Copper electroplating

• US 6,610,192 B1
• Filed: 11/02/2001
• Issued: 08/26/2003
• Est. Priority Date: 11/02/2000
• Status: Active Grant

• Current Assignee: Shipley Company, LLC (Dow, Inc.)
• Original Assignee: Shipley Company, LLC (Dow, Inc.)
• Inventors: Step, Eugene N., Binstead, Robert A., Morrissey, Denis
• Primary Examiner(s): Wong, Edna
• Application Number:
  US10/002,281
• Time in Patent Office: 662 Days
• Field of Search: 205/297, 205/298
• US Class Current: 205/297
• CPC Class Codes: C25D 3/38 of copper
• CPC Class Codes: C25D 7/123 Semiconductors first coated with a seed layer or a conductive layer
• CPC Class Codes: H05K 3/423 characterised by electroplating method

Abstract

Disclosed are compositions and methods for providing a planarized metal layer on a substrate having small apertures. The compositions and methods of the present invention provide complete fill of small apertures with reduced void formation.

Claims

1. A method of electroplating copper on an integrated circuit substrate having ≦

2 μ

m apertures comprising the steps of contacting the substrate to be plated with a copper electroplating bath comprising one or more leveling agents; and

subjecting the bath to a current density for a period of time sufficient to deposit a substantially planar copper layer on the substrate and fill the ≦

2 μ

m apertures without substantially forming defects in the ≦

2 μ

m apertures, wherein at least one leveling agent is a reaction product of a heterocyclic amine with an epihalohydrin.

2. The method of claim 1 wherein the leveling agent is present in an amount of from about 0.5 to about 50 ppm, based on the bath.

3. The method of claim 1 wherein the copper electroplating bath further comprises a source of halide ions.

4. The method of claim 1 wherein the copper electroplating bath further comprises an electrolyte selected from the group consisting of sulfuric acid, acetic acid, fluoroboric acid, alkylsulfonic acid, arylsulfonic acids, sulfamic acid, hydrochloric acid and phosphoric acid.

5. The method of claim 1 wherein the leveling agent is a reaction product of imidazole with epichlorohydrin.

6. A method of manufacturing an integrated circuit comprising the steps of contacting an integrated circuit substrate having ≦

2 μ

m apertures with a copper electroplating bath comprising one or more leveling agents; and

subjecting the bath to a current density for a period of time sufficient to deposit a substantially planar copper layer on the integrated circuit substrate and fill the ≦

2 μ

m apertures without substantially forming defects in the ≦

2 μ

m apertures, wherein at least one leveling agent is a reaction product of a heterocyclic amine with an epihalohydrin.

7. A method of reducing overplating in a copper layer of an integrated circuit device comprising the steps of contacting an integrated circuit substrate with a copper electroplating bath comprising one or more leveling agents;

and subjecting the bath to a current density for a period of time sufficient to deposit a substantially planar copper layer and fill ≦

2 μ

m apertures without substantially forming defects in the ≦

2 μ

m apertures, wherein at least one leveling agent is a reaction product of an amine with an epihalohydrin.

8. The method of claim 7 wherein the copper electroplating bath comprises one or more brighteners wherein the brightener is present in an amount of at least about 1 mg/L, based on the bath.

9. The method of claim 7 wherein the leveling agent is a reaction product of imidazole with epichlorohydrin.

10. A method of providing a copper layer having reduced overplating on an integrated circuit device comprising the steps of:

contacting an integrated circuit substrate comprising one or more apertures having a size of ≦

2 μ

m with a copper electroplating bath comprising electrolyte, one or more sources of copper ions, one or more brighteners and one or more leveling agents; and

subjecting the bath to a current density for a period of time sufficient to deposit a substantially planar copper layer and fill the ≦

2 μ

m apertures without substantially forming defects in the ≦

2 μ

m apertures;

wherein at least one leveling agent is a reaction product of a heterocyclic amine and an epihalohydrin.

11. The method of claim 10 wherein the leveling agent is present in an amount of from about 0.5 to about 50 ppm, based on the bath.

12. The method of claim 10 wherein the copper electroplating bath further comprises a source of halide ions.

13. The method of claim 10 wherein the electrolyte is selected from the group consisting of sulfuric acid, acetic acid, fluoroboric acid, alkylsulfonic acid, arylsulfonic acids, sulfamic acid, hydrochloric acid and phosphoric acid.

14. The method of claim 10 wherein the leveling agent is a reaction product of imidazole with epichlorohydrin.