Thin-film processing electromagnet with modified core for producing low-skew magnetic orientation

A thin-film processing electromagnet for low-skew magnetic orientation of a magnetic material layer on a substrate comprising:

• a plate-shaped core containing magnetically permeable material and having front and back surfaces joined by a periphery;
• electrically conductive windings wrapped around a region of said plate-shaped core forming at least one electromagnetic coil for producing a substantially uniaxial magnetic field adjacent to said front surface of the plate-shaped core for orienting the magnetic material layer on the substrate;
• said magnetically permeable material of the plate-shaped core having an effective magnetic mass that varies within the region wrapped by said electrically conductive windings from a center toward the periphery of the plate-shaped core for reducing skew angle of the substantially uniaxial magnetic field adjacent to the front surface of the plate-shaped core over the entire substrate surface area;
• said effective magnetic mass variation involving a reduction in the mass of magnetically permeable material near the center of the core with respect to the mass of magnetically permeable material near the periphery of the core;
• cooling passages being formed in said plate-shaped core;
• said cooling passages intersecting a cavity that contributes to said effective magnetic mass variation;
• said periphery of the plate-shaped core having a plurality of sides separated by intersection corners, and said cooling passages entering and leaving said plate-shaped core through at least a subset of said corners;
• and
• further comprising corner posts located at said corners of the plate-shaped core for providing entry and exit ports for said cooling passages in said plate-shaped core.

A thin-film processing electromagnet for low-skew magnetic orientation of a magnetic material layer on a substrate comprising:

• a plate-shaped core containing magnetically permeable material and having front and back surfaces joined by a periphery;
• electrically conductive windings wrapped around a region of said plate-shaped core forming at least one electromagnetic coil for producing a substantially uniaxial magnetic field adjacent to said front surface of the plate-shaped core for orienting the magnetic material layer on the substrate;
• said magnetically permeable material of the plate-shaped core having an effective magnetic mass that varies within the region wrapped by said electrically conductive windings from a center toward the periphery of the plate-shaped core for reducing skew angle of the substantially uniaxial magnetic field adjacent to the front surface of the plate-shaped core over the entire substrate surface area;
• said effective magnetic mass variation involving a reduction in the mass of magnetically permeable material near the center of the core with respect to the mass of magnetically permeable material near the periphery of the core;
• and
• wherein said substrate resides in a physical-vapor deposition system.

A thin-film processing electromagnet for low-skew magnetic orientation of a magnetic material layer on a substrate comprising:

• a plate-shaped core containing magnetically permeable material and having front and back surfaces joined by a periphery;
• electrically conductive windings wrapped around a region of said plate-shaped core forming at least one electromagnetic coil for producing a substantially uniaxial magnetic field adjacent to said front surface of the plate-shaped core for orienting the magnetic material layer on the substrate;
• said magnetically permeable material of the plate-shaped core having an effective magnetic mass that varies within the region wrapped by said electrically conductive windings from a center toward the periphery of the plate-shaped core for reducing skew angle of the substantially uniaxial magnetic field adjacent to the front surface of the plate-shaped core over the entire substrate surface area;
• said effective magnetic mass variation involving a reduction in the mass of magnetically permeable material near the center of the core with respect to the mass of magnetically permeable material near the periphery of the core;
• and
• wherein said substrate resides in a magnetic thermal annealing system.

A thin-film processing electromagnet mounted adjacent to an evacuated processing space of a processing chamber containing a substrate having a surface and producing a uniaxial magnetic field on the surface of the substrate comprising a plate-shaped core and an electromagnetic coil wrapped between two winding planes of said plate-shaped core;

• said plate-shaped core exhibiting as a function core dimension an effective magnetic mass between said winding planes that varies along an axis parallel to said winding planes in a pattern that reduces skew of the uniaxial magnetic field;
• said effective magnetic mass varying between a center and a periphery of said plate-shaped core;
• said effective magnetic mass being reduced at said center of the plate-shaped core with respect to said periphery of the plate-shaped core;
• and said plate-shaped core together with said electromagnetic coil being mounted adjacent to the evacuated processing space of the processing chamber and positioning the uniaxial magnetic field within the processing space in an orientation parallel to the surface of the substrate.