Device having an in-substrate inductor and method for making the inductor

A device including an inductor, the inductor comprising:

• a substrate having a first planar surface and a second planar surface opposite the first planar surface;
• a first row of vias disposed through the substrate and filled with a conductive metal, wherein the first row of vias is aligned along a first longitudinal axis;
• a second row of vias disposed through the substrate and filled with the conductive metal, wherein the second row of vias is laterally displaced from the first row of vias and aligned along a second longitudinal axis parallel to the first longitudinal axis, wherein vias of the first row of vias and corresponding vias of the second row of vias are disposed as respective opposed pairs of vias;
• a via structure disposed through the substrate and extending parallel to both the first row of vias and the second row of vias, the via structure being filled with a magnetic material to form a magnetic core of the inductor that is electrically insulated from the conductive metal filling the first row of vias and the conductive metal filling the second row of vias, wherein the via structure comprises a longitudinal trench disposed between the first row of vias and the second row of vias, and a plurality of transverse trenches disposed between the respective opposed pairs of vias;
• a first patterned metallization layer exterior to the first planar surface disposed perpendicularly between and interconnecting the conductive metal of the respective opposed pairs of vias;
• and
• a second patterned metallization layer exterior to the second planar surface forming diagonal interconnections between the conductive metal of the first row of vias and the conductive metal of the second row of vias, wherein the diagonal interconnections are disposed to overlie corresponding transverse trenches of the plurality of transverse trenches;
• wherein the first patterned metallization layer, the second patterned metallization layer, the conductive metal filling the first row of vias, and conductive metal filling the second row of vias form a winding of the inductor about the magnetic core.

A method of fabricating an inductor, comprising:

• forming a plurality of vias disposed through a substrate and filled with a conductive metal, wherein the plurality of vias comprises a first row of vias aligned along a first longitudinal axis and a second row of vias aligned along a second longitudinal axis parallel to the first longitudinal axis, and wherein vias of the first row of vias and corresponding vias of the second row of vias are disposed as respective opposed pairs of vias;
• forming a via structure disposed through the substrate and filled with a magnetic material, the via structure extending between the plurality of vias and forming a magnetic core of the inductor, wherein the via structure comprises a longitudinal trench disposed between the first row of vias and the second row of vias and extends parallel to both the first row of vias and the second row of vias, and a plurality of transverse trenches disposed between opposed pairs of the plurality of vias;
• and
• forming one or more patterned metallization layers interconnecting the conductive metal of the plurality of vias, wherein the one or more patterned metallization layers comprise a first patterned metallization layer disposed perpendicularly between and interconnecting the conductive metal of the respective opposed pairs of vias, and a second patterned metallization layer forming diagonal interconnections between the conductive metal of vias of the first row of vias and the conductive metal of vias of the second row of vias, wherein the diagonal interconnections are disposed to overlie corresponding transverse trenches of the plurality of transverse trenches;
• wherein the one or more patterned metallization layers and the conductive metal filling the plurality of vias form a winding of the inductor about the magnetic core.

A method of fabricating an inductor, comprising:

• forming a first row of vias through a substrate, wherein the first row of vias is aligned along a first longitudinal axis;
• forming a second row of vias through the substrate, wherein the second row of vias is laterally displaced from the first row of vias and aligned along a second longitudinal axis parallel to the first longitudinal axis, wherein vias of the first row of vias and corresponding vias of the second row of vias are disposed as respective opposed pairs of vias;
• forming a via structure through the substrate extending parallel to both the first row of vias and the second row of vias, wherein the via structure comprises a longitudinal trench disposed between the first row of vias and the second row of vias, and a plurality of transverse trenches disposed between the opposed pairs of vias;
• filling the first row of vias and the second row of vias with a conductive metal;
• filling the via structure with a magnetic material;
• forming a first patterned metallization layer exterior to a first planar surface of the substrate, wherein the first patterned metallization layer is disposed perpendicularly between and electrically interconnects the conductive metal of the respective opposed pairs of vias;
• and
• forming a second patterned metallization layer exterior to a second planar surface of the substrate opposite the first planar surface, wherein the second patterned metallization layer forms diagonal interconnections between the conductive metal of vias of the first row of vias and the conductive metal of vias of the second row of vias, and wherein the diagonal interconnections are disposed to overlie corresponding transverse trenches of the plurality of transverse trenches;
• wherein the first patterned metallization layer, the second patterned metallization layer, the conductive metal filling the first row of vias, and conductive metal filling the second row of vias form a winding of the inductor about a magnetic core formed by the magnetic material in the via structure.