Heating device containing a multi-lamp cone for heating semiconductor wafers

• US 6,210,484 B1
• Filed: 09/09/1998
• Issued: 04/03/2001
• Est. Priority Date: 09/09/1998
• Status: Expired due to Fees

• Current Assignee: STEAG RTP Systems, Inc. (KSBG Kommunale Beteiligungsgesellschaft GmbH & Company KG)
• Original Assignee: STEAG RTP Systems, Inc. (KSBG Kommunale Beteiligungsgesellschaft GmbH & Company KG)
• Inventors: Hathaway, Kevin
• Primary Examiner(s): Mills, Gregory
• Assistant Examiner(s): HASSANZADEH, PARVIZ
• Application Number:
  US09/150,280
• Time in Patent Office: 937 Days
• Field of Search: 118/724, 118/728, 118/715, 118/725, 156/345, 219/422, 219/410, 219/411, 219/413, 219/405, 392/416, 392/411, 392/418, 392/422, 392/425, 392/427, 392/428, 438/65, 438/66
• US Class Current: 118/724
• CPC Class Codes: H01L 21/67115 mainly by radiation

Abstract

An apparatus for heat treating semiconductor wafers is disclosed. The apparatus includes a heating device which contains an assembly of light energy sources for emitting light energy onto a wafer. In particular, the present invention is directed to a heating device that contains at least one heating cone. The heating cone of the present invention includes a circular reflector that can be conically-shaped. A plurality of light energy sources are contained within the reflector. The light energy sources can be vertically oriented or can be tilted slightly towards the central axis of the heating cone. In this arrangement, it has been discovered that the heating cone produces a uniform irradiance distribution over a wafer being heated.

Claims

1. An apparatus for heat treating semiconductor wafers comprising:

a thermal processing chamber adapted to contain a semiconductor wafer, said thermal processing chamber containing at least one sidewall, an upper wall, and a lower wall;

a heating device in communication with said thermal processing chamber for heating a semiconductor wafer contained in said chamber using electromagnetic energy, said heating device comprising at least one heating cone having an axis perpendicular to said semiconductor wafer, said heating cone including a plurality of light energy sources positioned within a conically-shaped reflector, said conically-shaped reflector gradually decreasing in diameter in a direction towards said semiconductor wafer; and

a window separating said heating device from said thermal processing chamber, said window being disposed on either said upper wall or said lower wall of said thermal processing chamber.

2. An apparatus as defined in claim 1, wherein said plurality of light energy sources are arranged in a circular configuration within said conically-shaped reflector.

3. An apparatus as defined in claim 1, wherein at least six light energy sources are contained within said conically-shaped reflector.

4. An apparatus as defined in claim 1, wherein at least certain of said light energy sources positioned within said conically-shaped reflector are tilted towards said axis of said heating cone.

5. An apparatus as defined in claim 4, wherein said light energy sources are tilted up to about 20 degrees with respect to said axis.

6. An apparatus as defined in claim 4, wherein said light energy sources are tilted from about 6 degrees to about 12 degrees with respect to said axis.

7. An apparatus as defined in claim 4, wherein certain of said light energy sources are tilted and certain of said light energy sources are vertically oriented with respect to said axis of said heating cone.

8. An apparatus as defined in claim 1, wherein said diameter of said conically-shaped reflector has a slope of up to 20 degrees with respect to said axis of said heating cone.

9. An apparatus as defined in claim 8, wherein said slope is from about 6 degrees to about 12 degrees with respect to said axis.

10. An apparatus as defined in claim 1, wherein said heating device further comprises concentric rings of light energy sources surrounding said heating cone.

11. An apparatus as defined in claim 10, wherein at least certain of said light energy sources positioned within said conically-shaped reflector are tilted towards said axis of said heating cone.

12. An apparatus as defined in claim 1, wherein said heating device includes at least two heating cones.

13. An apparatus as defined in claim 1, wherein said heating cone further comprises a reflective top enclosing said conically-shaped reflector.

14. An apparatus as defined in claim 13, wherein said reflective top is more light diffusive than said conically-shaped reflector.

15. An apparatus as defined in claim 13, wherein at least certain of said light energy sources positioned within said conically-shaped reflector are tilted towards said axis of said heating cone.

