Method for fabricating magnetic core

• US 10,461,145 B2
• Filed: 01/25/2018
• Issued: 10/29/2019
• Est. Priority Date: 02/26/2015
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Su, Yen-Shuo, Kuo, Chun-Tsung, Lu, Jiech-Fun
• Primary Examiner(s): Campbell, Shaun M
• Application Number:
  US15/880,289
• Publication Number:
  US 20180166527A1
• Time in Patent Office: 642 Days
• CPC Class Codes: H01F 17/0033 with the coil helically wound around a magnetic core
• CPC Class Codes: H01F 41/046 structurally combined with ferromagnetic material
• CPC Class Codes: H01L 28/10 Inductors

Abstract

A method for fabricating a magnetic core includes depositing a magnetic layer on a dielectric layer, forming a first photoresist layer on the magnetic layer and patterning the first photoresist layer, etching the magnetic layer through the patterned first photoresist layer, in which a first section of the magnetic layer exposed by the first photoresist layer remains on the dielectric layer after the magnetic layer is etched, removing the patterned first photoresist layer, forming a second photoresist layer on the magnetic layer and patterning the second photoresist layer, etching the magnetic layer through the patterned second photoresist layer, and removing the second photoresist layer.

Claims

1. A method for fabricating a magnetic core, comprising:

depositing a magnetic layer on a dielectric layer;

forming a first photoresist layer on the magnetic layer and patterning the first photoresist layer;

etching the magnetic layer through the patterned first photoresist layer, wherein a first section of the magnetic layer exposed by the patterned first photoresist layer remains on the dielectric layer after etching the magnetic layer;

removing the patterned first photoresist layer;

forming a second photoresist layer on the magnetic layer and patterning the second photoresist layer such that the patterned second photoresist layer has a curve portion;

etching the magnetic layer through the patterned second photoresist layer such that the curve portion of the patterned second photoresist layer suspends without support above the magnetic layer; and

removing the patterned second photoresist layer.

2. The method of claim 1, wherein the first photoresist layer and the second photoresist layer are patterned using the same mask.

3. The method of claim 1, wherein a portion of the patterned second photoresist layer covering a second section of the magnetic layer is larger than a portion of the patterned first photoresist layer covering the second section of the magnetic layer.

4. The method of claim 1, wherein the first section of the magnetic layer exposed by the patterned second photoresist layer is removed from the dielectric layer after etching the magnetic layer through the patterned second photoresist layer.

5. The method of claim 1, wherein the first section of the magnetic layer exposed by the patterned second photoresist layer remains on the dielectric layer after etching the magnetic layer through the patterned second photoresist layer.

6. The method of claim 5, further comprising:

forming a third photoresist layer on the magnetic layer and patterning the third photoresist layer;

etching the magnetic layer through the patterned third photoresist layer, wherein the first section of the magnetic layer exposed by the patterned third photoresist layer is removed from the dielectric layer after etching the magnetic layer through the patterned third photoresist layer; and

removing the patterned third photoresist layer.

7. The method of claim 6, wherein the first photoresist layer, the second photoresist layer, and the third photoresist layer are patterned using the same mask.

8. The method of claim 1, wherein etching the magnetic layer through the patterned first photoresist layer is performed using a wet etching process.

9. A method for fabricating a magnetic core, comprising:

depositing a magnetic layer over a dielectric layer;

forming a first patterned photoresist layer over the magnetic layer, wherein a first section of the magnetic layer is exposed by the first patterned photoresist layer, and a second section of the magnetic layer is covered by the first patterned photoresist layer;

etching the first section of the magnetic layer through the first patterned photoresist layer;

forming a second patterned photoresist layer over the magnetic layer, wherein the first section of the magnetic layer is exposed by the second patterned photoresist layer, and the second section of the magnetic layer is covered by the second patterned photoresist layer; and

etching again the first section of the magnetic layer through the second patterned photoresist layer.

10. The method of claim 9, further comprising removing the first patterned photoresist layer prior to etching the first section of the magnetic layer through the second patterned photoresist layer.

11. The method of claim 9, wherein the first section of the magnetic layer is removed from the dielectric layer after etching the first section of the magnetic layer through the second patterned photoresist layer.

12. The method of claim 9, wherein the first section of the magnetic layer remains on the dielectric layer after etching the first section of the magnetic layer through the second patterned photoresist layer.

13. The method of claim 9, wherein etching the magnetic layer through the first patterned photoresist layer is performed using a wet etching process.

14. The method of claim 9, wherein etching the first section of the magnetic layer through the second patterned photoresist layer is performed using a wet etching process.

15. The method of claim 9, wherein the first patterned photoresist layer and the second patterned photoresist layer are patterned using the same mask.

16. The method of claim 9, wherein a portion of the second patterned photoresist layer covering the second section of the magnetic layer is larger than a portion of the first patterned photoresist layer covering the second section of the magnetic layer.

17. A method for fabricating a magnetic core, comprising:

depositing a magnetic layer over a dielectric layer;

etching the magnetic layer, such that the magnetic layer having a pair of first sections and a second section between the first sections, and the second section is thicker than the first sections;

forming a first patterned photoresist layer over the second section, wherein the first sections are exposed by the first patterned photoresist layer;

etching the first sections through the first patterned photoresist layer such that at least one of the first sections has a convex sidewall; and

removing the first patterned photoresist layer.

18. The method of claim 17, wherein the first sections are removed from the dielectric layer after etching the first sections through the first patterned photoresist layer.

19. The method of claim 17, wherein the first sections remain on the dielectric layer after etching the first sections through the first patterned photoresist layer.

20. The method of claim 19, further comprising:

forming a second patterned photoresist layer over the second section, wherein the first sections are exposed by the second patterned photoresist layer; and

etching the first sections through the second patterned photoresist layer.