Magnetic core, inductor, and method for fabricating the magnetic core

Patent metadata

Field	Value
Publication number	US-9893141-B2
Application number	US-201514632519-A
Country	US
Kind code	B2
Filing date	Feb 26, 2015
Priority date	Feb 26, 2015
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

A magnetic core includes a center section having a substantially uniform thickness, and an edge section connected to and surrounding the center section. The edge section includes a bottom portion and a top portion disposed on the bottom portion, in which the bottom portion has a gradual side surface since the top portion has a steep side surface. The profile of the magnetic core can be more rectangular thereby providing better inductor performance.

First claim

What is claimed is:

1. A semiconductor device, comprising:
a semiconductor substrate; and
a magnetic core over the semiconductor substrate, the magnetic core comprising:
a center section having a substantially uniform thickness; and
an edge section connected to and surrounding the center section, the edge section comprising a bottom portion and a top portion disposed on the bottom portion, wherein the bottom portion has an inclined side surface, and the top portion has a curve side surface.

2. The semiconductor device of claim 1 , wherein a sum of a thickness of the bottom portion and a thickness of the top portion is substantially equal to the thickness of the center section.

3. The semiconductor device of claim 2 , wherein a ratio of the thickness of the bottom portion to the thickness of the top portion is in a range from about 2/3 to about 3/2.

4. The semiconductor device of claim 1 , wherein a width of the bottom portion extended from the center section is greater than a width of the top portion.

5. The semiconductor device of claim 1 , further comprising a middle portion disposed between the bottom portion and the top portion, wherein the middle portion has a steep side surface.

6. The semiconductor device of claim 5 , wherein the middle portion has a curve side surface.

7. A semiconductor device, comprising:
a substrate;
a bottom conductive layer disposed on the substrate;
a bottom dielectric layer formed on the bottom conductive layer;
a magnetic core formed on the bottom dielectric layer, the magnetic core comprising:
a center section having a substantially uniform thickness; and
an edge section connected to and surrounding the center section, the edge section comprising a bottom portion and a top portion disposed on the bottom portion, wherein the bottom portion is between the top portion and the substrate and is wider than the top portion;
a top dielectric layer formed on the magnetic core; and
a top conductive layer formed on the top dielectric layer.

8. The semiconductor device of claim 7 , wherein the bottom conductive layer and the top conductive layer form a winding wire wound on the magnetic core.

9. The semiconductor device of claim 7 , wherein the bottom portion has an inclined side surface, and the top portion has a curve side surface.

10. The semiconductor device of claim 7 , further comprising a middle portion disposed between the bottom portion and the top portion, wherein a side surface of the middle portion is steeper than a side surface of the bottom portion.

11. The semiconductor device of claim 7 , wherein the magnetic core is made of cobalt zirconium tantalum (CZT), nickel iron (NiFe), or iron nitride (FeN).

12. The semiconductor device of claim 10 , wherein the bottom portion has an inclined side surface, the middle portion has a curve surface, and the top portion has a curve surface.

13. The semiconductor device of claim 7 , wherein the bottom conductive layer and the top conductive layer are made of W, Co, Al, or Cu.

14. The semiconductor device of claim 7 , wherein the bottom dielectric layer and the top dielectric layer are made of silicon nitride, silicon carbide, nitrogen-doped silicon carbide, silicon oxynitride, oxygen-doped silicon carbide, or silicon oxide.

15. The semiconductor device of claim 7 , wherein the edge section comprises an anisotropic etched surface.

16. The semiconductor device of claim 7 , wherein a sum of a thickness of the bottom portion and a thickness of the top portion is substantially equal to the thickness of the center section.

17. The semiconductor device of claim 7 , wherein the magnetic core is not in a shape of triangle.

18. The semiconductor device of claim 7 , wherein the bottom portion is wider than the top portion.

19. A semiconductor device, comprising:
a semiconductor substrate; and
a magnetic core over the semiconductor substrate, the magnetic core comprising:
a center section having a substantially uniform thickness; and
an edge section connected to and surrounding the center section, wherein a side surface of the edge section has at least two different slopes.

20. The semiconductor device of claim 19 , wherein the center section and the edge section comprise a magnetic material.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Su Yen Shuo
• Kuo Chun Tsung
• Lu Jiech Fun

Classifications

• H01F17/0033

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

• H01F41/046 Primary

  structurally combined with ferromagnetic material · CPC title

• H01F3/02

  made from sheets · CPC title

• H01F27/2804

  Printed windings · CPC title

• H01L28/10 Primary

  Electricity · mapped topic