Inductor structures for integrated circuits

• US 10,128,325 B2
• Filed: 03/23/2015
• Issued: 11/13/2018
• Est. Priority Date: 03/26/2014
• Status: Active Grant

• Current Assignee: Wafertech LLC (Taiwan Semiconductor Manufacturing Company Limited)
• Original Assignee: Wafertech LLC (Taiwan Semiconductor Manufacturing Company Limited)
• Inventors: Lam, Kin Fung (Wayne), Li, Hsin-I, Tsai, Wen-Bin
• Primary Examiner(s): Enad, Elvin G
• Assistant Examiner(s): Barnes, Malcolm
• Application Number:
  US14/666,107
• Publication Number:
  US 20150279921A1
• Time in Patent Office: 1,331 Days
• Field of Search: 257531
• 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

Multiple intertwined inductor coils combine to form one or more transformer devices of a semiconductor device. The intertwined inductor coils are formed of only two metallization layers and vias coupling the layers. The inductor coils are vertically oriented and include a magnetic axis parallel to the substrate surface. A plurality of metal wires are provided on both a first device level and a second device level. Each of the metal wires on the first device level is coupled to two wires on the second device level and forms a first inductor coil. The two metal wires on the second device level that form part of the first inductor coil, are separated by a third wire that is coupled to two different first device level metal wires and forms part of a different second inductor coil intertwined with the first inductor coil.

Claims

1. A device comprising:

a transformer on a semiconductor device including first, second, and third inductor coils, each said inductor coil comprising;

a plurality of first level metal wires along a first level coupled to a plurality of second level metal wires along a second level through vias, the first level separated from the second level,

said second level metal wires being parallel to one another, and

said plurality of said first level metal wires including;

a first zig-zag segment and a second zig-zag segment laterally spaced from one another with a third zig-zag segment, and

a fourth zig-zag segment and a fifth zig-zag segment laterally spaced from one another with a sixth zig-zag segment,

wherein the first, second, fourth, and fifth zig-zag segments belong to the first inductor coil, the third zig-zag segment belongs to the second inductor coil, and the sixth zig-zag segment belongs to the third inductor coil, and

wherein each of the first, second, third, fourth, fifth, and sixth zig-zag segments comprises first and second parallel sub-segments coupled by a third intermediate sub-segment that is angled from the first and second parallel sub-segments, and at least one of the parallel first and second sub-segments of the first inductor coil includes an elongated sub-segment along the first level extending beyond other parallel sub-segments of the first inductor coil so as to facilitate coupling between the elongated sub-segment and a contact, wherein the elongated sub-segment is continuous along the first level with the at least one of the parallel first and second sub-segments.

2. The device as in claim 1, wherein said first zig-zag segment is overlaid with and coupled to a first wire of said second level metal wires, the second zig-zag segment is parallel to said first segment and overlaid with and coupled to a second wire of said second level metal wires, said first and second wires that belong to the first inductor coil are spaced apart by at least a third wire of said second level metal wires that belongs to the second inductor coil, said fourth zig-zag segment is overlaid with and coupled to a third wire of said second level metal wires, the fifth zig-zag segment is parallel to said fourth zig-zag segment and overlaid with and coupled to a fourth wire of said second level metal wires, said third and fourth wires that belong to the first inductor coil are spaced apart by at least a fifth wire of said second level metal wires that belongs to the third inductor coil and said second level metal wires are straight.

3. The device as in claim 1, wherein said second level metal wires are straight, said first, second, third, fourth, fifth, and sixth zig-zag segments are parallel to one another.

4. The device as in claim 3, wherein each of said first, second, third, fourth, fifth, and sixth zig-zag segments is coupled to one of said second level metal wires by at least two vias.

5. The device as in claim 1, wherein said first level metal wires are formed of a lower metal level of said semiconductor device and said second level metal wires are formed of an upper metal level of said semiconductor device.

6. The device as in claim 1, wherein said first level metal wires are formed of an upper metal level of said semiconductor device and said second level metal wires are formed of a lower metal level of said semiconductor device.

7. The device as in claim 1, wherein each said first level metal wire is coupled to two wires of said second level metal wires, said two wires spaced apart by at least a third wire of said second level metal wires.

