Apparatus for improved remote microwave plasma source for use with substrate processing systems

• US 6,026,762 A
• Filed: 04/23/1997
• Issued: 02/22/2000
• Est. Priority Date: 04/23/1997
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Kao, Chien-Teh, Yudovsky, Joseph, Tsai, Kenneth, Rose, Ronald L., Pham, Quyen, Augason, Calvin R.
• Primary Examiner(s): Dang, Thi
• Assistant Examiner(s): ALEJANDRO MULERO, LUZ L
• Application Number:
  US08/839,111
• Time in Patent Office: 1,035 Days
• Field of Search: 118/223 ME, 118/723 MW, 118/723 MR, 118/723 MA, 156/345, 333/99 PL, 333/252, 315/111.21, 204/298.38
• US Class Current: 118/723.0ME
• 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 remote microwave plasma apparatus comprising:

a body defining a resonant cavity and having a fluid inlet and a fluid outlet;

a source of microwave energy in electrical communication with said cavity; and

a microwave arrestor positioned within said fluid outlet, extending coextensive with a cross-sectional area of said fluid outlet.

2. The apparatus of claim 1 wherein said body has heat exchange passages.

3. The apparatus of claim 2 wherein said resonant cavity has a cylindrical shape.

4. The apparatus of claim 3 wherein said resonant cavity has a length ranging from about 2-4 inches and a radius ranging from about 1.5-5 inches.

5. The apparatus of claim 2 wherein said fluid outlet is disposed in said second end wall.

6. The apparatus of claim 5 wherein said fluid inlet is disposed in said second end wall.

7. The apparatus of claim 1 wherein said resonant cavity has a rectangular shape.

8. The apparatus of claim 1 wherein said fluid inlet and said fluid outlet have a substantially circular cross-section.

9. The apparatus of claim 8 wherein said body includes first and second spaced-apart end walls, with a microwave-transparent plate disposed in said first end wall.

10. The apparatus of claim 9 wherein said microwave-transparent plate is comprised of Al₂ O₃.

11. The apparatus of claim 8 wherein said body further includes a conductive wall extending between said first and second end walls.

12. The apparatus of claim 11 wherein said fluid inlet and said fluid outlet are disposed in said conductive wall.

13. The apparatus of claim 11 wherein said fluid inlet and said fluid outlet are disposed in said second end wall.

14. The apparatus of claim 1 wherein said fluid inlet is in fluid communication with a supply of reactive gas, with said reactive gas being selected from a group consisting of NF₃, dilute F₂, CF₄, C₂ F₆, C₃ F₈, SF₆, and ClF₃.

15. The apparatus recited in claim 1 including an additional microwave arrestor positioned within said fluid inlet and extending coextensive with a cross-sectional area thereof.

16. The apparatus recited in claim 15 wherein said body has a first end wall and a second end wall, spaced-apart from said first end wall, with said first end wall including a microwave-transparent portion, with side walls extending between said first and second end walls.

17. The apparatus recited in claim 16 wherein said second end wall and said side walls are formed from electrically conductive material.

18. The apparatus recited in claim 14 wherein said resonant cavity has a rectangular cross-section.

19. The apparatus recited in claim 17 wherein said resonant cavity has a circular cross-section.

20. The apparatus as recited in claim 17 wherein said fluid inlet is disposed opposite to said fluid outlet.

21. The apparatus as recited in claim 17 wherein said fluid inlet is coplanar with said fluid outlet.

22. An improved substrate processing system comprising:

a processing chamber;

a gas delivery system configured to deliver a reactive gas to said processing chamber;

a heating system including a pedestal in said processing chamber, said pedestal for holding a substrate, said pedestal being heated to a selected temperature;

a vacuum system configured to set and maintain a selected pressure within said processing chamber;

a remote microwave plasma system coupled to said processing chamber, said remote microwave plasma system comprising,

a conductive plasma applicator defining an internal volume, said applicator including,

a first end wall, said first end wall including a microwave-transparent plate,

a conductive second end wall opposite said first end wall,

a gas inlet for receiving a reactive gas into said internal volume of said applicator, and

an outlet, said gas inlet and said outlet equipped with microwave arrestors.

23. The apparatus of claim 22 further comprising:

a controller configured to control said gas delivery system, said heating system, said remote microwave plasma system, and said vacuum 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 apparatus.

24. The apparatus of claim 23 wherein said third subset of computer instructions controls said remote microwave plasma system to direct said microwave energy at a power level ranging from about 150-500 W to ignite said plasma in said applicator.

25. The improved apparatus of claim 23 wherein said computer-readable program includes:

a first set of computer instructions for introducing said radicals from said plasma into said processing chamber from said outlet of said plasma applicator, said first set of computer instructions including;

a first subset of computer instructions for controlling said gas delivery system to introduce said reactive gas at a first rate to said gas inlet during a first time period at a first flow rate;

a second subset of computer instructions for controlling said vacuum system to maintain a pressure of about 1-20 torr within said applicator during said first time period; and

a third subset of computer instructions for controlling said remote microwave plasma system to direct said microwaves into said internal volume of said applicator during said first time period.

26. The apparatus of claim 22 wherein said gas inlet is in fluid communication with said gas delivery system, with said reactive gas is selected from a group consisting of NF₃, dilute F₂, CF₄, C₂ F₆, C₃ F₈, SF₆, and ClF₃.

27. The apparatus of claim 22 wherein said conductive plasma applicator and said conductive second wall are comprised of metal.

28. The apparatus of claim 22 wherein said microwaves form standing waves in said internal volume.