Passivated copper surfaces

• US 6,323,131 B1
• Filed: 06/13/1998
• Issued: 11/27/2001
• Est. Priority Date: 06/13/1998
• Status: Expired due to Term

• Current Assignee: Bell Semiconductor, LLC (Hilco Inc. (d/b/a Hilco Global))
• Original Assignee: Agere Systems Guardian Corp. (Broadcom, Inc.)
• Inventors: Obeng, Yaw Samuel, Obeng, Jennifer S.
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): Rao, Shrinivas H.
• Application Number:
  US09/096,998
• Time in Patent Office: 1,263 Days
• Field of Search: 438/687, 428/418, 428/425.8, 428/450, 428/457
• US Class Current: 438/687
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H01L 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76829 characterised by the formation of thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or liner layers
• CPC Class Codes: H01L 21/76831 in via holes or trenches, e.g. non-conductive sidewall liners
• 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 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
• CPC Class Codes: Y10T 428/31529 Next to metal
• CPC Class Codes: Y10T 428/31605 Next to free metal

Abstract

A ULSI circuit chip comprising copper interconnects is provided with a corrosion protection passivating layer on the surface of the copper which layer is comprised of a self assembled organic monolayer formed from treating the copper surface with a dilute solution of, for example a thio-bisalkyl acetoacetonate. A similar layer can be formed under the copper to provide a barrier layer against copper migration.

Claims

1. An article of manufacture comprising a protective film located over the metallic copper layer and that includes a self assembled organic compound, said protective film comprising a compound having the formula X[(CH₂(CH₂)_n—

O—

C(O)CH₂C(O)CH₃]₂ where X is S, Si, or N and n is from 2 to 6.

2. The article set forth in claim 1 wherein said film further comprises a surface sealing component.

3. The article set forth in claim 2 wherein said surface sealing component is selected from the group consisting of:

surfactant thiols represented by the formula C_nH_2n+1SH where n is from 6 to 18;

alkyl amines wherein the alkyl group contains from 4 to 20 carbon atoms; and

aliphatic silanes selected from the an n-alkyl trichlorosilane wherein the alkyl group contains from 6 to 20 carbon atoms.

4. The article set forth in claim 1 wherein said film is a mono-layer.

9. The article set forth in claim 1 wherein said self assembled organic compound is selected from the group consisting of:

a long alkyl chain silane;

a carboxylic acid; and

a thiol.

5. A high density integrated circuit having copper interconnects comprising a protective film located over the metallic copper layer and that includes a self assembled organic passivating film on the surface of said copper interconnects, said protective film comprising a compound having the formula X[(CH₂(CH₂)_n—

O—

C(O)CH₂C(O)CH₃]₂ where X is S, Si, or N and n is from 2 to 6.

6. The integrated circuit set forth in claim 5 wherein said film further comprises a surface sealing component.

7. The integrated circuit set forth in claim 6 wherein said surface sealing component is selected from the group consisting of:

surfactant thiols represented by the formula C_nH_2n+1SH where n is from 6 to 18;

alkyl amines wherein the alkyl group contains from 4 to 20 carbon atoms; and

aliphatic silanes selected from the an n-alkyl trichlorosilane wherein the alkyl group contains from 6 to 20 carbon atoms.

8. The integrated circuit set forth in claim 5 further comprising a barrier layer underlying said copper interconnects, said barrier layer consisting essentially of a self-assembled organic film.