Density transition zones for integrated circuits

• US 8,159,044 B1
• Filed: 11/20/2009
• Issued: 04/17/2012
• Est. Priority Date: 11/20/2009
• Status: Active Grant

• Current Assignee: Altera Corporation (Intel Corporation)
• Original Assignee: Altera Corporation (Intel Corporation)
• Inventors: Chen, Shuxian, Richter, Fangyun, Jensen, Bradley, Liu, Yowjuang (Bill)
• Primary Examiner(s): Dang, Phuc
• Application Number:
  US12/623,161
• Time in Patent Office: 879 Days
• Field of Search: 257/516, 257/528, 257/531, 257/E27.001
• US Class Current: 257/531
• CPC Class Codes: H01L 23/522 including external interconnections consisting of a multilayer structure of conductive and insulating layers inseparably formed on the semiconductor body
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 27/0207 Geometrical layout of the components, e.g. computer aided design; custom LSI, semi-custom LSI, standard cell technique
• 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

An integrated circuit is provided with a spiral inductor and a transition zone surrounding the spiral inductor. The transition zone may have a geometry that is substantially eight-sided or octagonal. Metal layers in the transition zone may have metal fill that is substantially octagonal and arranged in rows and columns. If desired, square or rectangular metal fill be tiled with the substantially octagonal metal fill. Metal layers may also contain halved or quartered octagonal metal fill. Substrate in the transition zone may have octagonal substrate regions separated by shallow trench isolation regions. A polysilicon layer above the substrate may have square regions of polysilicon fill directly above the shallow trench regions in the substrate. Such arrangements may provide more uniform densities in transition zones with certain geometries.

Claims

1. An integrated circuit, comprising:

a spiral inductor formed in metal layers of a dielectric stack;

octagonal dummy fill structures surrounding the spiral inductor, wherein the octagonal dummy fill structures comprise octagonal metal fill structures formed in the metal layers of the dielectric stack; and

square metal fill structures formed in the metal layers of the dielectric stack that form an alternating transition zone pattern with the octagonal metal fill structures.

2. The integrated circuit defined in claim 1, wherein at least one of the octagonal dummy fill structures comprises four separate fill structures that together form the octagonal dummy fill structure.

3. An integrated circuit, comprising:

a spiral inductor formed in metal layers of a dielectric stack; and

octagonal dummy fill structures surrounding the spiral inductor, wherein the octagonal dummy fill structures comprise octagonal metal fill structures formed in the metal layers of the dielectric stack and wherein the octagonal metal fill structures in each of the metal layers of the dielectric stack are aligned with the octagonal metal fill structures in other metal layers among the metal layers of the dielectric stack.

4. An integrated circuit, comprising:

a spiral inductor formed in metal layers of a dielectric stack; and

octagonal dummy fill structures surrounding the spiral inductor, wherein the octagonal dummy fill structures comprise octagonal metal fill structures formed in the metal layers of the dielectric stack and wherein the octagonal metal fill structures in at least a first of the metal layers of the dielectric stack are offset from the octagonal metal fill structures in a second of the metal layers of the dielectric stack.

5. An integrated circuit, comprising:

a spiral inductor formed in metal layers of a dielectric stack; and

octagonal dummy fill structures surrounding the spiral inductor, wherein the octagonal dummy fill structures comprise octagonal substrate regions in a substrate, the integrated circuit further comprising;

shallow trench isolation regions in the substrate between the octagonal substrate regions.

6. The integrated circuit defined in claim 5, further comprising:

rectangular polysilicon fill structures in a polysilicon layer above the substrate, wherein the rectangular polysilicon fill structures are directly above the shallow trench isolation regions in the substrate.

7. An integrated circuit, comprising:

a spiral inductor formed in metal layers of a dielectric stack; and

octagonal dummy fill structures surrounding the spiral inductor, wherein the octagonal dummy fill structures are located in a transition zone surrounding the spiral inductor and wherein the transition zone has inner and outer boundaries that are substantially octagonal.

8. The integrated circuit defined in claim 7, further comprising:

halved octagonal fill structures at one of the inner and outer boundaries.

9. The integrated circuit defined in claim 7, further comprising:

triangular fill structures at one of the inner and outer boundaries.

10. The integrated circuit defined in claim 7, further comprising rectangular fill structures at one of the inner and outer boundaries.

11. An integrated circuit, comprising:

a spiral inductor formed in metal layers of a dielectric stack; and

octagonal dummy fill structures surrounding the spiral inductor, wherein the octagonal dummy fill structures are arranged in rows and columns.

12. An integrated circuit, comprising:

a spiral inductor; and

dummy fill structures surrounding the spiral inductor, wherein each dummy fill structure has non-perpendicular edges and wherein the dummy fill structures comprise octagonal substrate regions in a substrate that are separated by shallow trench isolation regions.

13. The integrated circuit defined in claim 12, wherein at least some of the dummy fill structures each comprise at least eight of the non-perpendicular edges.

14. The integrated circuit defined in claim 12, wherein the dummy fill structures comprise octagonal dummy metal fill structures.

15. The integrated circuit defined in claim 12, further comprising:

rectangular polysilicon fill structures in a polysilicon layer over the substrate, wherein the rectangular polysilicon fill structures are located directly above the shallow trench isolation regions.

16. An integrated circuit, comprising:

an inductor; and

octagonal dummy fill structures surrounding the spiral inductor, wherein each of the octagonal dummy fill structures comprises a group of four non-octagonal dummy fill structures.

17. The integrated circuit defined in claim 16 wherein the groups of four non-octagonal dummy fill structures each comprise a group of four non-octagonal dummy metal fill structures formed in metal layers in a dielectric stack.

18. The integrated circuit defined in claim 16, further comprising:

square dummy metal fill structures in metal layers in a dielectric stack that alternate with the groups of four non-octagonal dummy metal fill structures.

19. The integrated circuit defined in claim 16 wherein the groups of four non-octagonal dummy fill structures each comprise a group of four substrate regions in a substrate that are separated by shallow trench isolation regions.

20. The integrated circuit defined in claim 19, further comprising:

rectangular polysilicon fill structures in a polysilicon layer over the substrate, wherein the octagonal dummy fill structures are located in a density transition zone that surrounds the inductor.