Wafer out-of-pocket detector and susceptor leveling tool

• US 6,197,117 B1
• Filed: 07/23/1997
• Issued: 03/06/2001
• Est. Priority Date: 07/23/1997
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Vass, Curtis, Li, Shih-Hung
• Primary Examiner(s): Beck, Shrive
• Assistant Examiner(s): TORRES VELAZQUEZ, NORCA LIZ
• Application Number:
  US08/899,448
• Time in Patent Office: 1,322 Days
• Field of Search: 356/152.2, 356/139.1, 414/222, 414/936, 118/715, 118/728
• US Class Current: 118/715
• CPC Class Codes: H01L 21/681 using optical controlling means
• CPC Class Codes: Y10S 414/136 including wafer orienting means

Abstract

An apparatus and method for monitoring the level of a semiconductor processing chamber susceptor and the inclination of a wafer residing within a pocket of the susceptor. In one embodiment, a light beam transmitter is positioned to direct a light beam, such as a laser beam, onto the top surface of a wafer that has been positioned within a susceptor pocket. The light beam forms a target spot of a particular size and shape on the surface of the wafer. A camera is positioned to observe the target spot. A change in the angular orientation of the wafer or susceptor will result in a change in the size and shape of the target spot. The camera is configured to detect changes in the target spot size and shape. A logic circuit is provided at the output of the camera to correlate the observed shape and size of the target spot to a value indicative of the levelness of the susceptor and/or the inclination of a wafer located within the pocket of the susceptor. In another embodiment, the light beam is focused directly onto a surface of the susceptor. In this manner, the levelness and movement of the susceptor itself may be monitored.

Claims

1. An apparatus for monitoring the inclination of a wafer residing within a pocket of a susceptor in a semiconductor film deposition processing chamber, said apparatus comprising:

a light transmitter positioned to direct a light beam onto the top surface of said wafer, said light beam forming a target on said wafer surface during film deposition processing;

a detector for observing said target; and

a logic circuit coupled to said detector for correlating the shape or position of said target to the inclination of said wafer.

2. The apparatus of claim 1 wherein said logic circuit produces a signal indicative of the inclination of said wafer, said signal being provided to a wafer position indicator means.

3. The apparatus of claim 1 wherein said light transmitter is a laser transmitter and said light beam is a laser beam.

4. The apparatus of claim 3 wherein said laser beam has a wavelength of less than 680 nanometers.

5. The apparatus of claim 2 wherein said wafer position indicator means comprises a visual display.

6. The apparatus of claim 2 wherein said wafer position indicator means comprises an audible alarm.

7. The apparatus of claim 1 wherein said detector comprises a CCD.

8. The apparatus of claim 1 wherein said detector comprises a still photography camera.

9. The apparatus of claim 1 wherein said detector comprises an analog position sensor.

10. An apparatus for monitoring the film thickness on a substrate during film deposition processing, the apparatus comprising:

a light transmitter positioned to direct a light beam onto the top surface of said substrate, said light beam forming a target on said substrate surface during film deposition processing;

a detector for observing said target; and

a logic circuit coupled to said detector for correlating the shape or position of said target to the thickness of said film on said substrate.

11. The apparatus of claim 10 wherein said light transmitter is a laser transmitter and said light beam is a laser beam.

12. The apparatus of claim 11 wherein said detector comprises an analog position sensor.

13. The apparatus of claim 11 wherein said detector comprises a charged couple diode (CCD).

14. An apparatus for monitoring the levelness of a susceptor in a semiconductor film deposition processing chamber, the apparatus comprising:

a light transmitter positioned to direct a light beam onto a surface of said susceptor, said light beam forming a target on said surface during film deposition processing;

a detector for observing said target; and

a logic circuit coupled to said detector for correlating the shape or position of said target to the levelness of said susceptor.

15. The apparatus of claim 14 wherein said logic circuit produces a signal indicative of the levelness of said susceptor, said signal being provided to a susceptor level indicator means.

