Manufacture method of metal bottom ARC

• US 6,573,189 B1
• Filed: 11/07/2001
• Issued: 06/03/2003
• Est. Priority Date: 11/07/2001
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Yu, Ming-Hua, Wu, Szu-An, Lin, Shih-Chi
• Primary Examiner(s): GOUDREAU, GEORGE A
• Application Number:
  US10/044,859
• Time in Patent Office: 573 Days
• Field of Search: 430/5, 438/725, 438/717, 438/736, 427/569
• US Class Current: 438/725
• CPC Class Codes: H01L 21/0276 using an anti-reflective coating anti-reflective coating for lithography in general G03F7/09

Abstract

A new method of preventing photoresist footing by forming a silicon oxynitride ARC layer having an oxygen-rich surface is described. An insulating layer is provided on a substrate. A metal layer is deposited overlying the insulating layer. A silicon oxynitride antireflective coating layer having an oxygen-rich surface is deposited overlying the metal layer. A photoresist mask is formed overlying the antireflective coating layer wherein the antireflective coating layer prevents photoresist footing. The antireflective coating layer and the metal layer are etched away where they are not covered by the photoresist mask to complete formation of metal lines in the fabrication of an integrated circuit.

Claims

1. A method of forming metal lines in the fabrication of an integrated circuit comprising:

providing an insulating layer on a substrate;

depositing a metal layer overlying substrate;

depositing an antireflective coating layer overlying said metal layer wherein said as deposited antireflective coating layer has an oxygen-rich top surface layer wherein said oxygen-rich top surface layer has a higher oxygen content than a remainder of said antireflective coating layer;

forming a photoresist mask overlying said antireflective coating layer; and

etching away said antireflective coating layer and said metal layer where they are not covered by said photoresist mask to complete formation of said metal lines in said fabrication of said integrated circuit.

2. The method according to claim 1 wherein said insulating layer covers semiconductor device structures in and on said substrate wherein said semiconductor device structures include gate electrodes and source and drain regions.

3. The method according to claim 1 further comprising depositing a barrier layer underlying said metal layer.

4. The method according to claim 1 wherein said metal layer is selected from the group containing:

aluminum and AlCu having a thickness of between about 4000 and 8000 Angstroms.

5. The method according to claim 1 wherein said step of depositing said antireflective coating layer comprises:

flowing SiH₄ at between about 50 and 65 sccm and flowing N₂O at between about 85 and 95 sccm for between about 10 and 12 seconds to form a silicon oxynitride layer; and

thereafter flowing SiH₄ at between about 5 and 20 sccm and flowing N₂O at between about 400 and 500 sccm for between about 3 and 5 seconds to form said oxygen-rich surface of said silicon oxynitride layer.

6. The method according to claim 1 wherein said antireflective coating layer having said oxygen-rich surface prevents footing of said photoresist mask.

7. A method of forming metal lines in the fabrication of an integrated circuit comprising:

providing an insulating layer on a substrate;

depositing a metal layer overlying substrate;

depositing a silicon oxynitride antireflective coating layer overlying said metal layer wherein said as deposited silicon oxynitride antireflective coating layer has an oxygen-rich top surface layer wherein said oxygen-rich top surface layer has a higher oxygen content than a remainder of said silicon oxynitride antireflective coating layer;

forming a photoresist mask overlying said antireflective coating layer; and

etching away said antireflective coating layer and said metal layer where they are not covered by said photoresist mask to complete formation of said metal lines in said fabrication of said integrated circuit.

8. The method according to claim 7 wherein said insulating layer covers semiconductor device structures in and on said substrate wherein said semiconductor device structures include gate electrodes and source and drain regions.

9. The method according to claim 7 further comprising depositing a barrier layer underlying said metal layer.

10. The method according to claim 7 wherein said metal layer is selected from the group containing:

aluminum and AlCu having a thickness of between about 4000 and 8000 Angstroms.

11. The method according to claim 7 wherein said step of depositing said antireflective coating layer comprises:

flowing SiH₄ at between about 50 and 65 sccm and flowing N₂O at between about 85 and 95 sccm for between about 10 and 12 seconds to form a silicon oxynitride layer; and

thereafter flowing SiH₄ at between about 5 and 20 sccm and flowing N₂O at between about 400 and 500 sccm for between about 3 and 5 seconds to form said oxygen-rich surface of said silicon oxynitride layer.

12. The method according to claim 7 wherein said antireflective coating layer having said oxygen-rich surface prevents footing of said photoresist mask.

13. A method of forming metal lines in the fabrication of an integrated circuit comprising:

providing an insulating layer on a substrate;

depositing a metal layer overlying substrate;

depositing a silicon oxynitride antireflective coating layer overlying said metal layer wherein said as deposited silicon nitride antireflective coating layer has an oxygen-rich top surface layer wherein said oxygen-rich top surface layer has a higher oxygen content than a remainder of said silicon oxynitride antireflective coating layer;

forming a photoresist mask overlying said antireflective coating layer wherein said antireflective coating layer prevents footing of said photoresist mask; and

etching away said antireflective coating layer and said metal layer where they are not covered by said photoresist mask to complete formation of said metal lines in said fabrication of said integrated circuit.

14. The method according to claim 13 wherein said insulating layer covers semiconductor device structures in and on said substrate wherein said semiconductor device structures include gate electrodes and source and drain regions.

15. The method according to claim 13 further comprising depositing a barrier layer underlying said metal layer.

16. The method according to claim 13 wherein said metal layer is selected from the group containing:

aluminum and AlCu having a thickness of between about 4000 and 8000 Angstroms.

17. The method according to claim 13 wherein said step of depositing said antireflective coating layer comprises:

flowing SiH₄ at between about 50 and 65 sccm and flowing N₂O at between about 85 and 95 sccm for between about 10 and 12 seconds to form a silicon oxynitride layer; and

thereafter flowing SiH₄ at between about 5 and 20 sccm and flowing N₂O at between about 400 and 500 sccm for between about 3 and 5 seconds to form said oxygen-rich surface of said silicon oxynitride layer.