Patent ID: 8877030

Claim:
A magnetic film plating apparatus comprising: a plating tank for holding therein a plating solution; an anode vertically disposed in the plating tank at a position to be immersed in the plating solution; a substrate holder for holding a substrate and positioning the substrate opposite the anode; and a cylindrical magnetic field generator comprised of an electromagnet and disposed around the plating tank, wherein the electromagnet comprises a cylindrical yoke disposed around the plating tank and a coil extending circumferentially on an inner circumferential surface of the cylindrical yoke, and is configured to generate a vertically directed magnetic field around and parallel to the substrate held by the substrate holder and positioned opposite the anode, wherein a center of the cylindrical yoke is located at the same height of the substrate; and wherein the coil comprises an upper coil, a middle coil, and a lower coil which are disposed vertically and the cylindrical magnetic field generator is configured to pass independent electric currents to the upper coil, the middle coil, and the lower coil to generate vertical magnetic fields of different strengths, the vertical position of the middle coil being equal to the vertical position of the substrate.