Three-dimensional differential inductor with vertical winding

A method comprising:

• forming a metal stack on a semiconductor chip, wherein the metal stack comprises a plurality of metal layers, wherein the semiconductor chip comprising a substrate and an integrated circuit;
• forming a first planar spiral differential inductor in the metal stack, wherein the first planar spiral differential inductor comprises at least two metal layers of the metal stack.
• wherein the semiconductor chip defines a semiconductor plane having a semiconductor plane normal vector and the first planar spiral differential inductor defines a first differential inductor plane having a first differential inductor plane normal vector, wherein an angle between the semiconductor plane normal vector and the first differential inductor plane normal vector is between 1 and 90 degrees.

A semiconductor device comprising a planar spiral differential inductor in a metal stack, and made by a process, the process comprising:

• forming the metal stack on a semiconductor chip, wherein the metal stack comprises a plurality of metal layers, wherein the semiconductor chip comprising a substrate and an integrated circuit;
• and
• forming the planar spiral differential inductor in the metal stack, wherein the planar spiral differential inductor comprises at least two metal layers of the metal stack, wherein the semiconductor chip defines a semiconductor plane having a semiconductor plane normal vector and the first planar spiral differential inductor defines a first planar spiral differential inductor plane having a first differential inductor plane normal vector, wherein an angle between the semiconductor plane normal vector and the first planar spiral differential inductor plane normal vector is between 1 and 90 degrees.