Vertical slow-wave symmetric inductor structure for semiconductor devices

• US 9,508,480 B2
• Filed: 08/31/2011
• Issued: 11/29/2016
• Est. Priority Date: 08/31/2011
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Cho, Hsiu-Ying
• Primary Examiner(s): Enad, Elvin G
• Assistant Examiner(s): Hinson, Ronald
• Application Number:
  US13/222,665
• Publication Number:
  US 20130049919A1
• Time in Patent Office: 1,917 Days
• Field of Search: 336/200, 336/223, 336/232
• US Class Current: 1/1
• CPC Class Codes: H01F 17/0013 with stacked layers
• CPC Class Codes: H01F 2017/0073 with a special conductive pattern, e.g. flat spiral
• CPC Class Codes: H01F 2017/008 Electric or magnetic shielding of printed inductances
• CPC Class Codes: H01F 2017/0086 on semiconductor substrate
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645

Abstract

A vertical inductor structure in a semiconductor device includes a plurality of vertically oriented spirals that produce magnetic field in a dielectric material above the surface of a semiconductor substrate thereby preventing any eddy currents from propagating in the substrate. An inductor shield structure is also provided. The inductor shield structure is formed over the substrate surface and between an inductor such as the vertical inductor structure or other inductor types and also prevents eddy currents from being induced in the substrate. The inductor shield may surround the inductor to various degrees.

Claims

1. A semiconductor device comprising an inductor structure formed on a semiconductor substrate with a planar substrate surface, said inductor structure comprising at least two flat spiral conductive structures, each of said flat spiral conductive structures formed of at least three horizontal strips of conductive material vertically separated, each of said horizontal strips having a respective horizontal area, wherein a projected horizontal area of each of said flat spiral conductive structure is equal to said horizontal area of a longest one of said strips, wherein each of said horizontal strips of conductive material comprise outer edges that are vertically aligned with each other in a direction substantially normal to said planar substrate surface, and wherein said horizontal strips of conductive material of a first of said at least two flat spiral conductive structures and said horizontal strips of conductive material of a second of said at least two flat spiral conductive structures are aligned such that a primary axis of a magnetic field of the first flat spiral conductive structure is in line with a primary axis of a magnetic field of the second flat spiral conductive structure, further comprising a shield comprising a plurality of adjacent strips extending between at least two of the horizontal strips of the first and second flat spiral structures, and wherein said plurality of adjacent strips are perpendicular to said flat spiral structures.

2. The semiconductor device as in claim 1, wherein said at least three horizontal strips of conductive materials are formed in dielectric materials disposed over said planar substrate surface and said flat spiral conductive structures are electrically coupled and include a common center port coupled to ground.

3. The semiconductor device as in claim 1, wherein said vertically separated horizontal strips of conductive material comprise at least three metal layers, and vertical connective conductive structures and further comprising a shield at least partially surrounding said inductor structure, said shield comprising a plurality of adjacent strips formed of a semiconductor material and separated by a dielectric material.

4. The semiconductor device as in claim 1, wherein each of said flat spiral conductive structures includes at least one vertical conductive member disposed at different vertical locations, each said at least one vertical conductive member having the same horizontal area and coplanar lateral edges as said horizontal strips of conductive material.

5. The semiconductor device as in claim 1, wherein said inductor structure is formed in a dielectric disposed on said planar substrate surface and magnetic fields produced by said inductor structure are substantially above said planar substrate surface.

6. The semiconductor device as in claim 1, wherein magnetic fields produced by said inductor structure are oval in shape with primary axes substantially parallel to said planar substrate surface.

7. The semiconductor device as in claim 1, wherein said inductor structure is formed in a dielectric disposed on said planar substrate surface, wherein said shield at least partially surrounding said inductor structure, said plurality of adjacent strips separated by said dielectric material, said strips formed of one of a conductor and a semiconductor material.

8. The semiconductor device as in claim 7, wherein said shield includes said plurality of strips including strips disposed above and below said inductor structure, each of said plurality of strips having the same length and wherein each of said plurality of strips has each of their opposed ends joined together by a corresponding unitary endplate structure.

9. The semiconductor device as in claim 7, wherein said shield is formed of one of polysilicon, metal, or polysilicon and metal.

