Damascene wiring structure and semiconductor device with damascene wirings

• US 6,373,136 B2
• Filed: 12/14/2000
• Issued: 04/16/2002
• Est. Priority Date: 04/14/2000
• Status: Expired due to Term

• Current Assignee: Fujitsu Semiconductor Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Limited
• Inventors: Otsuka, Satoshi, Yamanoue, Akira
• Primary Examiner(s): QUACH, TUAN N
• Application Number:
  US09/735,478
• Publication Number:
  US 20010030365A1
• Time in Patent Office: 488 Days
• Field of Search: 257/758, 257/760, 257/773, 438/622, 438/624, 438/629, 438/637
• US Class Current: 257/758
• CPC Class Codes: H01L 21/76807 for dual damascene structures
• CPC Class Codes: H01L 21/76816 Aspects relating to the layout of the pattern or to the size of vias or trenches layout of the interconnections per se H01L23/528; CAD of ICs G06F30/00
• CPC Class Codes: H01L 23/5226 Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/5283 Cross-sectional geometry
• CPC Class Codes: H01L 23/53228 the principal metal being copper
• 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

A damascene wiring structure having: a lower wiring structure; an interlayer insulating film covering the lower wiring structure; a wiring trench formed in the interlayer insulating film from an upper surface thereof, and a via hole passing through the interlayer insulating film from a lower surface of the wiring trench in an inner area thereof and reaching the lower wiring structure, the via hole having a diameter smaller than a width of the wiring trench; an insulating pillar pattern projecting upward from the lower surface of the wiring trench in an area outside of the via hole, the insulating pillar pattern being made of a same material as the interlayer insulating film, wherein a first occupied area factor of the insulating pillar pattern in a first area of the wiring trench near said via hole is higher than a second occupied area factor of the insulating pillar pattern in a second area of the wiring trench remote from the via hole; and a dual damascene wiring formed by filling the wiring trench and said via hole with conductive material. A damascene wiring structure having a high reliability and a semiconductor device having such a damascene wiring structure can be formed.

Claims

1. A semiconductor device, comprising:

a semiconductor substrate;

an integrated circuit structure formed on said semiconductor substrate;

a multi-layer wiring structure formed above said integrated circuit structure; and

a number of pads formed on said semiconductor substrate, wherein said multi-layer wiring structure comprises;

a lower wiring structure;

an interlayer insulating film covering said lower wiring structure;

a wiring trench formed in said interlayer insulating film from an upper surface thereof, and a via hole passing through said interlayer insulating film from a lower surface of said wiring trench in an inner area thereof and reaching said lower wiring structure, said via hole having a diameter smaller than a width of said wiring trench;

an insulating pillar pattern projecting upward from the lower surface of said wiring trench in an area outside of said via hole, the insulating pillar pattern being made of a same material as said interlayer insulating film, wherein a first occupied area factor of said insulating pillar pattern in a first area of said wiring trench near said via hole is higher than a second occupied area factor of said insulating pillar pattern in a second area of said wiring trench remote from said via hole; and

a dual damascene wiring formed by filling said wiring trench and said via hole with conductive material.

2. A semiconductor device according to claim 1, wherein said plurality of pads include a power supply pad, and said dual damascene wiring is connected to the power supply pad.

3. A damascene wiring structure, comprising:

a lower wiring structure;

an interlayer insulating film covering said lower wiring structure;

a wiring trench formed in said interlayer insulating film from an upper surface thereof, and a via hole passing through said interlayer insulating film from a lower surface of said wiring trench in an inner area thereof and reaching said lower wiring structure, said via hole having a diameter smaller than a width of said wiring trench;

an insulating pillar pattern projecting upward from the lower surface of said wiring trench in an area outside of said via hole, the insulating pillar pattern being made of a same material as said interlayer insulating film, wherein a first occupied area factor of said insulating pillar pattern in a first area of said wiring trench near said via hole is higher than a second occupied area factor of said insulating pillar pattern in a second area of said wiring trench remote from said via hole; and

a dual damascene wiring formed by embedding said wiring trench and said via hole with conductive material.

4. A damascene wiring structure according to claim 3, wherein said wiring trench has a width wider than about 2 μ

m.

5. A damascene wiring structure according to claim 4, wherein the diameter of said via hole is about 1 μ

m or smaller.

6. A damascene wiring structure according to claim 3, wherein said insulating pillar pattern is a plurality of insulating pillars disposed distributively near said via hole.

7. A damascene wiring structure according to claim 6, wherein the first occupied area factor is about 10% or higher.

8. A damascene wiring structure according to claim 7, wherein the first area of said wiring trench near said via hole contains said via hole and is a rectangle area having a side length of 2 μ

m.

9. A damascene wiring structure according to claim 7, wherein the first area of said wiring trench near said via hole contains said via hole and is a rectangle area having a side length of 5 μ

m.

10. A damascene wiring structure according to claim 6, wherein the plurality of insulating pillars are a plurality of first insulating pillars disposed generally at an equal pitch along at least one loop surrounding said via hole, defining a narrow area of said dual damascene wiring between each pair of adjacent first insulating pillars.

11. A damascene wiring structure according to claim 10, wherein said at least one loop includes four or less loops.

12. A damascene wiring structure according to claim 10, wherein the plurality of insulating pillars includes a plurality of second insulating pillars disposed outside of the plurality of first insulating pillars relative to lengthwise direction of said wiring.

13. A damascene wiring structure according to claim 3, wherein said insulating pillar pattern includes a portion surrounding said via hole excepting a partial area.

14. A damascene wiring structure according to claim 13, wherein said insulating pillar pattern includes a U-character shaped insulating pillar pattern surrounding said via hole, and said dual damascene wiring includes a narrow wiring extending along an opening area of the U-character and a wide wiring connected to the narrow wiring at a position remote from said via hole, the wide wiring having a width wider than the narrow wiring.

15. A damascene wiring structure according to claim 14, wherein the narrow wiring has a width five times the diameter of said via hole or narrower, or about 1 μ

m or narrower.

16. A damascene wiring structure according to claim 14, wherein the narrow wiring has a length of 2 μ

m or longer from an end of said via hole to the wide wiring.

17. A damascene wiring structure according to claim 13, wherein said insulating pillar pattern includes two insulating pillar stripes disposed to sandwich said via hole.

18. A damascene wiring structure according to claim 17, wherein said dual damascene wiring includes a narrow wiring connected to said via hole and sandwiched between the two insulating pillar stripes and wide wiring connected to the narrow wiring at areas near opposite ends of the two insulating pillar stripes and remote from said via hole, the wide wiring having a width wider than the narrow wiring.

19. A damascene wiring structure according to claim 18, wherein the narrow wiring has a width five times the diameter of said via hole or narrower, or about 1 μ

m or narrower.

20. A damascene wiring structure according to claim 18, wherein the narrow wiring has a length of 2 μ

m or longer from an end of said via hole to the wide wiring.