Interconnect layers without electromigration

• US 7,585,758 B2
• Filed: 11/06/2006
• Issued: 09/08/2009
• Est. Priority Date: 11/06/2006
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Stamper, Anthony Kendall, Luce, Stephen Ellinwood, McDevitt, Thomas Leddy
• Primary Examiner(s): LEBENTRITT, MICHAEL
• Application Number:
  US11/556,802
• Publication Number:
  US 20080105977A1
• Time in Patent Office: 1,037 Days
• Field of Search: 438/637, 438/597, 438/618, 438/620, 438/622, 438/628, 438/631, 438/633, 438/638, 438/639, 438/643, 438/675, 438/687, 257/E21.004, 257/169, 257/576, 257/577, 257/579, 257/589, 257/591, 257/E23.167, 257/E27.047
• US Class Current: 438/597
• CPC Class Codes: H01L 21/76801 characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing
• CPC Class Codes: H01L 23/5226 Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/53223 Additional layers associated with aluminium layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/53228 the principal metal being copper
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/53252 Additional layers associated with noble-metal layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/53266 Additional layers associated with refractory-metal layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/5329 Insulating materials
• CPC Class Codes: H01L 23/53295 Stacked insulating layers
• 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 structure and a method for forming the same. The structure includes (a) an interlevel dielectric (ILD) layer; (b) a first electrically conductive line and a second electrically conductive line both residing in the ILD layer; (c) a diffusion barrier region residing in the ILD layer. The diffusion barrier region (i) physically isolates, (ii) electrically couples together, and (iii) are in direct physical contact with the first and second electrically conductive lines. The first and second electrically conductive lines each comprises a first electrically conductive material. The diffusion barrier region comprises a second electrically conductive material different from the first electrically conductive material. The diffusion barrier region is adapted to prevent a diffusion of the first electrically conductive material through the diffusion barrier region.

Claims

1. A structure fabrication method, comprising:

providing a first interlevel dielectric (ILD) layer; and

then

forming a first electrically conductive line, a second electrically conductive line, and a diffusion barrier region in the first ILD layer,

wherein the diffusion barrier region (i) physically isolates, (ii) electrically couples together, and (iii) are in direct physical contact with the first and second electrically conductive lines,

wherein the first and second electrically conductive lines each comprises at least a first electrically conductive material,

wherein the diffusion barrier region comprises at least a second electrically conductive material different from the first electrically conductive material, and

wherein the diffusion barrier region is adapted to prevent a diffusion of the first electrically conductive material through the diffusion barrier region.

2. The method of claim 1, further comprising:

forming a second ILD layer on top of the first ILD layer after said forming the first and second electrically conductive lines and the diffusion barrier region is performed; and

then

forming an electrically conductive via in the second conductive ILD layer, wherein the electrically conductive via is electrically coupled to the first electrically conductive line, the second electrically conductive line, and the diffusion barrier region.

3. The method of claim 2, wherein the electrically conductive via is on top of and in direct physical contact with the diffusion barrier region.

4. The method of claim 2, wherein the electrically conductive via is on top of and in direct physical contact with the first electrically conductive line.

5. The method of claim 4,

wherein the electrically conductive via comprises a first region and a second region,

wherein the first region comprises the first electrically conductive material,

wherein the second region comprises the second electrically conductive material, and

wherein the second region (i) is in direct physical contact with the first region and the first electrically conductive line and (ii) physically isolates the first region and the first electrically conductive line.

6. The method of claim 4,

wherein the electrically conductive via comprise the first electrically conductive material, and

wherein the electrically conductive via does not comprise the second electrically conductive material.

7. The method of claim 1, wherein the first electrically conductive material comprises copper.

8. The method of claim 1, wherein the second electrically conductive material comprises tantalum nitride.