Method of manufracturing increasing reliability of copper-based metallization structures in a microstructure device by using aluminum nitride

• US 7,829,460 B2
• Filed: 11/30/2007
• Issued: 11/09/2010
• Est. Priority Date: 01/31/2007
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: GlobalFoundries, Inc.
• Inventors: Kahlert, Volker, Streck, Christof
• Primary Examiner(s): LE, DUNG ANH
• Application Number:
  US11/948,245
• Publication Number:
  US 20080179741A1
• Time in Patent Office: 1,075 Days
• Field of Search: 438/627, 438/643, 438/653, 438618-624, 75672-674
• US Class Current: 438/653
• CPC Class Codes: C23C 16/303 Nitrides
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/318 composed of nitrides
• 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 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

Abstract

By forming an aluminum nitride layer by a self-limiting process sequence, the interface characteristics of a copper-based metallization layer may be significantly enhanced while nevertheless maintaining the overall permittivity of the layer stack at a lower level.

Claims

1. A method, comprising:

forming a nitrogen-containing layer on an exposed surface of a metal region formed in a dielectric layer; and

exposing said nitrogen-containing layer to an ambient established on the basis of an aluminum-containing gas to form an aluminum and nitrogen-containing first barrier layer on said metal region.

2. The method of claim 1, wherein said metal region comprises copper.

3. The method of claim 2, wherein forming said nitrogen-containing layer comprises treating said exposed surface to convert copper oxide into copper nitride.

4. The method of claim 3, wherein treating said exposed surface comprises establishing an ammonium (NH₃) containing ambient.

5. The method of claim 1, wherein said aluminum-containing gas comprises Al(CH₃)₃.

6. The method of claim 1, further comprising forming a second dielectric barrier layer on said first barrier layer and forming a low-k dielectric material above said second dielectric barrier layer.

7. The method of claim 6, wherein said first barrier layer and said second dielectric layer are formed in an in situ process.

8. The method of claim 3, wherein treating said exposed surface comprises thermal activation in the absence of a plasma.

9. The method of claim 1, further comprising forming a low-k dielectric material on said aluminum and nitrogen-containing first barrier layer.

10. The method of claim 3, further comprising forming said copper oxide in an oxidizing ambient as a substantially continuous copper oxide layer.

11. The method of claim 1, wherein said aluminum and nitrogen-containing first barrier layer is formed on said dielectric layer.

12. The method of claim 11, further comprising forming said dielectric layer so as to have OH groups at least at a surface thereof.