range 1-500 mu m have many potential applications in micro-electro-mechanical-systems (MEMS) because of favorable downscaling laws and their unique ability to produce long range bi-directional forces. The advantages and disadvantages of a number of "top-down" routes, which use bulk processed precursors (magnets or magnetic powders), to produce mu-magnets of thickness in the range 10-500 mu m will be discussed. Progress in the fabrication and patterning of thick film magnets (1-100 mu m) using "bottom-up" deposition techniques will be reviewed. In particular, recent results concerning high-rate triode sputtering and micro-patterning of high-performance NdFeB and SmCo films will be presented.