Two step process for cleaning a substrate processing chamber

• US 6,068,729 A
• Filed: 09/03/1998
• Issued: 05/30/2000
• Est. Priority Date: 03/03/1997
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Shrotriya, Ashish V.
• Primary Examiner(s): Dang, Thi
• Assistant Examiner(s): ALEJANDRO MULERO, LUZ L
• Application Number:
  US09/145,923
• Time in Patent Office: 635 Days
• Field of Search: 134/1.1, 134/21, 156/345, 216/67, 438/710, 438/714, 438/905, 438/906, 438/963, 118/723 R
• US Class Current: 156/345.26
• CPC Class Codes: B08B 7/0035 by radiant energy, e.g. UV, laser, light beam or the like
• CPC Class Codes: C23C 16/4405 Cleaning of reactor or parts inside the reactor by using reactive gases
• CPC Class Codes: H01J 37/32862 In situ cleaning of vessels and/or internal parts
• CPC Class Codes: Y10S 438/905 Cleaning of reaction chamber

Abstract

A method and apparatus for removing particles from an interior surface of a processing chamber using a two-step cleaning process. The method includes introducing a first cleaning process gas into the processing chamber, applying energy to that first cleaning process gas to remove particles from the processing chamber'"'"'s interior surface, and introducing a second cleaning process gas into the processing chamber to remove a cleaning residue formed by a reaction between the first cleaning process gas and the processing chamber'"'"'s interior surface. Removing or gettering the cleaning residue from the chamber wall improves the quality of the wafers formed in the process.

Claims

1. A substrate processing system comprising:

a housing defining a chamber;

a gas distribution system adapted to introduce one or more gases into said chamber;

a plasma generation system operatively coupled to form a plasma within said chamber;

a controller for controlling said gas distribution system and said plasma generation system; and

a memory coupled to said controller comprising a computer readable medium having a computer readable program embodied therein for directing operation of said substrate processing system, said computer readable program comprising;

computer instructions that control said gas distribution system to flow a first cleaning process gas into said chamber, said first cleaning process gas comprising ozone and a fluorine-containing compound;

computer instructions that control said plasma generation system to form a plasma from said first cleaning process gas and maintain said plasma for a first time period;

computer instructions that control said gas distribution system to flow, after flowing said first cleaning process gas, a second cleaning process gas into said chamber, said second cleaning process gas comprising a compound selected from the group consisting of perfluorocarbons, fluorine, nitrogen, and combinations of fluorine and nitrogen; and

computer instructions that control said plasma generation system to form a plasma from said second cleaning process gas and maintain said plasma for a second time period.

2. The substrate processing system of claim 1, wherein:

said computer instructions that control said plasma generation system apply RF power at a level of between 0.99-3.95 W/cm ² when generating said plasma from said first cleaning process and apply RF power at a level of between about 0.79-3.95 W/cm ² when generating said plasma from said second cleaning process gas.

3. The substrate processing system of claim 2, wherein said second cleaning process gas comprises C₂ F₆.

4. The substrate processing system of claim 1, wherein:

said substrate processing system further comprises a pressure control system operatively coupled to maintain a selected pressure within said chamber, said pressure control system being controlled by said controller; and

wherein said computer readable program further comprises computer instructions that control said pressure control system to evacuate said deposition residue from said processing chamber during said first time period and said cleaning residue during said second time period.

5. The substrate processing system of claim 1, wherein said fluorine-containing compound comprises NF₃.

6. The substrate processing system of claim 1, wherein said second cleaning process gas comprises N₂.

7. The substrate processing system of claim 1, wherein:

said substrate processing system further comprises a pressure control system operatively coupled to maintain a selected pressure within said chamber, said pressure control system being controlled by said controller, and

wherein said computer readable program further comprises computer instructions that control said pressure control system to evacuate said deposition residue from said processing chamber during said first time period and said cleaning residue during said second time period.

8. The substrate processing system of claim 1, wherein said first cleaning process gas comprises a mixture of between about 8% and 13% ozone, by weight, in oxygen.

9. The substrate processing system of claim 1 wherein said first cleaning process gas comprises a mixture of oxygen and ozone, wherein the ratio of oxygen to ozone in said mixture is between about 12.5:

1 and 7.7;

1.

10. The substrate processing system of claim 1 wherein:

said computer instructions that control said plasma generation system apply RF power at a level of between 0.99-3.95 W/cm² when generating said plasma from said first cleaning process and apply RF power at a level of between about 0.79-3.95 W/cm² when generating said plasma from said second cleaning process gas.

11. A substrate processing system comprising:

a housing defining a chamber;

a gas distribution system adapted to introduce one or more gases into said chamber;

a plasma generation system operatively coupled to form a plasma within said chamber;

a controller for controlling said gas distribution system and said plasma generation system; and

a memory coupled to said controller comprising a computer readable medium having a computer readable program embodied therein for directing operation of said substrate processing system, said computer readable program comprising;

computer instructions that control said gas distribution system to flow a first cleaning process gas into said chamber, said first cleaning process gas comprising C₂ F₆ and ozone;

computer instructions that control said plasma generation system to form a plasma from said first cleaning process gas by applying said RF power at a first RF power density of between about 1.38 W/cm² for a first time period and then reduce said RF power density to between about 0.79 W/cm² and 1.19 W/cm² during a subsequent, second time period.

12. A substrate processing system comprising:

a housing defining a chamber;

a gas distribution system adapted to introduce one or more gases into said chamber;

a plasma generation system operatively coupled to form a plasma within said chamber;

a controller for controlling said gas distribution system and said plasma generation system; and

a memory coupled to said controller comprising a computer readable medium having a computer readable program embodied therein for directing operation of said substrate processing system, said computer readable program comprising;

computer instructions that control said gas distribution system to flow a cleaning process gas into said chamber, said cleaning process gas comprising a fluorine-containing compound;

computer instructions that control said plasma generation system to form a plasma from said first cleaning process gas by applying said RF power at a first RF power density of between about 1.38 W/cm² and 3.95 W/cm² for a first time period and then reduce said RF power density to between about 0.79 W/cm² and 1.19 W/cm² during a subsequent, second time period.

13. The substrate processing system of claim 12 wherein said computer program further includes computer instructions that control said gas distribution system to alter the composition of said cleaning process gas after said first time period by discontinuing a flow of said fluorine-containing source and commencing a flow of different fluorine-containing compound.

14. The substrate processing system of claim 13 wherein fluorine-containing compound comprises C₂ F₆.

15. The substrate processing system of claim 12 wherein said cleaning process gas further comprises ozone and said computer program further includes computer instructions that control said gas distribution system to alter the composition of said cleaning process gas after said first time period by discontinuing the flow of said ozone.