16. An apparatus as defined in claim 1, further comprising:

at least one temperature sensing device for sensing the temperature of said semiconductor wafer at least at one location; and

a controller in communication with said at least one temperature sensing device and at least certain of said light energy sources, said controller being configured to control the amount of electromagnetic energy being emitted by said light energy sources in response to temperature information received from said at least one temperature sensing device.

17. An apparatus as defined in claim 16, wherein said controller is configured to control the amount of electromagnetic energy being emitted by said light energy sources contained in said heating cone independent of other light energy sources included in said heating device.

18. An apparatus as defined in claim 1, further comprising a substrate holder for holding said semiconductor wafer, said substrate holder being configured to rotate said wafer.

19. An apparatus for heat treating semiconductor wafers comprising:

a thermal processing chamber, said thermal processing chamber containing at least one sidewall, an upper wall, and a lower wall;

a substrate holder contained in said thermal processing chamber for holding a semiconductor wafer, said substrate holder being configured to rotate said wafer;

a heating device in communication with said thermal processing chamber for heating a semiconductor wafer held on said substrate holder using electromagnetic energy, said heating device comprising at least one heating cone having an axis perpendicular to said semiconductor wafer, said heating cone including a plurality of light energy sources positioned within a circular reflector, wherein at least certain of said light energy sources positioned within said circular reflector are tilted towards said axis of said heating cone, said light energy sources being tilted in an amount up to about 20 degrees with respect to said axis; and

a window separating said heating device from said thermal processing chamber, said window being disposed on either said upper wall or said lower wall of said thermal processing chamber.

20. An apparatus as described in claim 19, wherein some of said light energy sources are tilted and some of said light energy sources are vertically oriented with respect to said axis.

21. An apparatus as defined in claim 19, wherein said circular reflector is conically-shaped such that said reflector gradually increases or decreases in diameter in a direction towards said semiconductor wafer.

22. An apparatus as defined in claim 21, wherein said heating cone further includes a reflective top enclosing said circular reflector.

23. An apparatus as defined in claim 22, wherein said reflective top is dome-shaped.

24. An apparatus as defined in claim 22, wherein said reflective top is more light diffusive than said circular reflector.

25. An apparatus as defined in claim 24, wherein said reflective top is at least 75% light diffusive and said circular reflector is less than 10% light diffusive.

26. An apparatus as defined in claim 22, wherein said reflective top is cone-shaped.

27. An apparatus as defined in claim 19, wherein said circular reflector is conically-shaped such that said reflector gradually increases in diameter in a direction towards the semiconductor wafer.

28. An apparatus as defined in claim 19, wherein said light energy sources are tilted from about 6 degrees to about 12 degrees toward said axis.

29. An apparatus as defined in claim 19, wherein said circular reflector is gold plated.

30. An apparatus for heat treating semiconductor wafers comprising:

a thermal processing chamber, said thermal processing containing at least one sidewall, an upper wall, and a lower wall;

a substrate holder contained in said thermal processing chamber for holding a semiconductor wafer, said substrate holder being configured to rotate said wafer;

a heating device in communication with said thermal processing chamber for heating a semiconductor wafer held on said substrate holder using electromagnetic energy, said heating device comprising at least one heating cone and having an axis perpendicular to said semiconductor wafer, said heating cone including a plurality of light energy sources positioned within a conically-shaped reflector, said conically-shaped reflector gradually decreasing in diameter in a direction towards said semiconductor wafer, at least certain of said light energy sources contained within said conically-shaped reflector being tilted towards said axis defined by said heating cone an amount up to about 20 degrees;

a window separating said heating device from said thermal processing chamber, said window being disposed on either said upper wall or said lower wall of said thermal processing chamber;

at least one temperature sensing device for sensing the temperature of said wafer at least at one location; and

a controller in communication with said at least one temperature sensing device and said light energy sources, said controller being configured to control the amount of electromagnetic energy being emitted by said light energy sources in response to temperature information received from said at least one temperature sensing device.

31. An apparatus as defined in claim 30, wherein said light energy sources have a determined length and wherein said conically-shaped reflector extends beyond the length of said light energy sources.

32. An apparatus as defined in claim 30, wherein said heating device further comprises concentric rings of light energy sources surrounding said heating cone.

33. An apparatus as defined in claim 30, wherein at least six light energy sources are contained within said conically-shaped reflector.

34. An apparatus as defined in claim 30, further comprising a reflective top enclosing said conically-shaped reflector.