Plasma enhanced chemical processing reactor and method

• US 5,792,272 A
• Filed: 08/12/1997
• Issued: 08/11/1998
• Est. Priority Date: 07/10/1995
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Watkins Johnson Co. (Qorvo, Inc.)
• Inventors: Matthiesen, Richard H., van Os, Ron, Fenske, Dennis C., Durbin, William J., Ross, Eric D.
• Primary Examiner(s): Breneman, R. Bruce
• Assistant Examiner(s): LUND, JEFFRIE ROBERT
• Application Number:
  US08/909,580
• Time in Patent Office: 364 Days
• Field of Search: 156/345, 315/111.21, 315/111.51, 118/723 I, 118/723 IR, 118/729, 204/298.07, 204/298.15, 204/298.25, 204/298.33, 204/298.35
• US Class Current: 118/723.00R
• CPC Class Codes: C23C 16/4405 Cleaning of reactor or parts inside the reactor by using reactive gases
• CPC Class Codes: C23C 16/455 characterised by the method used for introducing gases into reaction chamber or for modifying gas flows in reaction chamber
• CPC Class Codes: C23C 16/507 using external electrodes, e.g. in tunnel type reactors
• CPC Class Codes: H01J 2237/3321 CVD [Chemical Vapor Deposition]
• CPC Class Codes: H01J 2237/3322 Problems associated with coating
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32862 In situ cleaning of vessels and/or internal parts

Abstract

A plasma enhanced chemical processing reactor and method. The reactor includes a plasma chamber including a first gas injection manifold and a source of electromagnetic energy. The plasma chamber is in communication with a process chamber which includes a wafer support and a second gas manifold. The plasma generated in the plasma chamber extends into the process chamber and interacts with the reactive gases to deposit a layer of material on the wafer. The reactor also includes a vacuum system for exhausting the reactor. The method includes the steps of generating a plasma within the plasma chamber, introducing at least one gaseous chemical into the process chamber proximate to the wafer support and applying r.f. gradient to induce diffusion of the plasma to the area proximate the wafer support.

Claims

1. A plasma chemical processing reactor, comprising:

a plasma chamber;

a first gas injection manifold communicating with said plasma chamber for receiving at least one first gas;

a source of electromagnetic energy for exciting said at least one first gas to form a plasma;

a process chamber communicating with the plasma chamber whereby the plasma extends into said process chamber;

a wafer support for supporting a wafer in coupled relationship to said plasma, said wafer support being suspended in said process chamber;

a continuous annular gas manifold, disposed in said process chamber above said wafer support mounted along the periphery of said process chamber for directing reactive gases towards said wafer support in such proximity that the density of the reactive gases is substantially uniform at the surface of said wafer, whereby the reactive gases interact with the plasma to process the surface of a wafer supported on said wafer support; and

a vacuum system, with an opening disposed directly beneath said wafer support and positioned substantially axially aligned with said process chamber to promote substantially equal effective pumping speed at the wafer, whereby to provide substantially axial flow of the gases around the surface of the wafer and for removing gases from the bottom of said process chamber in a substantially symmetrical manner.

2. The reactor of claim 1 wherein said source of electromagnetic energy is an inductively coupled plasma source.

3. The reactor of claim 1 wherein said source of electromagnetic energy comprises a helical resonator and a capacitive shield disposed within said helical resonator.

4. The reactor of claim 1 wherein said wafer support is attached to at least one surface of said process chamber, such that said wafer support is suspended within said process chamber.

5. The reactor of claim 1 wherein said vacuum system comprises a turbo pump.

6. The reactor of claim 5 wherein said vacuum system further comprises a vacuum isolation valve disposed between said process chamber and said pump for isolating said process chamber from said pump.

7. The reactor of claim 1 wherein said second gas manifold includes a plurality of spaced nozzles for distributing gases proximate to said wafer.

8. The reactor of claim 1 wherein said wafer support comprises a support body having a support surface for retaining said wafer;

a voltage source coupled to said support body for electrostatically coupling said wafer to said support surface;

a cooling system having a plurality of gas distribution grooves formed in said support surface and configured for uniformly distributing a gaseous substance between said wafer and said support surface;

at least one member having two ends, one of said ends attached to said support body and the other said end attached to a surface of said process chamber.

