Method and system for rotating a semiconductor wafer in processing chambers

• US 6,770,146 B2
• Filed: 02/02/2001
• Issued: 08/03/2004
• Est. Priority Date: 02/02/2001
• Status: Expired due to Term

• Current Assignee: Mattson Technology, Inc. (Beijing Economic & Technology Development Area), BeiJing E-Town Semiconductor Technology Co., Ltd.
• Original Assignee: Mattson Technology, Inc. (Beijing Economic & Technology Development Area)
• Inventors: Koren, Zion, Taoka, James Tsuneo, Gibson, Shawn, McFarland, Craig, Tomas Cardema, Rudy Santo, Ma, Yorkman, Wride, Lois
• Primary Examiner(s): Mills, Gregory
• Assistant Examiner(s): KACKAR, RAM N
• Application Number:
  US09/776,241
• Publication Number:
  US 20020104619A1
• Time in Patent Office: 1,278 Days
• Field of Search: 118/730, 118/725, 118/500, 118/50.1, 156/345.51, 156/345.52, 156/345.55, 310/90.5, 310/237
• US Class Current: 118/730
• CPC Class Codes: B05C 11/08 Spreading liquid or other fluent material by manipulating the work, e.g. tilting
• CPC Class Codes: C23C 16/4584 the substrate being rotated
• CPC Class Codes: H01L 21/67115 mainly by radiation
• CPC Class Codes: H01L 21/68792 characterised by the construction of the shaft

Abstract

The present invention is generally directed to a system and process for rotating semiconductor wafers in thermal processing chambers, such as rapid thermal processing chambers and chemical vapor deposition chambers. In accordance with the present invention, a semiconductor wafer is supported on a substrate holder which, in turn, is supported on a rotor. During processing, the rotor is magnetically levitated and magnetically rotated by suspension actuators and rotation actuators positioned outside of the chamber.

Claims

1. A system for processing semiconductor wafers comprising:

a thermal processing chamber adapted to contain semiconductor wafers;

a heating device for heating semiconductor wafers contained within said chamber;

a rotor positioned within said thermal processing chamber having a top and bottom, said rotor being configured to support a semiconductor wafer, said rotor having a circular shape and being comprised of a material capable of being influenced by a magnetic force; and

at least one rotation actuator having a first rotation surface spaced from a second opposing rotation surface, the first rotation surface being positioned above the rotor and facing the top of the rotor, the second rotation surface being positioned below the rotor and facing the bottom of the rotor, said rotor being positioned in between said first and second rotation surfaces, said rotation actuator being configured to generate a magnetic field that causes said rotor to rotate without contacting said rotor.

2. A system as defined in claim 1, wherein said rotation actuator is positioned outside of said thermal processing chamber.

3. A system as defined in claim 1, wherein said rotation actuator comprises a C-shaped magnetic element having a pair of opposing poles that define said first and second rotation surfaces, said C-shaped magnetic element being placed in operative association with an electric coil that generates said magnetic field when an electric current is fed through said coil.

4. A system as defined in claim 1, wherein said rotor includes spaced apart radial teeth, said teeth being positioned in between said first and second opposing rotation surfaces.

5. A system as defined in claim 4, wherein said rotation actuator is configured to generate a variable magnetic field which acts upon said radial teeth to rotate said rotor.

6. A system as defined in claim 1, wherein said system includes at least three rotation actuators.

7. A system as defined in claim 1, wherein said system includes at least six rotation actuators.

8. A system as defined in claim 1, further comprising at least one suspension actuator positioned above said rotor, said suspension actuator being configured to generate a magnetic field and levitate said rotor during rotation.

9. A system as defined in claim 8, wherein said system includes at least three suspension actuators spaced around said rotor.

10. A system as defined in claim 8, wherein said suspension actuator includes a first suspension surface and a second suspension surface that face said rotor, said surfaces being capable of being magnetized for levitating said rotor.

11. A system as defined in claim 10, wherein said rotor includes first and second annular raised portions, said first and second annular raised portions being positioned below said first and second suspension surfaces respectively.

12. A system as defined in claim 8, further comprising a position senor and speed sensor located adjacent to said rotor, said position senor for monitoring the vertical position of said rotor, said speed sensor for monitoring the speed of said rotor.

13. A system as defined in claim 1, wherein said heating device comprises a plurality of light energy sources positioned outside said chamber.

14. A system as defined in claim 1, further comprising:

a temperature sensing device for sensing the temperature of a semiconductor wafer contained in said thermal processing chamber; and

a controller in communication with said temperature sensing device, said controller receiving temperature information from said temperature sensing device and, based on said information, adjusting said heating device for controlling the temperature of said semiconductor wafer within preset limits.

15. A system for processing semiconductor wafers comprising:

a thermal processing chamber adapted to contain semiconductor wafers;

a heating device for heating semiconductor wafers contained within said chamber;

a rotor positioned within said thermal processing chamber, said rotor being configured to support a semiconductor wafer, said rotor having a circular shape and being comprised of a material capable of being influenced by a magnetic force;

at least one suspension actuator positioned above said rotor, said suspension actuator including a first suspension surface and a second suspension surface that each face said rotor, said rotor including first and second annular raised portions, said first and second raised portions being positioned below said first and second suspension surfaces respectively, said suspension actuator being configured to generate a magnetic field through said first and second suspension surfaces for levitating said rotor without contacting said rotor; and

a rotation device that generates a magnetic field for rotating said rotor when levitated.

16. A system as defined in claim 15, wherein said system includes at least three suspension actuators spaced around said rotor.

17. A system as defined in claim 15, wherein said heating device comprises a plurality of light energy sources.

18. A system as defined in claim 15, further comprising a position sensor and a speed sensor located adjacent to said rotor, said position senor for monitoring the vertical position of said rotor, said speed sensor for monitoring the speed of said rotor.