10. The semiconductor device as in claim 7, wherein said flat spiral conductive structures are substantially parallel to one another, disposed in and spaced apart by said dielectric material and electrically coupled together at a common central port and wherein said strips are disposed in said dielectric material and substantially orthogonal to said at least three horizontal conductive strips of said flat spiral conductive structures, and extend between and laterally past said at least three horizontal strips of conductive material of each of said at least two flat spiral conductive structures.

11. The semiconductor device as in claim 1, wherein said inductor structure comprises four said flat spiral conductive structures substantially parallel to one another and formed in dielectric materials disposed over said planar substrate surface, said flat spiral conductive structures coupled to one another and including a common center port coupled to ground.

12. The semiconductor device as in claim 1, wherein said semiconductor device is an RF device.

13. An RF semiconductor integrated circuit comprising:

a semiconductor substrate with a planar substrate surface;

an inductor device disposed over said semiconductor substrate, wherein said inductor device comprises at least two spiral coils each formed of at least three horizontal strips of conductive material vertically separated, each of said horizontal strips having a horizontal area, wherein a projected horizontal area of said flat spiral conductive structure is equal to said horizontal area of a longest one of said strips, wherein each of said horizontal strips of conductive material comprise outer edges that are vertically aligned with each other in a direction orthogonal to said planar substrate surface, and wherein said horizontal strips of conductive material of a first of said at least two spiral coils and said horizontal strips of conductive material of a second of said at least two spiral coils are aligned such that a primary axis a magnetic field of the first flat spiral conductive structure is in line with a primary axis of a magnetic field of the second flat spiral conductive structure; and

a shield comprising a plurality of adjacent strips extending between at least two of the horizontal strips of the first and second flat spiral structures.

14. The RF semiconductor integrated circuit as in claim 13, wherein said inductor device is disposed in a dielectric material disposed over said planar substrate surface and said at least three horizontal strips of conductive material are formed of metal leads disposed over one another and formed from a plurality of metal layers, and wherein said at least three horizontal strips of conductive material are coupled by vertical conductive connectors.

15. A semiconductor device comprising an inductor structure formed in a dielectric material and over a semiconductor substrate with a substrate surface, and an inductor shield formed in said dielectric material between said inductor structure and said substrate surface,

said inductor shield including a plurality of strips of conductive material or semiconductor material separated by a dielectric, a first end plate, and a second end plate, wherein said plurality of strips extend from the first end plate to the second end plate, and

said inductor structure including at least two substantially flat spiral coils each formed of at least three horizontal strips of conductive or semiconductor material vertically separated by a dielectric, each of said at least three horizontal strips of conductive material having a horizontal area, and aligned directly over one another such that said inductor structure has a projected horizontal area equal to an area of a longest of one of said three horizontal strips of conductive material, and wherein said horizontal strips of conductive material of a first of said at least two substantially flat spiral coils and said horizontal strips of conductive material of a second of said at least two substantially flat spiral coils are aligned such that a primary axis a magnetic field of the first flat spiral conductive structure is in line with a primary axis of a magnetic field of the second flat spiral conductive structure, wherein said plurality of strips extending between at least two of the horizontal strips of the first and second flat spiral structures, wherein said plurality of adjacent strips are perpendicular to said flat spiral structures.

16. The semiconductor device as in claim 15, wherein said plurality of vertically separated strips of conductive material or semiconductor material are coplanar and substantially parllel to said substrate surface and wherein each of said at least two substantially flat spiral coils are oriented orthogonal to said substrate surface.

17. The semiconductor device as in claim 15, wherein said inductor shield further comprises a plurality of further strips of conductive material or semiconductor material disposed in said dielectric material and over said inductor structure and at least two opposed endplates of said conductive material or semiconductor material, each of said strips and said further strips having each of their opposed ends terminating at a corresponding one of said at least two opposed endplates.

18. The semiconductor device as in claim 17, wherein said inductor structure comprises at least two flat spiral coils, each oriented normal to said substrate surface and further comprising a plurality of intermediate strips of said conductive material or semiconductor material formed in said dielectric material and extending between said opposed endplates and through said at least two flat spiral coils.