Method of forming copper wire on semiconductor device

• US 6,878,617 B2
• Filed: 12/30/2002
• Issued: 04/12/2005
• Est. Priority Date: 05/16/2002
• Status: Expired due to Term

• Current Assignee: Chung Cheng Holdings LLC (Intellectual Ventures LLC)
• Original Assignee: Hynix Semiconductor Incorporated (SK Hynix Inc.)
• Inventors: Kim, Hyun Yong, Lee, Byung Zu
• Primary Examiner(s): Smith, Matthew
• Assistant Examiner(s): LUU, CHUONG A
• Application Number:
  US10/331,428
• Publication Number:
  US 20030216040A1
• Time in Patent Office: 834 Days
• Field of Search: 438/637, 438/638, 438/645, 438/687, 438/629, 438/634, 438/625, 438/620
• US Class Current: 438/625
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/76849 the layer being positioned on top of the main fill metal
• CPC Class Codes: H01L 21/76879 by selective deposition of conductive material in the vias, e.g. selective C.V.D. on semiconductor material, plating plating on semiconductors in general H01L21/288

Abstract

Disclosed is a method of forming a copper wire on a semiconductor device capable of preventing the natural oxidation of copper. The method comprises the steps of: forming an insulation film pattern having vias and trenches on a semiconductor substrate; forming a copper wire by filling up the vias and the trenches with copper; successively forming a capping layer and a protective layer on the copper wire and the insulation film pattern; exposing the copper wire by selectively removing the capping layer and the protective layer; and forming an oxidation-prevention layer on the copper wire. According to the present invention, the natural oxidation of copper is avoided by selectively depositing aluminum on a copper wire pad, and therefore a dependable evaluation is possible from tests of reliability in a high temperature. Furthermore, since aluminum has a lower contact resistance compared with copper, dependable test results are obtained during tests of electrical characteristics.

Claims

1. A method of forming a copper wire on a semiconductor device, comprising the steps of:

forming an insulation film pattern having vias and trenches on a semiconductor substrate;

forming a copper wire by filling up the vias and the trenches with copper;

successively forming a capping layer and a protective layer on the copper wire and the insulation film pattern;

exposing the copper wire by selectively removing the capping layer and the protective layer;

forming an aluminum layer as an oxidation-prevention layer on the copper wire; and

removing the natural oxidation layer on the copper wire.

2. The method as claimed in claim 1,

wherein during the step of removing the natural oxidation layer, a solution of 5%-10% HF is used.

3. The method as claimed in claim 1, wherein the aluminum layer is formed by a chemical vapor deposition method using dimethylaluminumhydride as a precursor.

4. The method as claimed in claim 3, wherein the aluminum layer is deposited it a temperature of 230°

C. to 350°

C. and formed to a thickness of 5,000 Å

to 10,000 Å

.

5. The method as claimed in claim 1, further comprising the step of:

performing a heat treatment for stabilizing the structure of the oxidation-prevention layer, after the step of forming the oxidation-prevention layer.

6. The method as claimed in claim 5, wherein the heat treatment is performed for 10 to 30 minutes at a temperature of 200°

C. to 400°

C.