Method for improved remote microwave plasma source for use with substrate processing system

• US 6,271,148 B1
• Filed: 10/13/1999
• Issued: 08/07/2001
• Est. Priority Date: 04/23/1997
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Rose, Ronald L., Pham, Quyen, Augason, Calvin R., Kao, Chien-Teh, Yudovsky, Joseph, Tsai, Kenneth
• Primary Examiner(s): Utech, Benjamin L.
• Assistant Examiner(s): ALEJANDRO MULERO, LUZ L
• Application Number:
  US09/416,861
• Time in Patent Office: 664 Days
• Field of Search: 438/727, 438/726, 438/728, 216/69, 216/70, 118/723.ME, 427/569, 427/575
• US Class Current: 438/727
• CPC Class Codes: C23C 16/4405 Cleaning of reactor or parts inside the reactor by using reactive gases
• CPC Class Codes: C23C 16/452 by activating reactive gas streams before their introduction into the reaction chamber, e.g. by ionisation or addition of reactive species
• CPC Class Codes: C23C 16/52 Controlling or regulating the coating process C23C16/45557, C23C16/279 take precedence
• CPC Class Codes: H01J 37/32192 Microwave generated discharge H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream
• CPC Class Codes: H01J 37/32862 In situ cleaning of vessels and/or internal parts
• CPC Class Codes: H01L 21/67028 for cleaning followed by drying, rinsing, stripping, blasting or the like

Abstract

An apparatus and methods for an upgraded CVD system providing a remote plasma for efficiently cleaning a chamber, according to a specific embodiment. Etching or depositing a layer onto a substrate also may be achieved using the upgraded CVD system of the present invention. In a specific embodiment, the present invention provides apparatus for an easily removable, conveniently handled, and relatively inexpensive, robust microwave plasma source as a retrofit for or a removable addition to existing CVD apparatus. The present invention provides an improved CVD apparatus or retrofit of existing CVD apparatus capable of producing a remote plasma for efficiently cleaning the chamber.

Claims

1. A method for plasma processing using an apparatus having a conductive plasma applicator, the method comprising:

introducing said one or more reactive gases at a first rate to a gas inlet of the plasma applicator during a first time period at a first flow rate;

directing microwaves into an internal volume of the applicator during said first time period to ignite a plasma in said applicator; and

permitting radicals generated by the plasma to exit from the applicator through an outlet while containing the microwaves within the applicator.

2. The method of claim 1, further comprising maintaining a pressure within the applicator at about 1-20 torr within the applicator during said first time period.

3. The method of claim 1 wherein said one or more reactive gases is selected from the group consisting of NF₃, dilute F₂, CF₄, C₂F₆, C₃F₈, SF₆, and ClF₃.

4. The method of claim 1 wherein said microwaves form standing waves in said internal volume.

5. The method of claim 1 further comprising:

introducing radicals from said plasma into a substrate processing chamber coupled to the applicator to process a substrate.

6. The method of claim 1, further comprising:

maintaining the applicator at a selected temperature.

7. The method of claim 6 wherein said selected temperature is between about 20°

C. and about 25°

C.

8. The method of claim 1, wherein the applicator has a rectangular cross section having a width and a height.

9. The method of claim 8, wherein the width and height are chosen such that the microwaves resonate in a TE_10n mode, wherein n is an integer.

10. The method of claim 1, wherein the applicator has a cylindrical shape characterized by a radius and a length.

11. The method of claim 10, wherein the radius and length are chosen such that the microwaves resonate in a TE₁₁mode, wherein n is an integer.

12. The method of claim 1 wherein the microwaves are directed into the internal volume of the applicator at a power level ranging from about 150-500 W.

13. The method of claim 1 wherein the microwaves are contained within the applicator by providing a microwave arrestor in the outlet of the applicator.

14. The method of claim 13 wherein the microwave arrestor extends coextensive with a cross-sectional area of the outlet.

15. A method for plasma processing in a processing chamber, comprising:

during a first time period introducing one or more reactive gases at a first flow rate to a gas inlet of a conductive plasma applicator coupled to the processing chamber;

maintaining a pressure of about 1-20 torr within the applicator during said first time period;

directing microwaves into an internal volume of the applicator during said first time period at a power level ranging from about 150-500 W to ignite a plasma in said applicator; and

introducing radicals from the plasma through an outlet from the applicator into the processing chamber while containing the microwaves within the applicator.

16. The method of claim 15, wherein said one or more reactive gases includes a fluorine-containing gas or a chlorine-containing gas.

17. The method of claim 15, wherein said one or more reactive gases is selected from the group consisting of NF₃, dilute F₂, CF₄, C₂F₆, C₃F₈, SF₆, and ClF₃.

18. The method of claim 15 wherein the radicals are introduced from the plasma into the processing chamber to clean the processing chamber.

19. The method of claim 18, wherein the processing chamber is a CVD chamber.

20. The method of claims 19 wherein the radicals remove residues from an interior of said CVD chamber.

21. The method of claim 20 wherein said residues include a material from the group of silicides, oxides, nitrides and metal-containing residues.

22. The method of claim 21, wherein said residues include tungsten silicide.

23. The method of claim 15, wherein the microwaves are contained within the applicator by providing a microwave arrestor in the outlet of the applicator.

24. The method of claim 23 wherein the microwave arrestor extends coextensive with a cross-sectional area of the outlet.

25. The method of claim 15 wherein the radicals are introduced from the plasma into the processing chamber to process a substrate in the processing chamber.

26. The method of claim 25 wherein processing the substrate includes an etching process or a deposition process.