9. The reactor of claim 8 wherein said at least one member is attached to a vertical surface of said process chamber such that said support body is suspended within said process chamber.

10. The reactor of claim 9 wherein said at least one member is hollow and contains therein at least one conduit for passing cooling medium to said support body, and at least one conduit for coupling dc energy to said wafer support.

11. The reactor of claim 8 wherein said at least one member is hollow and contains therein at least one conduit for passing cooling medium to said support body, and at least one conduit for coupling dc energy to said wafer support.

12. The reactor of claim 11 wherein said at least one member further comprises at least one conduit for coupling r.f. energy to said wafer support.

13. The reactor of claim 1 wherein said wafer support is attached to a carriage assembly, and said carriage assembly is attached to said process chamber, such that said wafer support may be removed from said process chamber.

14. The reactor of claim 1 wherein said first gas manifold comprises at least one plenum formed therein for receiving at least one gaseous chemical;

and

a plurality of holes communicating with each of said at least one plenum and said holes disposed along said plenum, for distributing said at least one gaseous chemical to said plasma chamber.

15. A plasma CVD system for depositing a void free layer of material on the surface of a wafer, comprising:

a plasma chamber having a source of electromagnetic energy, said source having a helical resonator and a capacitive shield disposed within said helical resonator for exciting a gas to form a plasma having an ion density of equal to or greater than 10¹¹ ions/cm³ ;

a process chamber communicating with said plasma chamber for receiving reactive gases and whereby the plasma extends into said process chamber;

a support, in said processing chamber, for supporting a wafer for interaction with the reactive gases and the plasma extending into the process chamber to form a layer of material on the surface of said wafer;

a continuous annular gas manifold disposed in said process chamber above said support mounted along the periphery of said process chamber for directing reactive gases towards said support in such proximity that the density of the reactive gases is substantially uniform at the surface of said wafer, whereby the reactive gases interact with the plasma to process the surface of said wafer supported on said support; and

a vacuum system, with an opening disposed directly beneath said support to promote substantially equal effective pumping speed at the wafer, and for evacuating said process chamber,

wherein said layer fills gaps on said surface having a width of less than approximately 0.5 microns and a depth greater than or equal to two times the width without the presence of voids.

16. The reactor of claim 15 wherein said support is attached to at least one surface of said process chamber, such that said support is suspended within said process chamber.

17. The reactor of claim 15 wherein said support comprises a support body having a support surface for retaining said wafer;

a voltage source coupled to said support body for electrostatically coupling said wafer to said support surface;

a cooling system having a plurality of gas distributions grooves formed in said support surface and configured for uniformly distributing a gaseous substance between said wafer and said support surface;

at least one member having two ends, one of said ends attached to said support body and the other said end attached to a surface of said process chamber.

18. The reactor of claim 17 wherein said at least one member is hollow and contains therein at least one conduit for passing cooling medium to said support body, and at least one conduit for coupling dc energy to said support.

19. The reactor of claim 18 wherein said at least one member further comprises at least one conduit for coupling r.f. energy to said support.

20. A plasma CVD system, comprising:

a plasma chamber;

a first gas injection -manifold communicating with said plasma chamber;

a source of electromagnetic energy;

a process chamber communicating with the plasma chamber;

a wafer support for supporting a wafer, said wafer support being substantially axially aligned with said process chamber;

a continuous annular gas manifold for receiving a first gas and a plurality of reactive gases wherein said first gas is excited by said source of electromagnetic energy to form a plasma, said continuous annular gas manifold being substantially axially aligned with said process chamber above said wafer support mounted along the periphery of said process chamber and where reactive gases are directed towards said wafer support in such proximity that the density of the reactive gases is substantially uniform at the surface of said wafer, whereby the reactive gases interact with the plasma and deposit a material on the wafer; and

a vacuum system substantially axially aligned with said process chamber with an opening disposed directly beneath said wafer support to promote substantially equal effective pumping speed at the wafer, and for providing substantially axial flow of the gases around the surface of the wafer and for removing gases from said process chamber in a substantially symmetrical manner.

21. The reactor of claim 20 wherein said wafer support is attached to at least one surface of said process chamber, such that said wafer support is suspended within said process chamber.

22. The reactor of claim 20 wherein said first gas manifold comprises a plurality of channels formed therein for discretely receiving at least one gaseous chemical;

and a plurality of holes communicating with each of said channels, for discretely distributing said at least one gaseous chemical to said plasma chamber.

