Accelerated plasma clean

• US 6,374,831 B1
• Filed: 02/04/1999
• Issued: 04/23/2002
• Est. Priority Date: 02/04/1999
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Chandran, Shankar N., Venkataraman, Shankar, Yieh, Ellie, Jones, Gwendolyn D., Hendrickson, Scott
• Primary Examiner(s): Markoff, Alexander
• Application Number:
  US09/246,036
• Time in Patent Office: 1,174 Days
• Field of Search: 136/1, 136/1.1, 136/1.2, 136/1.3, 136/22.1, 136/22.18, 136/22.19, 136/902, 156/345, 348/905
• US Class Current: 134/1.1
• CPC Class Codes: C23C 16/4405 Cleaning of reactor or parts inside the reactor by using reactive gases
• CPC Class Codes: Y10S 134/902 Semiconductor wafer
• CPC Class Codes: Y10S 438/905 Cleaning of reaction chamber

Abstract

A method and apparatus that reduces the time required to clean a processing chamber employing a reactive plasma cleaning process. A plasma is formed in an Astron fluorine source generator from a flow of substantially pure inert-source gas. After formation of the plasma, a flow of a fluorine source gas is introduced therein such that the fluorine source flow accelerates at a rate no greater than 1.67 standard cubic centimeters per second² (scc/s₂). In this fashion, the plasma contains a plurality of radicals and dissociated inert-source gas atoms, defining a cleaning mixture. The ratio of inert-source gas to fluorine source is greater than 1:1.

Claims

1. A method for removing residue from a substrate processing system, said system having a remote plasma chamber and a substrate processing chamber in fluid communication, said method comprising:

flowing into said remote plasma chamber, a first gas consisting essentially of inert gas at a first rate;

forming a plasma from said first gas;

moving, into said plasma, a flow of a fluorine source gas at a second rate, thereby creating a plurality of reactive radicals therefrom;

increasing said second rate, with said plasma and said reactive radicals defining a cleaning mixture; and

introducing said cleaning mixture into said substrate processing chamber.

2. The method as recited in claim 1 wherein said increasing step includes increasing said first rate while said second rate is increased.

3. The method as recited in claim 1 wherein said increasing step includes accelerating said fluorine source at said predetermined rate, with said predetermined rate being no greater than 1.67 standard cubic centimeters per second².

4. The method as recited in claim 1 wherein said first rate is greater than said second rate.

5. The method as recited in claim 1 wherein said first and second rates are established to maintain, within said remote plasma chamber, a predefined ratio of said inert-source gas to said fluorine source gas.

6. The method as recited in claim 1 wherein said fluorine source gas consists essentially of a gas selected from the group of NF₃, F₂, CF₄, C₂F₆, C₃F₈, SF₆, and ClF₃.

7. The method as recited in claim 1 wherein said first gas includes argon.

8. The method as recited in claim 5 wherein said predefined ratio is greater than 3:

2.

9. The method of claim 1 wherein said plasma in said remote plasma chamber is formed by a toroidal plasma source.

10. A method of removing residue from a substrate processing system, said system having a remote plasma chamber and a substrate processing chamber in fluid communication, said method comprising:

flowing into said remote plasma chamber, a first gas consisting essentially of inert gas at a first rate;

forming a plasma from said first gas;

moving, into said plasma, a flow of a fluorine source gas at a second rate, thereby creating a plurality of reactive radicals therefrom, with said first and second rates established to maintain, within said remote plasma chamber, a predetermined ratio of said first gas to said fluorine source gas, with said predetermined ratio being greater than 1;

1;

increasing both said first and second rates, with said plasma and said reactive radicals defining a cleaning mixture, while maintaining said ratio greater than 1;

1; and

introducing said cleaning mixture into said substrate processing chamber.

11. The method as recited in claim 10 wherein said predetermined ratio is greater than 3:

2.

12. The method as recited in claim 10 wherein said increasing steps includes increasing said first rate to 16.67 scc/s and increasing said second rate to 13.33 scc/s.

13. The method as recited in claim 10 wherein said fluorine source gas consists essentially of a gas selected from the group of NF₃, F₂, CF₄, C₂F₆, C₃F₈, SF₆, and ClF₃.

14. The method as recited in claim 10 wherein said first gas includes argon.

15. The method of claim 10 wherein said plasma in said remote plasma chamber is formed by a toroidal plasma source.