Method for forming a planar, closed loop magnetic structure

Patent metadata

Field	Value
Publication number	US-10600566-B2
Application number	US-201615292625-A
Country	US
Kind code	B2
Filing date	Oct 13, 2016
Priority date	Oct 13, 2016
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

A planar magnetic structure includes a closed loop structure having a plurality of core segments divided into at least two sets. A coil is formed about one or more core segments. A first antiferromagnetic layer is formed on a first set of core segments, and a second antiferromagnetic layer is formed on a second set of core segments. The first and second antiferromagnetic layers include different blocking temperatures and have an easy axis pinning a magnetic moment in two different directions, wherein when current flows through the coil, the magnetic moments rotate to form a closed magnetic loop in the closed loop structure.

First claim

What is claimed is:

1. A method for forming a planar, closed loop magnetic structure, comprising:
forming a first antiferromagnetic layer at a first blocking temperature for a closed magnetic loop to define a first pin direction for first magnetic moments;
forming a second antiferromagnetic layer at a second blocking temperature lower than the first blocking temperature for the closed magnetic loop to define a second pin direction different from the first pin direction for second magnetic moments; and
forming a coil around at least one core segment of the closed magnetic loop such that when the coil is energized the first and second magnetic moments rotate to follow a contour of the closed magnetic loop.

2. The method as recited in claim 1 , wherein the first and second pin directions are orthogonal to one another.

3. The method as recited in claim 1 , wherein forming the coil includes forming a single coil wound about at least two core segments.

4. The method as recited in claim 1 , wherein forming the coil includes forming two separate coils wound about two core segments to form coupled inductors.

5. The method as recited in claim 1 , wherein the first and second antiferromagnetic layers are formed in contact with ferromagnetic material that forms a core of the closed magnetic loop.

6. The method as recited in claim 1 , wherein the closed magnetic loop includes uniaxial anisotropy in each core segment and includes a high permeability direction around the closed magnetic loop when the coil is energized.

7. The method as recited in claim 1 , wherein the closed magnetic loop includes four sides with opposite sides including a same antiferromagnetic material.

8. The method as recited in claim 1 , wherein the closed magnetic loop is formed on a substrate and the coil is formed using vias and metal lines formed by semiconductor patterning processes.

9. A method for forming a planar, closed loop magnetic structure, comprising:
forming a planar, closed loop ferromagnetic core having four sides;
patterning a first antiferromagnetic layer on two opposing sides of the ferromagnetic core;
annealing the first antiferromagnetic layer at a first blocking temperature to define a first pin direction for first magnetic moments;
patterning a second antiferromagnetic layer on two other opposing sides of the ferromagnetic core;
annealing the second antiferromagnetic layer at a second blocking temperature, which is lower than the first blocking temperature to define a second pin direction for second magnetic moments; and
forming a coil around at least one core segment of the closed loop ferromagnetic core such that when the coil is energized the first and second magnetic moments rotate to follow a contour of the closed loop ferromagnetic core.

10. The method as recited in claim 9 , wherein forming the coil includes forming a single coil wound about at least two core segments.

11. The method as recited in claim 9 , wherein forming the coil includes forming two separate coils wound about two core segments to form coupled inductors.

12. The method as recited in claim 11 , wherein the closed magnetic loop includes uniaxial anisotropy in each core segment and includes a high permeability direction around the closed loop ferromagnetic core when the coil is energized.

Assignees

• IBM

Inventors

• Hu Guohan
• Wang Naigang

Classifications

• H01F17/0033

  with the coil helically wound around a magnetic core · CPC title

• H01F2003/106

  Magnetic circuits using combinations of different magnetic materials · CPC title

• H01F41/046 Primary

  structurally combined with ferromagnetic material · CPC title

• H01F3/10

  Composite arrangements of magnetic circuits · CPC title

• H01F27/2804

  Printed windings · CPC title