19. A system as defined in claim 15, wherein said suspension actuator comprises a U-shaped magnetic element having a pair of opposing ends that define the first and second suspension surfaces, said U-shaped magnetic element being placed in operative association with an electric coil that generates a magnetic field when an electric current is fed through said coil.

20. A system as defined in claim 15, wherein said system includes at least two suspension actuators spaced around said rotor, and wherein said system further comprises:

a position sensor for monitoring the vertical position of said rotor in relation to a horizontal plane; and

a controller in communication with said position sensor and with said suspension actuators, said controller being configured to receive information from said position sensor regarding the position of said rotor and, based on said information, to independently adjust each of said suspension actuators for levitating said rotor a determined distance and for maintaining said rotor parallel to said horizontal plane.

21. A system as defined in claim 20, wherein said controller is further configured to control said rotation device for controlling the rotation of said rotor.

22. A system as defined in claim 15, wherein said rotation device includes at least one rotation actuator having a first rotation surface spaced from a second opposing rotation surface, said rotor being positioned in between said first and second rotation surfaces, said rotation actuator being configured to generate a magnetic field that causes such rotor to rotate without contacting said rotor.

23. A system for processing semiconductor wafers comprising:

a thermal processing chamber adapted to contain semiconductor wafers;

a heating device for heating semiconductor wafers contained within said chamber;

a rotor positioned within said thermal processing chamber, said rotor being configured to support a semiconductor wafer, said rotor having a circular shape and being comprised of a material capable of being influenced by a magnetic force, said rotor including spaced apart radial teeth; and

at least one rotation actuator positioned adjacent to said rotor, the rotation actuator including a first rotation surface spaced from a second opposing rotation surface, the spaced apart radial teeth of the rotor being rotatably positioned in between the first and second rotation surfaces, said rotation actuator being configured to generate a pulsating magnetic field which acts upon said radial teeth to rotate said rotor.

24. A system as defined in claim 23, wherein said rotation actuator includes a magnetic element having a pair of opposing ends that define the first rotation surface and the second opposing rotation surface, said magnetic element being in operative association with a magnetic coil that generates said magnetic field when an electric current is fed through said coil.

25. A system as defined in claim 23, wherein said system includes at least three rotation actuators.

26. A system as defined in claim 23, further comprising at least one suspension actuator positioned above said rotor, said suspension actuator being configured to generate a magnetic field and levitate said rotor during rotation.

27. A system as defined in claim 26, wherein said system includes at least three suspension actuators spaced around said rotor.

28. A system as defined in claim 26, wherein said suspension actuator includes a first suspension surface and a second suspension surface that face said rotor, said surfaces capable of being magnetized for levitating said rotor.

29. A system as defined in claim 28, wherein said rotor includes first and second annular raised portions, said first and second suspension surfaces respectively.

30. A system as defined in claim 26, wherein said system includes at least two suspension actuators spaced around said rotor, and wherein said system further comprises:

a position sensor for monitoring the vertical position of said rotor in relation to a horizontal plane; and

a controller in communication with said position senor and with said suspension actuators, said controller being configured to receive information from said position sensor regarding the position of said rotor and, based on said information, to independently adjust each of said suspension actuators for levitating said rotor a determined distance and for maintaining said rotor parallel to said horizontal plane.

31. A system as defined in claim 26, wherein said rotation actuator is positioned outside of said thermal processing chamber.

32. A system for processing semiconductor wafers comprising:

a thermal processing chamber adapted to contain semiconductor wafers;

a heating device for heating semiconductor wafers contained in said chamber;

a rotor positioned within said thermal processing chamber, said rotor being configured to support a semiconductor wafer supporting said substrate holder, said rotor having a circular shape and being comprised of a material capable of being influenced by a magnetic force;

at least one rotation actuator positioned adjacent to said rotor outside of said thermal processing chamber, said rotation actuator comprising a rotation element placed in operative association with a magnetic coil that generates a magnetic field when an electric current is fed through said coil, said rotor including spaced apart radial teeth and wherein said rotation actuator is configured to generate a pulsating magnetic field which acts upon said radial teeth to rotate said rotor;

at least one suspension actuator positioned above said rotor outside of said thermal processing chamber, said suspension actuator being configured to generate a magnetic field and levitate said rotor during rotation; and

a controller in communication with said rotation actuator and said suspension actuator, said controller being configured to control said rotation actuator and said suspension actuator for levitating and rotating said rotor at selected times.

33. A system as defined in claim 32, wherein said rotation actuator defines a first rotation surface and a second rotation surface, said radial teeth of said rotor being spaced in between said first and second rotation surfaces.

34. A system as defined in claim 32, wherein said system includes at least three suspension actuators positioned above said rotor.

35. A system as defined in claim 32, wherein said rotor has a conically-shaped surface and wherein said suspension actuator is positioned adjacent to said surface for levitating said rotor and for maintaining said rotor at a particular radial and also axial position.

36. A system as defined in claim 32, wherein said suspension actuator includes a first suspension surface and a second suspension surface that face said rotor, said surfaces capable of being magnetized for levitating said rotor.

37. A system as defined in claim 36, wherein said rotor includes first and second annular raised portions, said first and second annular raised portions being positioned below said first and second suspension surfaces respectively.

38. A system as defined in claim 32, wherein said system includes at least two suspension actuators spaced around said rotor and wherein said system further comprises a position sensor for monitoring the vertical position of said rotor in relation to a horizontal plane, said position sensor being in communication with said controller and wherein said controller is configured to receive information from said position sensor and, based on said information, to independently control said suspension actuators for levitating said rotor a selected distance and for maintaining said rotor parallel to said horizontal plane.