23. The reactor of claim 20 wherein said vacuum system comprises a turbo pump.

24. The reactor of claim 23, wherein said vacuum system further comprises a vacuum isolation valve disposed between said process chamber and said pump for isolating said process chamber from said pump.

25. The reactor of claim 20 wherein said second gas manifold includes a plurality of spaced nozzles for distributing gases proximate to said wafer.

26. The reactor of claim 20 wherein said wafer support comprises a support body having a support surface for retaining said wafer;

a voltage source coupled to said support body for electrostatically coupling said wafer to said support surface;

a cooling system having a plurality of gas distribution grooves formed in said support surface and configured for uniformly distributing a gaseous substance between said wafer and said support surface;

at least one member having two ends, one of said ends attached to said support body and the other said end attached to a surface of said process chamber.

27. The reactor of claim 26 wherein said at least one member is hollow and contains therein at least one conduit for passing cooling medium to said support body, and at least one conduit for coupling dc energy to said wafer support.

28. The reactor of claim 27 wherein said at least one member further comprises at least one conduit for coupling r.f. energy to said wafer support.

29. The reactor of claim 20 wherein said wafer support is attached to a carriage assembly, and said carriage assembly is attached to said process chamber, such that said wafer support may be removed from said process chamber.

30. A plasma chemical processing reactor, comprising:

a cylindrical plasma chamber;

a first gas injection manifold communicating with said plasma chamber;

a source of electromagnetic energy having a helical resonator and a capacitive shield disposed within said helical resonator, for exciting at least a first gas to form a plasma having an ion density of equal to or greater than 10¹¹ ions/cm³ ;

a cylindrical process chamber communicating with the plasma chamber;

a wafer support for supporting a wafer in coupled relationship to said plasma, said wafer support being disposed on axis within said process chamber and attached to at least one vertical surface of said process chamber such that said wafer support is suspended within said process chamber;

a continuous annular gas manifold for receiving the at least a first gas and a plurality of reactive gases, disposed on axis within said process chamber, above said wafer support and mounted along the periphery of said process chamber for directing reactive gases towards said wafer support in such proximity that the gas density of the reactive gases is substantially uniform at the surface of said wafer, whereby the reactive gases interact with the plasma to deposit a material on the wafer; and

a vacuum system communicating with said process chamber, with an opening disposed directly beneath said wafer support to promote substantially equal effective pumping speed at the wafer, and being substantially aligned on axis with said process chamber, for providing substantially axial flow of the gases around said wafer and for removing gases from said process chamber in a substantially symmetrical manner.

31. The reactor of claim 30 wherein said vacuum system comprises a turbo pump.

32. The reactor of claim 30 wherein said vacuum system further comprises a vacuum isolation valve disposed between said process chamber and said pump for isolating said process chamber from said pump.

33. The reactor of claim 30 wherein said second gas manifold includes a plurality of spaced nozzles for distributing gases proximate to said wafer.

34. The reactor of claim 30 wherein said wafer support comprises a support body having a support surface for retaining said wafer;

a voltage source coupled to said support body for electrostatically coupling said wafer to said support surface;

a cooling system having a plurality of gas distribution grooves formed in said support surface and configured for uniformly distributing a gaseous substance between said wafer and said support surface;

at least one member having two ends, one of said ends attached to said support body and the other said end attached to a surface of said process chamber.

35. The reactor of claim 34 wherein said at least one member is hollow and contains therein at least one conduit for passing cooling medium to said support body, and at least one conduit for coupling dc energy to said wafer support.

36. The reactor of claim 35 wherein said at least one member further comprises at least one conduit for coupling r.f. energy to said wafer support.

37. The reactor of claim 34 wherein said at least one member further comprises at least one conduit for coupling r.f. energy to said wafer support.

38. The reactor of claim 30 wherein said wafer support is attached to a carriage assembly, and said carriage assembly is attached to said process chamber, such that said wafer support may be removed from said process chamber.

39. The reactor of claim 30 wherein said first gas manifold comprises at least one plenum formed therein for discretely receiving at least one gaseous chemical;

and

a plurality of holes communicating with each of said at least one plenum and said holes disposed along said plenum, for discretely distributing said at least one gaseous chemical to said plasma chamber.