Ar-based si-rich oxynitride film for dual damascene and/or contact etch stop layer

• US 6,235,653 B1
• Filed: 06/04/1999
• Issued: 05/22/2001
• Est. Priority Date: 06/04/1999
• Status: Expired due to Term

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Cheng, Wen-Kung, Wang, Yin-Lang, Chiu, Yuan-Hung, Chien, Hung-Ju
• Primary Examiner(s): Elms, Richard
• Assistant Examiner(s): Smith, Bradley
• Application Number:
  US09/324,924
• Time in Patent Office: 718 Days
• Field of Search: 438/786, 438/788, 438/769, 438/763
• US Class Current: 438/788
• CPC Class Codes: H01L 21/02263 deposition from the gas or vapour phase
• CPC Class Codes: H01L 21/3145 formed by deposition from a gas or vapour
• CPC Class Codes: H01L 21/76807 for dual damascene structures
• CPC Class Codes: H01L 21/76829 characterised by the formation of thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or liner layers

Abstract

A new method of forming a plasma-enhanced silicon-rich oxynitride layer having improved uniformity across the wafer in terms of layer thickness, refractivity, and reflectivity by using argon as the inert carrier gas is described. A semiconductor substrate is provided which may include semiconductor device structures. An Argon-based silicon-rich oxynitride etch stop layer is deposited overlying the semiconductor substrate. An oxide layer is deposited overlying the Argon-based silicon-rich oxynitride etch stop layer. An opening is etched through the oxide layer stopping at the Argon-based silicon-rich oxynitride etch stop layer. Thereafter, the Argon-based silicon-rich oxynitride etch stop layer within the opening is removed. The opening is filled with a conducting layer. This Argon-based silicon-rich oxynitride layer has improved uniformity across the wafer in terms of layer thickness, refractivity, and reflectivity as compared with a helium-based silicon-rich oxynitride layer.

Claims

1. A method of fabricating an integrated circuit device comprising:

providing a semiconductor substrate;

depositing by plasma-enhanced chemical vapor deposition, using Argon as a radio frequency stabilizer and a carrier gas, a silicon-rich oxynitride etch stop layer overlying said semiconductor substrate;

depositing an oxide layer overlying said silicon-rich oxynitride etch stop layer;

etching an opening through said oxide layer stopping at said silicon-rich oxynitride etch stop layer;

thereafter removing said silicon-rich oxynitride etch stop layer within said opening;

filling said opening with a conducting layer; and

completing said fabrication of said integrated circuit device.

2. The method according to claim 1 wherein said semiconductor substrate comprises semiconductor device structures including gate electrodes and associated source and drain regions formed in and on a silicon substrate.

3. The method according to claim 1 wherein said silicon-rich oxynitride etch stop layer is deposited by flowing SiH₄ at 30 to 150 sccm, flowing N₂O at 20 to 100 sccm, and flowing Argon at 500 to 3000 sccm under pressure of 2 to 8 torr, radio frequency (RF) power of 50 to 150 watts, and temperature of 300 to 500°

C. to form a film having a thickness of between about 200 and 1000 Angstroms.

4. The method according to claim 1 wherein said silicon-rich oxynitride etch stop layer is deposited by flowing SiH₄ at 80 sccm, flowing N₂O at 35 sccm, and flowing Argon at 1900 sccm under pressure of 5 torr, radio frequency (RF) power of 80 watts, and temperature of 400°

C. to form a film having a thickness of about 400 Angstroms.

5. The method according to claim 1 wherein said step of etching said opening through said oxide layer and said step of filling said opening comprises a contact etch process.

6. The method according to claim 1 wherein said step of etching said opening through said oxide layer and said step of filling said opening comprises a damascene process.

7. The method according to claim 1 wherein said silicon-rich oxynitride etch stop layer has an etch rate of about 300 Angstroms per minute.

8. The method according to claim 1 wherein said silicon-rich oxynitride etch stop layer has a maximum uniformity variability of less than 1.5% for refractive index variability, less than 2% for reflectivity index variability, and less than 1.5% for thickness variability.