16. The apparatus of claim 14 wherein said detector comprises a CCD.

17. The apparatus of claim 14 wherein said detector comprises a still photography camera.

18. The apparatus of claim 14 wherein said detector comprises an analog position sensor.

19. An apparatus for monitoring the vertical position of a susceptor in a semiconductor film deposition processing chamber, the apparatus comprising:

a light source positioned to direct a light beam onto a surface of said susceptor, said light beam forming a target on said surface during film deposition processing;

a detector for observing said target; and

a logic circuit coupled to said detector for correlating the shape or position of said target to the vertical position of said susceptor.

20. The apparatus of claim 19 wherein said logic circuit produces a signal indicative of the vertical position of said susceptor, said signal being provided to a susceptor position indicator means.

21. The apparatus of claim 19 wherein said light source is a laser transmitter and said light beam is a laser beam.

22. The apparatus of claim 19 wherein said detector comprises a CCD.

23. The apparatus of claim 19 wherein said detector comprises a still photography camera.

24. The apparatus of claim 19 wherein said detector comprises an analog position sensor.

25. A semiconductor wafer processing assembly comprising:

a processing chamber having a susceptor, said susceptor having a pocket for holding a wafer;

a heat source for providing heat to the processing chamber;

an automated wafer handling system for positioning said wafer into said pocket of said susceptor, said wafer handling system being controlled by a controller;

a light transmitter positioned to direct a light beam onto the top surface of said wafer to produce a target;

a camera for observing said target; and

wafer position indicating means coupled to said camera.

26. The assembly of claim 25 further comprising a logic circuit coupled to said camera, said logic circuit correlating the shape of said target to the inclination of said wafer and producing an output signal indicative of the inclination of said wafer.

27. The assembly of claim 26 wherein said output signal is an input to said wafer handling system controller.

28. The assembly of claim 25 further comprising a logic circuit coupled to said camera, said logic circuit correlating the position of said target to the inclination of said wafer and producing an output signal indicative of the inclination of said wafer.

29. The assembly of claim 28 wherein said output signal is an input to said wafer handling system controller.

30. The assembly of claim 25 wherein said light transmitter and said camera are located outside said processing chamber.

31. An apparatus for monitoring the inclination of a wafer residing within a pocket of a semiconductor processing chamber susceptor, said apparatus comprising:

a heat source for providing heat to the processing chamber;

a light transmitter positioned to direct a light beam onto the top surface of said wafer, said light beam forming a target on said wafer surface, wherein said light transmitter is a laser transmitter and said light beam is a laser beam, wherein said laser beam has a wavelength of less than 680 nanometers;

a detector for observing said target; and

a logic circuit coupled to said detector for correlating the shape or position of said target to the inclination of said wafer.

32. The apparatus of claim 31 wherein said logic circuit produces a signal indicative of the inclination of said wafer, said signal being provided to a wafer position indicator.

33. The apparatus of claim 31 wherein said logic circuit produces a signal indicative of the inclination of said wafer, said signal being provided to a wafer handling system controller.

34. An apparatus for monitoring the inclination of a wafer residing within a pocket of a semiconductor processing chamber susceptor, said apparatus comprising:

a heat source for providing heat to the processing chamber;

a light transmitter positioned to direct a light beam onto the top surface of said wafer, said light beam forming a target on said wafer surface;

a detector for observing said target; and

a logic circuit coupled to said detector for correlating the shape or position of said target to the inclination of said wafer, wherein said logic circuit produces a signal indicative of the inclination of said wafer, said signal being provided to a wafer position indicator means, wherein said wafer position indicator means comprises a visual display.

