Copper conductor

• US 7,119,018 B2
• Filed: 07/09/2004
• Issued: 10/10/2006
• Est. Priority Date: 07/09/2004
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Edelstein, Daniel C., Lane, Michael W., Spooner, Terry A., Chiras, Stefanie R., Rosenberg, Robert
• Primary Examiner(s): POTTER, ROY KARL
• Application Number:
  US10/887,087
• Publication Number:
  US 20060006070A1
• Time in Patent Office: 823 Days
• Field of Search: 257/762, 438/687, 438/686, 438/E23.005, 438/23.011
• US Class Current: 438/686
• 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 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.

2. The method of claim 1, 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.

3. The method of claim 1, wherein annealing the conducting layer includes not exceeding a temperature of 200°

C. for more than 5 minutes.

4. The method of claim 1, wherein annealing the polished copper surface material includes a temperature of 250°

C. or greater for 30 minutes or more.

5. The method of claim 1, 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.

6. The method of claim 2, wherein the migration of the iridium to the polished copper surface material provides the interfacial region with 90 atomic percent of iridium or greater.

7. The method of claim 1, wherein the copper conductor core comprises 0.001 atomic percent to 0.6 atomic percent of the one or more metals.

8. The method of claim 2, wherein the core copper conductor comprises 0.001 atomic percent to 0.4 atomic percent iridium.

9. The method of claim 2, wherein the copper conductor core comprises 0.001 atomic percent to 0.2 atomic percent iridium.

10. The method of claim 2, wherein the migration of the iridium provides a seed region with 0.5 atomic percent to 4 atomic percent of iridium.

11. The method of claim 1, wherein the migration of the one or more metals provides the interfacial region with a thickness from 5 Å

to about 20 Å

.