9. A method of fabricating an intergrated circuit device comprising:

providing semiconductor device structures in and on a semiconductor substrate covered by an insulating layer;

depositing by plasma-enhanced chemical vapor deposition a first silicon-rich oxynitride etch stop layer overlying said insulating layer using Argon as a radio frequency stabilizer and a carrier gas;

depositing a first oxide layer overlaying said first silicon-rich oxynitride etch stop layer;

depositing by plasma-enhanced chemical vapor desposition a second silicon-rich oxynitride etch stop layer overlying said first oxide layer using Argon as a radio frequency stabilizer and a carrier gas;

despositing a second oxide layer overlying said second silicon-rich oxynide etch stop layer;

etching a dual damascene opening through said second and first oxide layers with etch stops at said second and first silicon-rich oxynitride etch stop layers and removing said second and first silicon-rich oxynitride etch stop layers within said dual damascene opening;

filling said dual damascene opening with a conducting layer; and

completing said fabricating of said intergrated circuit device.

10. The method according to claim 9 wherein said semiconductor device structures include gate electrodes and associated source and drain regions and first metallization layers.

11. The method according to claim 9 wherein said first and second silicon-rich oxynitride etch stop layers are deposited by flowing SiH₄ at 30 to 150 sccm, flowing N₂O at 20 to 100 sccm, and flowing Argon at 500 to 3000 sccm under pressure of 2 to 8 torr, radio frequency power of 50 to 150 watts, and temperature of 300 to 500°

C. to form a film having a thickness of between about 200 and 1000 Angstroms.

12. The method according to claim 9 wherein said silicon-rich oxynitride etch stop layer is deposited by flowing SiH₄ at 80 sccm, flowing N₂O at 35 sccm, and flowing Argon at 1900 sccm under pressure of 5 torr, radio frequency (RF) power of 80 watts, and temperature of 400°

C. to form a film having a thickness of about 400 Angstroms.

13. The method according to claim 9 wherein said silicon-rich oxynitride etch stop layer has an etch rate of about 300 Angstroms per minute.

14. The method according to claim 9 wherein said silicon-rich oxynitride etch stop layer has a maximum uniformity variability of less than 1.5% for refractive index variability, less than 2% for reflectivity index variability, and less than 1.5% for thickness variability.

15. A method of fabricating an integrated circuit device comprising:

providing semiconductor device structures in and on a semiconductor substrate;

depositing by plasma-enhanced chemical vapor deposition a silicon-rich oxynitride etch stop layer overlying said semiconductor device structures using Argon as a radio frequency stabilizer and a carrier gas;

depositing an oxide layer overlying said silicon-rich oxynitride etch stop layer;

etching an opening through said oxide layer stopping at said silicon-rich oxynitride etch stop layer;

thereafter removing said silicon-rich oxynitride etch stop layer within said opening to expose one of said semiconductor device structures;

filling said opening with a conducting layer; and

completing said fabrication of said integrated circuit device.

16. The method according to claim 15 wherein said semiconductor device structures include gate electrodes and associated source and drain regions.

17. The method according to claim 15 wherein said silicon-rich oxynitride etch stop layer is deposited by flowing SiH₄ at 30 to 50 sccm, flowing N₂O at 20 to 100 sccm, and flowing Argon at 500 to 3000 sccm under pressure of 2 to 8 torr, power of 50 to 150 watts, and temperature of 300 to 500°

C. to form a film having a thickness of between about 200 and 1000 Angstroms.

18. The method according to claim 15 wherein said silicon-rich oxynitride etch stop layer is deposited by flowing SiH₄ at 80 sccm, flowing N₂O at 35 sccm, and flowing Argon at 1900 sccm under pressure of 5 torr, radio frequency (RF) power of 80 watts, and temperature of 400°

C. to form a film having a thickness of about 400 Angstroms.

19. The method according to claim 15 wherein said silicon-rich oxynitride etch stop layer has an etch rate of about 300 Angstroms per minute.

20. The method according to claim 15 wherein said silicon-rich oxynitride etch stop layer has a maximum uniformity variability of less than 1.5% for refractive index variability, less than 2% for reflectivity index variability, and less than 1.5% for thickness variability.