35. The apparatus of claim 34 wherein said light transmitter is a laser transmitter and said light beam is a laser beam.

36. The apparatus of claim 35 wherein said laser beam has a wavelength of less than 680 nanometers.

37. An apparatus for monitoring the inclination of a wafer residing within a pocket of a semiconductor processing chamber susceptor, said apparatus comprising:

a heat source for providing heat to the processing chamber;

a light transmitter positioned to direct a light beam onto the top surface of said wafer, said light beam forming a target on said wafer surface;

a detector for observing said target, wherein said detector comprises a charged couple diode (CCD); and

a logic circuit coupled to said detector for correlating the shape or position of said target to the inclination of said wafer.

38. The apparatus of claim 37 wherein said logic circuit produces a signal indicative of the inclination of said wafer, said signal being provided to a wafer position indicator.

39. The apparatus of claim 37 wherein said logic circuit produces a signal indicative of the inclination of said wafer, said signal being provided to a wafer handling system controller.

40. The apparatus of claim 37 wherein said light transmitter is a laser transmitter and said light beam is a laser beam.

41. The apparatus of claim 40 wherein said laser beam has a wavelength of less than 680 nanometers.

42. An apparatus for monitoring the inclination of a wafer residing within a pocket of a semiconductor processing chamber susceptor, said apparatus comprising:

a heat source for providing heat to the processing chamber;

a light transmitter positioned to direct a light beam onto the top surface of said wafer, said light beam forming a target on said wafer surface;

a detector for observing said target, wherein said detector comprises an analog position sensor; and

a logic circuit coupled to said detector for correlating the shape or position of said target to the inclination of said wafer.

43. The apparatus of claim 42 wherein said logic circuit produces a signal indicative of the inclination of said wafer.

44. The apparatus of claim 43 wherein said signal is provided to a wafer position indicator.

45. The apparatus of claim 43 wherein said signal is provided to a wafer handling system controller.

46. The apparatus of claim 42 wherein said light transmitter is a laser transmitter and said light beam is a laser beam.

47. The apparatus of claim 46 wherein said laser beam has a wavelength of less than 680 nanometers.

48. An apparatus for monitoring the film thickness on a substrate comprising:

a processing chamber including a heat source for providing heat to the processing chamber;

a light transmitter positioned to direct a light beam onto the top surface of said substrate, said light beam forming a target on said substrate surface, wherein said light transmitter is a laser transmitter and said light beam is a laser beam;

a detector for observing said target; and

a logic circuit coupled to said detector for correlating the shape or position of said target to the thickness of said film on said substrate.

49. The apparatus of claim 48 wherein said logic circuit produces a signal indicative of the inclination of said wafer, said signal being provided to a wafer position indicator.

50. The apparatus of claim 48 wherein said logic circuit produces a signal indicative of the inclination of said wafer, said signal being provided to a wafer handling system controller.

51. An apparatus for monitoring the film thickness on a substrate comprising:

a processing chamber including a heat source for providing heat to the processing chamber;

a light transmitter positioned to direct a light beam onto the top surface of said substrate, said light beam forming a target on said substrate surface, wherein said light transmitter is a laser transmitter and said light beam is a laser beam;

a detector for observing said target, wherein said detector comprises an analog position sensor; and

a logic circuit coupled to said detector for correlating the shape or position of said target to the thickness of said film on said substrate.

52. The apparatus of claim 51 wherein said logic circuit produces a signal indicative of the inclination of said wafer, said signal being provided to a wafer position indicator.

53. The apparatus of claim 51 wherein said logic circuit produces a signal indicative of the inclination of said wafer, said signal being provided to a wafer handling system controller.

54. An apparatus for monitoring the film thickness on a substrate comprising:

a processing chamber including a heat source for providing heat to the processing chamber;

a light transmitter positioned to direct a light beam onto the top surface of said substrate, said light beam forming a target on said substrate surface, wherein said light transmitter is a laser transmitter and said light beam is a laser beam;

a detector for observing said target, wherein said detector comprises a charged couple diode (CCD); and

a logic circuit coupled to said detector for correlating the shape or position of said target to the thickness of said film on said substrate.

55. The apparatus of claim 54 wherein said logic circuit produces a signal indicative of the inclination of said wafer, said signal being provided to a wafer position indicator.

