Copper conductor

• US 20060006070A1
• Filed: 07/09/2004
• Published: 01/12/2006
• Est. Priority Date: 07/09/2004
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Lane, Michael, Edelstein, Daniel C., Spooner, Terry A., Chiras, Stefanie R., Rosenberg, Robert
• Granted Patent: US 7,119,018 B2
• Time in Patent Office: Days
• US Class Current: 205/74
• CPC Class Codes: C25D 5/10 Electroplating with more than one layer of the same or of different metals for bearings C25D7/10
• CPC Class Codes: C25D 5/50 by heat-treatment
• CPC Class Codes: C25D 7/123 Semiconductors first coated with a seed layer or a conductive layer
• CPC Class Codes: H01L 21/2885 using an external electrical current, i.e. electro-deposition
• CPC Class Codes: H01L 21/76807 for dual damascene structures
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76849 the layer being positioned on top of the main fill metal
• CPC Class Codes: H01L 21/76867 characterized by methods of formation other than PVD, CVD or deposition from a liquids PVD H01L21/2855; CVD H01L21/28556; deposition from liquids H01L21/288
• CPC Class Codes: H01L 21/76873 for electroplating
• CPC Class Codes: H01L 21/76874 for electroless plating
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 21/76886 Modifying permanently or temporarily the pattern or the conductivity of conductive members, e.g. formation of alloys, reduction of contact resistances
• CPC Class Codes: H01L 23/53233 Copper alloys
• 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 conducting material comprising: a conducting core region comprising copper and from 0.001 atomic percent to 0.6 atomic percent of one or more metals selected from iridium, osmium and rhenium; and an interfacial region. The interfacial region comprises at least 80 atomic percent or greater of the one or more metals. The invention is also directed to a method of making a conducting material comprising: providing an underlayer; contacting the underlayer with a seed layer, the seed layer comprising copper and one or more metals selected from iridium, osmium and rhenium; depositing a conducting layer comprising copper on the seed layer, and annealing the conducting layer at a temperature sufficient to cause grain growth in the conducting layer, yet minimize the migration of the one or more alloy metals from the seed layer to the conducting layer. The method further comprises polishing the conducting layer to provide a polished copper surface material, and annealing the polished copper surface material at a temperature to cause migration of the one or more metals from the seed layer to the polished surface to provide an interfacial region in contact with a copper conductor core region. The interfacial region and the copper conductor core region comprise the one or more metals.

Claims

1. A conducting material comprising:

a conducting core region comprising copper and from 0.001 atomic percent to 0.6 atomic percent of one or more metals selected from the group consisting of iridium, osmium and rhenium; and

an interfacial region, wherein the interfacial region comprises at least 80 atomic percent of the one or more metals.

2. The conducting material of claim 1, wherein the interfacial region comprises at least 90 atomic percent of iridium.

3. The conducting material of claim 2, wherein the conducting core region comprises from 0.001 atomic percent to 0.4 atomic percent of iridium.

4. The conducting material of claim 2, wherein the conducting core region comprises from 0.001 atomic percent to 0.2 atomic percent of iridium.

5. The conducting material of claim 2, further comprising a seed region, wherein the seed region comprises from 0.5 atomic percent to 4 atomic percent of iridium.

6. The conducting material of claim 1, wherein the interfacial region is from 5 Å

to 20 Å

in thickness.

7. The conducting material of claim 2, wherein the electrical resistivity of the conducting material is 2.3 μ

Ω

/cm or less.

8. The conducting material of claim 1, wherein the conducting core region comprises from 0.001 atomic percent to 0.4 atomic percent of the one or more metals.

9. A semiconductor structure comprising:

a trench or a via disposed within a dielectric material, wherein the trench or via includes an underlayer disposed along the sidewalls of the trench or the via;

a copper conductor core within the trench or the via, wherein the conductor core comprises from 0.01 atomic percent to 0.6 atomic percent of one or more metals selected from the group consisting of iridium, osmium and rhenium; and

an interfacial layer comprising 80 atomic percent or greater of the one or more metals.

