Inductor structure with magnetic material

• US 9,048,128 B2
• Filed: 10/03/2013
• Issued: 06/02/2015
• Est. Priority Date: 10/03/2013
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Tseng, Yuan-Tai, Liu, Ming-Chyi, Chou, Chung-Yen, Tsai, Chia-Shiung
• Primary Examiner(s): DANG, PHUC T
• Application Number:
  US14/044,979
• Publication Number:
  US 20150097267A1
• Time in Patent Office: 607 Days
• Field of Search: 257/421, 257/531, 257/E29.323, 336/200
• US Class Current: 1/1
• CPC Class Codes: H01F 1/0306 Metals or alloys, e.g. LAVES phase alloys of the MgCu2-type H01F1/0304 takes precedence
• CPC Class Codes: H01F 17/0013 with stacked layers
• CPC Class Codes: H01F 17/0033 with the coil helically wound around a magnetic core
• CPC Class Codes: H01F 2017/0066 with a magnetic layer
• CPC Class Codes: H01F 2027/2809 on stacked layers
• CPC Class Codes: H01F 27/24 Magnetic cores
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 28/10 Inductors
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

Embodiments of mechanisms of forming an inductor structure are provided. The inductor structure includes a substrate and a first dielectric layer formed over the substrate. The inductor structure includes a first metal layer formed in the first dielectric layer and a second dielectric layer over the first metal layer. The inductor structure further includes a magnetic layer formed over the first dielectric layer, and the magnetic layer has a top surface, a bottom surface and sidewall surfaces between the top surface and the bottom surface, and the sidewall surfaces have at least two intersection points.

Claims

1. An inductor structure, comprising:

a substrate;

a first dielectric layer formed over the substrate;

a first metal layer formed in the first dielectric layer;

a second dielectric layer over the first metal layer;

a magnetic layer formed over the first dielectric layer, wherein the magnetic layer has a top surface, a bottom surface and sidewall surfaces between the top surface and the bottom surface, and the sidewall surfaces have at least two intersection points, and wherein the sidewall surfaces comprise a first pair of sidewall surfaces adjoin the bottom surface and a second pair of sidewall surfaces adjoin the first pair of sidewall surfaces, wherein

the first pair of sidewall surfaces are vertical to the bottom surface of the magnetic layer; and

the second pair of sidewall surfaces taper gradually toward the top surface of the magnetic layer.

2. The inductor structure as claimed in claim 1, wherein the sidewall surfaces comprises a first sidewall surface, a second sidewall surface and a third sidewall surface, the first sidewall surface is connected to top surface, and an angle between the first sidewall surface and the second sidewall surface is in a range about 30 degrees to about 85 degrees.

3. The inductor structure as claimed in claim 2, wherein the third sidewall surface is connected to the bottom surface, and an angle between the second sidewall surface and the third sidewall surface is in a range about 95 degrees to about 150 degrees.

4. The inductor structure as claimed in claim 1, wherein the sidewall surfaces comprises a first sidewall surface and a second sidewall surface, the first sidewall surface is connected to top surface, and an angle between the top surface and the first sidewall surface is in a range about 120 degrees to about 175 degrees.

5. The inductor structure as claimed in claim 4, wherein an angle between the first sidewall surface and the second sidewall surface is in a range about 95 degrees to about 150 degrees.

6. The inductor structure as claimed in claim 1, wherein the magnetic layer comprises cobalt (Co), zirconium (Zr), tantalum (Ta) and niobium (Nb), rhenium (Re), neodymium (Nd), praseodymium (Pr), or dysprosium (Dy) or combinations thereof.

7. The inductor structure as claimed in claim 1, wherein a spiral structure is made by the first metal layer, vias and a second metal layer.

8. The inductor structure as claimed in claim 7, wherein the magnetic layer is surrounded by the spiral structure.

9. The inductor structure as claimed in claim 1, further comprising:

an etch stop layer formed on the first metal layer, wherein the magnetic layer is insulated from the first metal layer by the etch stop layer.

10. The inductor structure as claimed in claim 1, further comprising:

vias formed in the second dielectric layer; and

a second metal layer formed on the vias, wherein the second metal layer is electrically connected to the first metal layer by the vias.

11. The inductor structure as claimed in claim 1, wherein the magnetic layer has a polygon structure.

16. A method for forming the inductor structure of claim 1, comprising:

providing a substrate;

forming a first metal layer in a first dielectric layer;

forming and patterning a oxide layer to form an opening in the oxide layer;

conformally forming a magnetic material on the oxide layer and in the opening;

forming a photoresist layer over the magnetic material;

performing a wet etching process on the magnetic material to form a magnetic layer;

after performing the wet etching process, the magnetic layer comprising sidewall surfaces which comprise a first pair of sidewall surfaces adjoin the bottom surface and a second pair of sidewall surfaces adjoin the first pair of sidewall surfaces, wherein

the first pair of sidewall surfaces are vertical to the bottom surface of the magnetic layer; and

the second pair of sidewall surfaces taper gradually toward the top surface of the magnetic layer;

forming a second dielectric layer on the magnetic layer; and

forming a second metal layer on the second dielectric layer.

17. The method for forming an inductor structure as claimed in claim 16, wherein performing the wet etching process comprises using a wet etching solution comprising HF, HNO3 and water.

18. The method for forming an inductor structure as claimed in claim 16, before forming and patterning the oxide layer, further comprising:

forming an etching stop layer on the first dielectric layer.

19. The method for forming an inductor structure as claimed in claim 16, wherein a ratio of a height of the oxide layer to a height of the magnetic material is in a range from about 0.2 to about 5.

20. The method for forming an inductor structure as claimed in claim 16, before forming the second metal layer on the second dielectric layer, further comprising:

forming vias in the second dielectric layer and oxide layer.

12. An inductor structure, comprising:

a substrate;

a first metal layer formed in a first dielectric layer;

a magnetic layer formed on the first dielectric layer, wherein the magnetic layer has an octagon or trapezoid structure, and wherein the magnetic layer has sidewall surfaces which comprise a first pair of sidewall surfaces adjoin the bottom surface and a second pair of sidewall surfaces adjoin the first pair of sidewall surfaces wherein

the first pair of sidewall surfaces are vertical to the bottom surface of the magnetic layer; and

the second pair of sidewall surfaces taper gradually toward the top surface of the magnetic layer;

an oxide layer formed adjacent to magnetic layer;

a second dielectric layer formed over the magnetic layer and the oxide layer; and

a second metal layer formed on a second dielectric layer.

13. The inductor structure as claimed in claim 12, further comprising:

an etch stop layer formed on the first metal layer, wherein the first metal layer is insulated from the magnetic layer by an etch stop layer.

14. The inductor structure as claimed in claim 12, wherein the magnetic layer has a top surface, a bottom surface and sidewall surfaces between the top surface and the bottom surface, and the sidewall surfaces have at least two intersection points.

15. The inductor structure as claimed in claim 12, further comprising:

vias formed in the second dielectric layer and the oxide layer, wherein the first metal layer is electrically connected to the second metal layer through the vias.