Structure for a transformer with magnetic features

• US 8,981,526 B2
• Filed: 12/16/2013
• Issued: 03/17/2015
• Est. Priority Date: 10/25/2011
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Yen, Hsiao-Tsung, Lin, Yu-Ling, Lu, Ying-Ta, Chen, Huan-Neng, Chen, Ho-Hsiang
• Primary Examiner(s): YUSHIN, NIKOLAY K
• Application Number:
  US14/107,794
• Publication Number:
  US 20140097930A1
• Time in Patent Office: 456 Days
• Field of Search: 257/531, 257/E27.01, 336/232, 336/223
• US Class Current: 257/531
• CPC Class Codes: H01F 2027/2809 on stacked layers
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01F 5/003 Printed circuit coils
• CPC Class Codes: H01L 23/5226 Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 23/528 Geometry or layout of the interconnection structure H01L27/0207 takes precedence; algorithms G06F30/00
• 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

The present disclosure provides a semiconductor device. The semiconductor device includes a first inductor formed on a first substrate; a second inductor formed on a second substrate and conductively coupled with the first inductor as a transformer; and a plurality of micro-bump features configured between the first and second substrates. The plurality of micro-bump features include a magnetic material having a relative permeability substantially greater than one and are configured to enhance coupling between the first and second inductors.

Claims

1. A semiconductor device, comprising:

a first inductor formed on a first layer;

a second inductor formed on a second layer and conductively coupled with the first inductor as a transformer;

a plurality of vias configured between the first and second inductors, wherein the plurality of vias includes a first via and a second via; and

at least a subset of the vias includes a magnetic feature configured to enhance inductive coupling between the first and second inductors, and

wherein the first and second vias are electrically disconnected from the first and second inductors.

2. The semiconductor device of claim 1, wherein the first layer includes a semiconductor substrate having an integrated circuit formed thereon, and

wherein the second layer includes an interposer bonded to the first layer.

3. The semiconductor device of claim 2, wherein the interposer includes a silicon substrate having the plurality of vias.

4. The semiconductor device of claim 1, wherein the magnetic feature is electrically disconnected from the first inductor and the second inductor.

5. The semiconductor device of claim 1, further comprising a dielectric under-fill material disposed between the first and second layers such that the magnetic feature is embedded in the under-fill material.

6. The semiconductor device of claim 1, wherein the magnetic feature includes one of nickel, cobalt and iron.

7. The semiconductor device of claim 1, wherein the magnetic feature comprises a material selected from the group consisting of nickel, nickel nitride, and nickel silicide.

8. The semiconductor device of claim 1, wherein the magnetic feature is shaped to have a diameter and a height greater than the diameter.

9. The semiconductor device of claim 1, wherein the magnetic feature includes a plurality of sub-features separated and distributed between the first and second inductors.

10. The semiconductor device of claim 9, wherein each of the sub-features of the magnetic feature has a dimension D in a top view toward top surface,

wherein each of the first and second inductors includes a metal line with a width W, and

wherein a ratio D/W ranges between about 5 and about 20.

11. The semiconductor device of claim 1, wherein the magnetic feature includes a magnetic material having a relative permeability substantially greater than one.

12. The semiconductor device of claim 1, wherein the first inductor is disposed in a first metal layer,

wherein the second inductor is disposed in a second metal layer;

and

wherein the magnetic feature is disposed in a via layer.

13. The semiconductor device of claim 1, wherein the first layer includes a first plurality of metal layers,

wherein the second layer includes a second plurality of metal layers,

wherein the first inductor includes a first spiral structure disposed in the first plurality of metal layers, and

wherein the second inductor includes a second spiral structure disposed in the second plurality of metal layers over the first plurality of metal layers.

14. The semiconductor device of claim 13, wherein the magnetic feature is formed in the first and second plurality of metal layers and is extended through the first and second spiral structures.

15. The semiconductor device of claim 1, wherein each of the first and second inductors includes multiple turns.

16. The semiconductor device of claim 1, wherein the magnetic feature includes a conductive micro-bump.

17. An integrated circuit structure, comprising:

a first layer having a first inductor;

a second layer having a second inductor configured to couple with the first inductor as a transformer;

a first via feature configured approximate the first and second inductors and including a magnetic material with a relative permeability substantially greater than one; and

a second via feature extending between the first inductor and the second inductor, wherein the first and second via features are electrically disconnected from the first and second inductors.

18. The integrated circuit structure of claim 17, wherein the first layer includes a first semiconductor substrate and the second layer includes a second semiconductor substrate.

19. A semiconductor device, comprising:

a first inductor formed on a substrate;

a second inductor formed spaced apart from and conductively coupled with the first inductor; and

a first magnetic feature and a second magnetic feature extending between the first and second inductors to enhance inductive coupling between the first and second inductors, wherein the first and second magnetic features are electrically disconnected from the first and second inductors.

20. The semiconductor device of claim 19, further comprising a through substrate via interposer bonded with the substrate, wherein the first magnetic feature and the second magnetic feature extend through the through substrate via interposer.