Cleaning of multicompositional etchant residues

• US 20020117472A1
• Filed: 02/23/2001
• Published: 08/29/2002
• Est. Priority Date: 02/23/2001
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Huang, Tuo-Chuan, Sun, Zhi-Wen, Jiang, Anbei
• Granted Patent: US 6,852,242 B2
• Time in Patent Office: Days
• US Class Current: 216/68
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01J 37/32449 Gas control, e.g. control of the gas flow
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01L 21/02046 Dry cleaning only H01L21/02085 takes precedence

Abstract

A substrate processing apparatus has a chamber with a substrate transport to transport a substrate onto a substrate support in the chamber, a gas supply to provide a gas in the chamber, a gas energizer to energize the gas, and a gas exhaust to exhaust the gas. A controller operates one or more of the substrate support, gas supply, gas energizer, and gas exhaust, to set etching process conditions in the chamber to etch a plurality of substrates, thereby depositing etchant residues on surfaces in the chamber. The controller also operates one or more of the substrate support, gas supply, gas energizer, and gas exhaust, to set cleaning process conditions in the chamber to clean the etchant residues. The cleaning process conditions comprise a volumetric flow ratio of O₂ to CF₄ of from about 1:1 to about 1:40.

Claims

1. A substrate processing apparatus comprising:

a chamber comprising a substrate transport to transport a substrate onto a substrate support in the chamber, a gas supply to provide a gas in the chamber, a gas energizer to energize the gas, and a gas exhaust to exhaust the gas;

a controller to operate the substrate support, gas supply, gas energizer, and gas exhaust, to set (i) etching process conditions in the chamber to etch a plurality of substrates, thereby depositing etchant residues on surfaces in the chamber, and (ii) cleaning process conditions in the chamber to clean the etchant residues, the process conditions comprising a volumetric flow ratio of O₂ to CF₄ of from about 1;

1 to about 1;

40.

2. An apparatus according to claim 1 wherein the controller is adapted to set etching process conditions to etch first substrates comprising a first material and second substrates comprising a second material.

3. An apparatus according to claim 2 wherein the etching process conditions comprise providing a first etchant gas to etch the first substrates and providing a second etchant gas to etch the second substrates.

4. An apparatus according to claim 2 wherein the first and second materials comprise one or more of silicon, silicon oxide, polycide, polysilicon, tungsten silicide, titanium silicide and resist.

5. An apparatus according to claim 1 wherein the controller is adapted to control the operation of the chamber to process one or sacrificial substrates in the chamber after etching of the plurality of substrates.

6. An apparatus according to claim 5 wherein the controller is adapted to provide an energized gas in the chamber to etch the sacrificial substrates and deposit a sacrificial coating on surfaces in the chamber.

7. An apparatus according to claim 1 wherein the controller is adapted to set a volumetric flow ratio of O₂ to CF₄ of from about 1:

2 to about 1;

8.

8. An apparatus according to claim 1 wherein the cleaning process conditions comprise an RF power level applied to an antenna about the chamber, and the controller is adapted to apply the RF power level to the antenna at from about 200 to about 1500 Watts.

9. An apparatus according to claim 1 wherein the cleaning process conditions comprise a bias power level applied to an electrode in the chamber, and the controller is adapted to apply a bias power level to the electrode of less than about 40 Watts.

10. An apparatus according to claim 1 wherein the cleaning process conditions comprise a pressure of the cleaning gas in the chamber, and the controller is adapted to maintain the pressure of the cleaning gas in the chamber at from about 5 mTorr to about 40 mTorr.

11. An apparatus according to claim 1 comprising a detector adapted to monitor an intensity of a radiation emission at a wavelength of about 4405 Å

from the energized gas in the chamber and send a signal to the controller, and wherein the controller is adapted to determine a cleaning process endpoint from the signal.

13. A method according to claim 12 wherein (a) comprises etching first substrates comprising a first material and second substrates comprising a second material.

14. A method according to claim 13 comprising providing a first etchant gas to etch the first substrates and a second etchant gas to etch the second substrates.

