Three-dimensional inductors 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 inductor in the metal stack, wherein the first planar spiral 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 inductor defines a first inductor plane having a first inductor plane normal vector, wherein an angle between the semiconductor plane normal vector and the first inductor plane normal vector is between 1 and 90 degrees.

A semiconductor device comprising a planar spiral 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 inductor in the metal stack, wherein the planar spiral 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 inductor defines a first inductor plane having a first inductor plane normal vector, wherein an angle between the semiconductor plane normal vector and the first inductor plane normal vector is between 1 and 90 degrees.