Inductor for post passivation interconnect and a method of forming

• US 9,553,045 B2
• Filed: 04/06/2015
• Issued: 01/24/2017
• Est. Priority Date: 03/13/2012
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Tsai, Hao-Yi, Chen, Hsien-Wei, Kuo, Hung-Yi, Chen, Jie, Chen, Ying-Ju, Yu, Tsung-Yuan
• Primary Examiner(s): NIKMANESH, SEAHVOSH J
• Application Number:
  US14/679,717
• Publication Number:
  US 20150214148A1
• Time in Patent Office: 659 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/768 Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
• CPC Class Codes: H01L 2224/02351 comprising interlocking features
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/06515 Bonding areas having different functions
• CPC Class Codes: H01L 23/5225 Shielding layers formed together with wiring layers
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 23/552 Protection against radiation, e.g. light or electromagnetic waves
• CPC Class Codes: H01L 23/585 comprising conductive layers or plates or strips or rods or rings H01L23/60, H01L23/62, H01L23/64, H01L23/66 take precedence
• CPC Class Codes: H01L 24/03 Manufacturing methods
• CPC Class Codes: H01L 24/11 Manufacturing methods for bumps on insulating substrates H01L21/4853
• CPC Class Codes: H01L 28/10 Inductors
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor

Abstract

An inductor device and method of forming the inductor device are provided. In some embodiments the inductor device includes a post passivation interconnect (PPI) layer disposed and an under bump metallization (UBM) layer, each disposed over a substrate. The PPI layer forms a coil and dummy pads. The dummy pads are disposed around a substantial portion of the coil to shield the coil from electromagnetic interference. A first portion of the UBM layer is electrically coupled to the coil and configured to interface with an electrical coupling member.

Claims

1. A method of forming an inductor device, the method comprising:

forming a coil over a substrate;

forming dummy pads over the substrate in a post passivation interconnect (PPI) layer, the dummy pads configured to shield the coil from electromagnetic interference; and

depositing first portions of an under bump metallization (UBM) layer over respective ones of the dummy pads.

2. The method of claim 1, forming the coil and forming the dummy pads comprises simultaneously forming the coil and the dummy pads in a same PPI layer.

3. The method of claim 1, forming the coil and depositing the first portions of the UBM layer comprises forming the coil using a second portion of the UBM layer simultaneously with the depositing the first portions of the UBM layer.

4. The method of claim 3, further comprising depositing a surface finish over the dummy pads and the coil.

5. The method of claim 1, further comprising forming a finish layer over the first portions of the UBM layer.

6. The method of claim 1, electrically coupling the first portions of the UBM layer and the dummy pads to a low voltage.

7. The method of claim 1, wherein the dummy pads have a width greater than a width of the first portion of the UBM.

8. A method of forming an inductor device, the method comprising:

forming a coil over a substrate;

forming a post passivation interconnect (PPI) layer, the forming the PPI comprising patterning a conductive layer to form a plurality of dummy pads, the plurality of dummy pads being arranged around a perimeter of the coil in a plan view; and

forming an under bump metallization (UBM) over respective ones of the plurality of dummy pads.

9. The method of claim 8, wherein the UBM has a first width and the dummy pads have a second width, the first width greater than the second width.

10. The method of claim 8, wherein the UBM has a first width and the dummy pads have a second width, the first width less than the second width.

11. The method of claim 8, wherein the coil is in the PPI.

12. The method of claim 8, wherein the coil is in a same level as the UBM.

13. The method of claim 12, further comprising a finish layer over the coil.

14. The method of claim 8, wherein the dummy pads are coupled to ground.

15. A method of forming an inductor device, the method comprising:

forming a top metallization layer over a substrate;

forming a first passivation layer over the top metallization layer;

forming a coil over the first passivation layer; and

forming dummy pads over the first passivation layer, the dummy pads being arranged around a perimeter of the coil in a plan view.

16. The method of claim 15, further comprising forming first under bump metallizations (UBMs) over respective ones of the dummy pads and forming a second UBM coupled to the coil.

17. The method of claim 16, wherein the coil is formed directly over a same dielectric layer as the second UBM.

18. The method of claim 16, wherein the second UBM and the coil are separated by a dielectric layer.

19. The method of claim 15, wherein a width of the dummy pads is greater than a width of the first UBMs.

20. The method of claim 15, further comprising forming a first contact pad and a second contact pad to the coil, wherein the first contact pad and the second contact pad are arranged in line with the dummy pads in a plan view.