15. A method according to claim 13 wherein the first and second materials comprise one or more of silicon, silicon oxide, polycide, polysilicon, tungsten silicide, titanium silicide and photoresist.

16. A method according to claim 12 comprising processing one or more sacrificial substrates in the chamber after etching of the plurality of substrates.

17. A method according to claim 16 comprising providing an energized gas in the chamber to etch the sacrificial substrates and deposit a sacrificial coating on surfaces in the chamber.

18. A method according to claim 12 wherein the volumetric flow ratio of O₂ to CF₄ is from about 1:

2 to about 1;

8.

19. A method according to claim 12 wherein (b) comprises applying an RF power level of from about 200 to about 1500 Watts to an antenna about the chamber.

20. A method according to claim 12 wherein (b) comprises applying a bias power level of less than about 40 Watts to an electrode in the chamber.

21. A method according to claim 12 wherein (b) comprises maintaining the pressure in the chamber at from about 5 mTorr to about 40 mTorr.

22. A method according to claim 12 wherein (b) further comprises monitoring an intensity of a radiation emission from the energized gas in the chamber at a wavelength of about 4405 Å

to determine a cleaning process endpoint.

24. An apparatus according to claim 23 wherein the controller is adapted to set etching process conditions to etch first substrates comprising a first material ans second substrates comprising a second material.

25. An apparatus according to claim 24 wherein the etching process conditions comprise providing a first etchant gas to etch the first substrates, and a second etchant gas to etch the second substrates

26. An apparatus according to claim 23 wherein the controller is adapted to set sacrificial substrate processing conditions to provide an energized gas in the chamber to etch the sacrificial substrates.

27. An apparatus according to claim 26 wherein the sacrificial substrates comprise silicon.

28. An apparatus according to claim 23 wherein the controller is adapted to set a volumetric flow ratio of O₂ to CF₄ of from about 1:

1 to about 1;

40.

30. A method according to claim 29 wherein (a) comprises etching first substrates comprising a first material and etching second substrates comprising a second material.

31. A method according to claim 30 comprising providing a first etchant gas to etch the first substrates and a second etchant gas to etch the second substrates.

32. A method according to claim 29 wherein (b) comprises the providing an energized gas in the chamber to etch the sacrificial substrates.

33. A method according to claim 32 wherein the sacrificial substrates comprise silicon.

34. A method according to claim 29 comprising setting a volumetric flow ratio of O₂ to CF₄ of from about 1:

1 to about 1;

40.

12. A method of processing substrates in a chamber, the method comprising:

(a) etching a plurality of substrates in the chamber, thereby depositing etchant residues on surfaces in the chamber; and

(b) cleaning the etchant residues by (i) introducing a cleaning gas comprising O₂ and CF₄ into the chamber, the volumetric flow ratio of O₂ to CF₄ being from about 1;

1 to about 1;

40, (ii) energizing the cleaning gas, and (iii) exhausting the cleaning gas from the chamber.

23. A substrate etching apparatus comprising:

a chamber comprising a substrate transport to transport a substrate onto a substrate support in the chamber, a gas supply to provide a gas in the chamber, a gas energizer to energize the gas, and a gas exhaust to exhaust the gas;

a controller to operate the substrate support, gas supply, gas energizer, and gas exhaust, to set (i) etching process conditions in the chamber to etch a plurality substrates, thereby depositing etchant residues on surfaces in the chamber (ii) sacrificial substrate processing conditions to process one or more sacrificial substrates in the chamber, thereby depositing a sacrificial coating on surfaces in the chamber, and (ii) cleaning process conditions in the chamber to clean the etchant residues and sacrificial coating, the process conditions comprising a volumetric flow ratio of O₂ to CF₄.

29. A method of etching substrates in a chamber, the method comprising:

(a) etching a plurality substrates in the chamber, thereby depositing etchant residues on surfaces in the chamber;

(b) processing one or more sacrificial substrates in the chamber, thereby depositing a sacrificial coating on surfaces in the chamber; and

(c) cleaning the etchant residues and sacrificial coating by (i) introducing a cleaning gas comprising O₂ and CF₄ into the chamber, (ii) energizing the cleaning gas, and (iii) exhausting the cleaning gas from the chamber.