8. An inductor structure on a semiconductor device comprising:

a plurality of first level metal wires along a first level;

a plurality of second level metal wires along a second level, each including a duality of parallel segments coupled by a further segment angled from the duality of parallel segments;

each said second level metal wire including a first parallel segment of said duality of parallel segments coupled to a first wire of said first level metal wires overlaid with said first segment, and a second parallel segment of said duality of parallel segments coupled to a second wire of said first level metal wires overlaid with said second segment, said first and second wires spaced apart by at least a third wire of said second level metal wires;

wherein said plurality of first level metal wires are coupled to said plurality of second metal wires to form first and second coils in which adjacent ones of said first level metal wires form parts of different coils of said first and second coils,

wherein at least one of the parallel segments of the first coil includes an elongated segment extending beyond other parallel segments of the first coil along the second level so as to facilitate coupling between the elongated segment and a contact, and

wherein the elongated segment is continuous along the first level with the least one of the parallel segments of the first coil.

9. The inductor structure as in claim 8, wherein adjacent ones of said second level metal wires form parts of different coils of said duality of coils.

10. The inductor structure as in claim 8, wherein said first level metal wires of said plurality of first level metal wires are straight and parallel one another.

11. The inductor structure as in claim 8, wherein said further segment is an angled straight segment that forms an angle of about 135°

with each of said duality of parallel segments.

12. The inductor structure as in claim 8, wherein, for each said second level metal wire, said first segment is coupled to said first wire by a duality of vias and said second segment is coupled to said second wire by a duality of vias.

13. The inductor structure as in claim 12, wherein said first level metal wires are straight, parallel to one another, and formed of an upper metal level of said semiconductor device, said second level metal wires are formed of a lower metal level of said semiconductor device, said vias include a height of about 8 k angstroms to about 12 k angstroms and said first level metal wires and said second level metal wires each have an average width of about 1-2 microns.

14. The inductor structure as in claim 8, wherein said first level metal wires are straight, parallel to one another, and formed of a lower metal level of said semiconductor device and said second level metal wires are formed of an upper metal level of said semiconductor device.

15. A transformer device on a semiconductor device comprising:

first, second, and third inductor coils formed of a plurality of first level metal wires along a first level coupled to a plurality of second level metal wires along a second level,

wherein said first inductor coil comprises first and second subsets of segments of said second level metal wires,

wherein said second inductor coil comprises at least one first segment of said second level metal wires, at least two of said first subset of segments of said first inductor coil are parallel and separated by said at least one first segment of said second inductor coil,

wherein said third inductor coil comprises at least one second segment of said second level metal wires, at least two of said second subset of segments of said first inductor coil are parallel and separated by said at least one second segment of said third inductor coil,

wherein each of the first and second subsets of segments of said first inductor coil comprises first and second parallel sub-segments coupled by a third intermediate sub-segment that is angled from the first and second parallel sub-segments along the second level, and at least one of the first and second parallel sub-segments of the first inductor coil includes an elongated sub-segment along the second level extending beyond other parallel sub-segments of the first inductor coil so as to facilitate coupling between the elongated sub-segment and a contact,

wherein the elongated sub-segment is continuous along the first level with the at least one of the first and second parallel sub-segments, and

wherein each of said first level metal wires are substantially straight.

16. The transformer device as in claim 15, wherein said plurality of first metal wires are parallel one another, said plurality of second metal wires are parallel one another and include a zig-zag structure, and each of said plurality of first metal wires is coupled to two of said plurality of second metal wires.

17. The transformer device as in claim 15, wherein said first metal wires are adjacent one another and immediately adjacent ones of said first level metal wires are coupled to different inductor coils of said plurality of inductor coils in a first group of said first level metal wires.

18. The transformer device as in claim 15, wherein said first metal wires are adjacent one another and arranged in a numerical sequence whereby odd-numbered ones of said first level metal wires form a first inductor coil and even-numbered ones of said first level metal wires form a second inductor coil.

19. The transformer device as in claim 18, wherein each of said second level metal wires includes a duality of parallel segments coupled by an angled segment therebetween.