Fabrication of NdFeB microstructures using a silicon molding technique for NdFeB/Ta multilayered films and NdFeB magnetic powder

The silicon molding technique is described for patterning of NdFeB/Ta multilayered magnetic films and NdFeB magnetic powder at the micron scale. Silicon trenches are seamlessly filled by 12-μm-thick NdFeB/Ta multilayered magnetic films with a magnetic retentivity of 1.3 T. The topography image and magnetic field distribution image are measured using an atomic force microscope and a magnetic force microscope, respectively. Using a silicon molding technique complemented by a lift-off process, NdFeB magnetic powder is utilized to fabricate magnetic microstructures. Silicon trenches as narrow as 20 μm are filled by a mixture of magnetic powder and wax powder. The B–H hysteresis loop of the patterned magnetic powder is characterized using a vibrating sample magnetometer, which shows a magnetic retentivity of approximately 0.37 T. ► We demonstrate the fabrication of micro-magnets using silicon molding processes. ► NdFeB/Ta films are well filled in silicon trenches with a thickness of 12 μm. ► The 12-μm-thick NdFeB/Ta magnetic film shows a retentivity of 1.3 T. ► Magnetic structures as narrow as 20 μm are fabricated using NdFeB magnetic powder. ► VSM measurement shows a retentivity of 0.37 T for patterned NdFeB magnetic powder.