Method for preventing a metal corrosion in a semiconductor device

• US 20060019492A1
• Filed: 07/11/2005
• Published: 01/26/2006
• Est. Priority Date: 07/20/2004
• Status: Active Grant

• Current Assignee: DONGBU ELECTRONICS CO., LTD. (DB HiTek Co., Ltd.)
• Original Assignee: Dongbuanam Semiconductor, Inc. (DB HiTek Co., Ltd.)
• Inventors: Lee, Jae Suk
• Granted Patent: US 7,468,319 B2
• Time in Patent Office: Days
• US Class Current: 438/652
• CPC Class Codes: H01L 21/02071 the processing being a delineation, e.g. RIE, of conductive layers
• CPC Class Codes: H01L 21/31138 by dry-etching
• CPC Class Codes: H01L 21/32136 using plasmas
• CPC Class Codes: H01L 21/76888 By rendering at least a portion of the conductor non conductive, e.g. oxidation

Abstract

The present invention relates to a method for preventing a metal corrosion in a semiconductor device. The present method includes the steps of etching of a metal layer in a chamber, the metal layer having a photoresist pattern thereon or thereover; oxidizing a surface of the metal layer using a plasma comprising N₂O in the same chamber; and removing the photoresist. Therefore, metal corrosion as well as bridges between metal wirings can be suppressed or prevented, thereby improving the profile of metal layer and the reliability and yield of the semiconductor device.

Claims

1. A method for preventing metal corrosion in a semiconductor or integrated circuit, comprising the steps of:

etching a metal layer in a chamber, the metal layer having a photoresist pattern thereon or thereover;

oxidizing a surface of the metal layer using a plasma comprising N₂O in the chamber; and

removing the photoresist.

2. The method of claim 1, further comprising the step of removing a portion of an oxidized metal by sputter etching with an inert gas, after the step of oxidizing the surface of the metal layer.

3. The method of claim 2, wherein the inert gas includes at least one member of the group consisting of He, Ne, Ar, Kr, Xe and Rn.

4. The method of claim 2, wherein the sputter etching step also removes a portion of an oxide layer under said metal layer and exposed by said etching step.

5. The method of claim 2, wherein the sputter etching step is also performed in the chamber.

6. The method of claim 1, wherein the metal layer comprises one or more aluminum layers consisting essentially of aluminum or aluminum alloy.

7. The method of claim 6, wherein the one or more aluminum layers consists essentially of an aluminum alloy selected from the group consisting of aluminum-copper, aluminum-titanium, and aluminum-silicon alloys.

8. The method of claim 6, wherein the aluminum alloy is selected from the group consisting of aluminum-copper and aluminum-copper-silicon alloys.

9. The method of claim 6, wherein the metal layer further comprises one or more barrier layers.

10. The method of claim 9, wherein the one or more barrier layers comprises a Ti, TiN, W or TiW layer.

11. The method of claim 10, wherein the one or more barrier layers comprises a Ti/TiN bilayer.

12. The method of claim 6, wherein the metal layer further comprises an antireflective coating.

13. The method of claim 12, wherein the antireflective coating comprises a TiN layer.

14. The method of claim 12, wherein the antireflective coating comprises a Ti/TiN bilayer.

15. The method of claim 1, wherein etching the metal layer comprises dry etching with a plasma comprising chlorine.

16. The method of claim 14, wherein the dry etching comprises reactive ion etching (RIE).

17. The method of claim 1, wherein the metal layer has a width 50 to 150 Å

greater than a desired or predetermined critical dimension after the metal layer is etched.

18. The method of claim 1, wherein the oxidized metal surface has a width of from 50 to 150 Å

.

19. The method of claim 1, wherein the step of removing the photoresist comprises ashing with a plasma comprising a chlorine source gas and a hydrofluorocarbon gas.

20. The method of claim 1, wherein the step of removing the photoresist comprises ashing with a plasma comprising Cl₂ and CHF₃ gases.