10. The semiconductor structure of claim 9, wherein the interfacial region comprises 90 atomic percent of iridium or greater.

11. The semiconductor structure of claim 10, wherein the copper conductor core comprises from 0.001 atomic percent to 0.4 atomic percent of iridium.

12. The semiconductor structure of claim 10, wherein the copper conductor core comprises from 0.001 atomic percent to 0.2 atomic percent of iridium.

13. The semiconductor structure of claim 10, further comprising a seed region disposed on the underlayer, wherein the seed region comprises from 0.5 atomic percent to 4 atomic percent of iridium.

14. The semiconductor structure of claim 9, wherein the interfacial region is about 5 Å

to about 20 Å

in thickness.

15. The semiconductor structure of claim 10, wherein the electrical resistivity of the conducting material is 2.3 μ

Ω

/cm or less.

16. The semiconductor structure of claim 9, wherein the conducting core region comprises from 0.001 atomic percent to 0.4 atomic percent of the one or more metals.

17. A conducting material comprising:

a seed region comprising copper and 0.3 atomic percent to 1.8 atomic percent of iridium;

a conducting core region comprising copper and from 0.04 atomic percent to 0.1 atomic percent of iridium; and

an interfacial region, wherein the interfacial region comprises at least 98 atomic percent iridium.

18. The conducting material of claim 17, wherein the conducting core region comprises from 0.05 atomic percent to 0.08 atomic percent of iridium.

19. The conducting material of claim 17, wherein the interfacial region is from 5 Å

to 20 Å

in thickness.

20. The conducting material of claim 17, wherein the electrical resistivity of the conducting material is 2.1 μ

Ω

/cm or less.

21. A method of making a conducting material comprising:

providing an underlayer;

contacting the underlayer with a seed layer, wherein the seed layer comprises copper and one or more metals selected from the group consisting of iridium, osmium and rhenium;

depositing a conducting layer comprising copper on the seed layer, and annealing the conducting layer at a temperature sufficient to cause grain growth in the conducting layer, yet minimize the migration of the one or more metals from the seed layer to the conducting layer;

polishing the conducting layer to provide a polished copper surface material; and

annealing the polished copper surface material at a temperature to cause migration of the one or more metals from the seed layer to the polished surface to provide a copper conductor core region in contact with an interfacial region, wherein the interfacial region and the copper conductor core region comprise the one or more metals.

22. The method of claim 21, wherein the one or more metals includes iridium, and the seed layer contains from 1 atomic percent to 7 atomic percent of iridium prior to annealing the conducting layer or annealing the polished copper surface material.

23. The method of claim 21, wherein annealing the conducting layer includes not exceeding a temperature of 200°

C. for more than 5 minutes.

24. The method of claim 21, wherein annealing the polished copper surface material includes a temperature of 250°

C. or greater for 30 minutes or more.

25. The method of claim 21, wherein the migration of the one or more metals to the polished copper surface material provides the interfacial region with 80 atomic percent or greater of the one or more metals.

26. The method of claim 22, wherein the migration of the iridium to the polished copper surface material provides the interfacial region with 90 atomic percent of iridium or greater.

27. The method of claim 21, wherein the copper conductor core comprises 0.001 atomic percent to 0.6 atomic percent of the one or more metals.

28. The method of claim 22, wherein the core copper conductor comprises 0.001 atomic percent to 0.4 atomic percent iridium.

29. The method of claim 22, wherein the copper conductor core comprises 0.001 atomic percent to 0.2 atomic percent iridium.

30. The method of claim 22, wherein the migration of the iridium provides a seed region with 0.5 atomic percent to 4 atomic percent of iridium.

31. The method of claim 21, wherein the migration of the one or more metals provides the interfacial region with a thickness from 5 Å

to about 20 Å

.