Method to resolve hollow metal defects in interconnects

• US 9,034,664 B2
• Filed: 05/16/2012
• Issued: 05/19/2015
• Est. Priority Date: 05/16/2012
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Bonilla, Griselda, Bao, Junjing, Choi, Samuel S., Filippi, Ronald G., Lustig, Naftali E., Simon, Andrew H.
• Primary Examiner(s): ZARNEKE, DAVID A
• Application Number:
  US13/472,555
• Publication Number:
  US 20130307151A1
• Time in Patent Office: 1,098 Days
• Field of Search: 438/4, 438/622, 438/618, 438/625, 438/629, 438/642, 438/652, 438/666
• US Class Current: 438/4
• CPC Class Codes: H01L 21/76832 Multiple layers
• CPC Class Codes: H01L 21/76834 formation of thin insulating films on the sidewalls or on top of conductors H01L21/76831 takes precedence
• CPC Class Codes: H01L 21/76849 the layer being positioned on top of the main fill metal
• CPC Class Codes: H01L 23/5283 Cross-sectional geometry
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding 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 method of repairing hollow metal void defects in interconnects and resulting structures. After polishing interconnects, hollow metal void defects become visible. The locations of the defects are largely predictable. A repair method patterns a mask material to have openings over the interconnects (and, sometimes, the adjacent dielectric layer) where defects are likely to appear. A local metal cap is formed in the mask openings to repair the defect. A dielectric cap covers the local metal cap and any recesses formed in the adjacent dielectric layer.

Claims

1. The method of repairing an interconnect, the method comprising:

providing an interconnect having a void in a first portion of the interconnect

after providing the interconnect, forming a mask over the interconnect and over a dielectric layer adjacent the interconnect;

opening the mask over the first portion of the interconnect and over a portion of the dielectric layer adjacent the first portion of the interconnect thereby forming a recess in the portion of the dielectric layer;

after opening the mask, forming a local metal cap on the first portion of the interconnect such that the local metal cap at least partially fills the void in the first portion of the interconnect; and

after forming the local metal cap, forming a dielectric cap in contact with the mask layer.

2. The method of claim 1, wherein forming the local metal cap is by selective deposition.

3. The method of claim 1, wherein the local metal cap comprises cobalt.

4. The method of claim 1, wherein the dielectric cap a least partially fills the recess in the dielectric layer, and wherein the dielectric cap is above and in contact with the local metal cap.

5. The method of claim 1, wherein the dielectric cap comprises nitrogen.

6. The method of claim 1, wherein the mask and the dielectric cap are made of the same material.

7. The method of claim 1, further comprising forming a via above the interconnect wherein the via lands on the interconnect.

8. The method of claim 7, wherein the via at least partially lands on the local metal cap.