Metal capping process and processing platform thereof

Patent metadata

Field	Value
Publication number	US-9487864-B2
Application number	US-201414155695-A
Country	US
Kind code	B2
Filing date	Jan 15, 2014
Priority date	Jan 15, 2014
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

Before depositing a metal capping layer on a metal interconnect in a damascene structure, a remote plasma is used to reduce native oxide formed on the metal interconnect. Accordingly, a remote plasma reducing chamber is integrated in a processing platform for depositing a metal capping layer.

First claim

What is claimed is:

1. A method of forming a metal capping layer on a metal interconnect, the method comprising:
embedding a copper interconnect in a substrate;
degassing the copper interconnect and the substrate under a non-oxidative gas at a pressure of 10 −3 -10 −8 Torr to decrease a thickness of a native oxide layer formed on the copper interconnect;
reducing the native oxide layer by a remote plasma generated by a reducing gas containing hydrogen; and
forming a cobalt capping layer on the copper interconnect.

2. The method of claim 1 , wherein the reducing gas is hydrogen gas or ammonium gas.

3. The method of claim 2 , wherein a plasma density of the remote plasma is 10 6 -10 13 cm −3 .

4. The method of claim 2 , wherein the reducing step is performed at a pressure of 10-1000 mTorr.

5. The method of claim 2 , wherein the reducing step is performed at a temperature of 25-400° C.

6. The method of claim 2 , wherein the reducing step is performed for 10 seconds to 10 minutes.

7. The method of claim 1 , wherein the cobalt layer is formed by a selective deposition method.

8. The method of claim 1 , wherein degassing the copper interconnect and the substrate is at a temperature of 200-400° C.

9. The method of claim 1 , wherein the non-oxidative gas is argon or hydrogen.

10. A method of forming a metal capping layer on metal interconnects, the method comprising:
embedding metal interconnects in a wafer;
degassing the wafer and the metal interconnects to decrease a thickness of native oxide formed on the metal interconnects under a non-oxidative gas at a pressure of 10 −3 -10 −8 Torr in a degassing chamber;
reducing the native oxide by a remote plasma in a remote plasma reducing chamber of a processing platform; and
depositing a metal capping layer on the reduced metal interconnects in a chemical vapor deposition chamber of the processing platform.

11. The method of claim 10 , wherein a source gas of the remote plasma is hydrogen or ammonium.

12. The method of claim 11 , wherein a plasma density of the remote plasma is 10 6 -10 13 cm −3 .

13. The method of claim 11 , wherein the reducing step is performed at a pressure of 10-1000 mTorr.

14. The method of claim 11 , wherein the reducing step is performed at a temperature of 25-400° C.

15. The method of claim 11 , wherein the reducing step is performed for 10 seconds to 10 minutes.

16. The method of claim 10 , wherein the metal interconnects are made from copper.

17. The method of claim 16 , wherein the metal capping layer is a cobalt layer.

18. The method of claim 17 , wherein the cobalt layer is formed by a selective deposition method.

19. The method of claim 10 , wherein the non-oxidative gas is argon or hydrogen.

20. The method of claim 10 , wherein degassing the wafer and the metal interconnects at a temperature of 200-400° C.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Chi Chih-Chien
• Tung Szu-Ping
• Huang Huang-Yi
• Hsieh Ching-Hua

Classifications

• H10P72/7602

  the wafers being placed on a robot blade or gripped by a gripper for conveyance · CPC title

• H10P72/0468 Primary

  comprising a chamber adapted to a particular process · CPC title

• H10P72/0466

  characterised by the construction of the load-lock chamber · CPC title

• H10P72/0461

  characterised by the presence of two or more transfer chambers · CPC title

• H10P70/277

  the processing being a planarisation of conductive layers · CPC title