56. The apparatus of claim 54 wherein said logic circuit produces a signal indicative of the inclination of said wafer, said signal being provided to a wafer handling system controller.

57. An apparatus for monitoring the levelness of a semiconductor processing chamber susceptor comprising:

a heat source for providing heat to the processing chamber;

a light transmitter positioned to direct a light beam onto a surface of said susceptor, said light beam forming a target on said surface;

a detector for observing said target; and

a logic circuit coupled to said detector for correlating the shape or position of said target to the levelness of said susceptor, wherein said logic circuit produces a signal indicative of the levelness of said susceptor, said signal being provided to a susceptor level indicator.

58. The apparatus of claim 57 wherein said signal is provided to a susceptor level controller.

59. The apparatus of claim 57 wherein said light transmitter is a laser transmitter and said light beam is a laser beam.

60. The apparatus of claim 59 wherein said laser beam has a wavelength of less than 680 nanometers.

61. An apparatus for monitoring the levelness of a semiconductor processing chamber susceptor comprising:

a heat source for providing heat to the processing chamber;

a light transmitter positioned to direct a light beam onto a surface of said susceptor, said light beam forming a target on said surface;

a detector for observing said target, wherein said detector comprises a CCD;

a logic circuit coupled to said detector for correlating the shape or position of said target to the levelness of said susceptor.

62. The apparatus of claim 61 wherein said light transmitter is a laser transmitter and said light beam is a laser beam.

63. The apparatus of claim 62 wherein said laser beam has a wavelength of less than 680 nanometers.

64. The apparatus of claim 62 wherein said logic circuit produces a signal indicative of the levelness of said susceptor, said signal being provided to a susceptor level indicator.

65. The apparatus of claim 62 wherein said logic circuit produces a signal indicative of the levelness of said susceptor, said signal being provided to a susceptor level controller.

66. An apparatus for monitoring the levelness of a semiconductor processing chamber susceptor comprising:

a heat source for providing heat to the processing chamber;

a light transmitter positioned to direct a light beam onto a surface of said susceptor, said light beam forming a target on said surface;

a detector for observing said target, wherein said detector comprises an analog position sensor; and

a logic circuit coupled to said detector for correlating the shape or position of said target to the levelness of said susceptor.

67. The apparatus of claim 66 wherein said light transmitter is a laser transmitter and said light beam is a laser beam.

68. The apparatus of claim 67 wherein said laser beam has a wavelength of less than 680 nanometers.

69. The apparatus of claim 66 wherein said logic circuit produces a signal indicative of the levelness of said susceptor, said signal being provided to a susceptor level indicator.

70. The apparatus of claim 66 wherein said logic circuit produces a signal indicative of the levelness of said susceptor, said signal being provided to a susceptor level controller.

71. An apparatus for monitoring the vertical position of a semiconductor processing chamber susceptor comprising:

a heat source for providing heat to the processing chamber;

a light source positioned to direct a light beam onto a surface of said susceptor, said light beam forming a target on said surface;

a detector for observing said target; and

a logic circuit coupled to said detector for correlating the shape or position of said target to the vertical position of said susceptor, wherein said logic circuit produces a signal indicative of the vertical position of said susceptor, said signal being provided to a susceptor position indicator.

72. The apparatus of claim 71 wherein said light transmitter is a laser transmitter and said light beam is a laser beam.

73. The apparatus of claim 72 wherein said laser beam has a wavelength of less than 680 nanometers.

74. The apparatus of claim 71 wherein said signal is provided to a susceptor position controller.

75. An apparatus for monitoring the vertical position of a semiconductor processing chamber susceptor comprising:

a heat source for providing heat to the processing chamber;

a light source positioned to direct a light beam onto a surface of said susceptor, said light beam forming a target on said surface, wherein said light source is a laser transmitter and said light beam is a laser beam;

a detector for observing said target; and

a logic circuit coupled to said detector for correlating the shape or position of said target to the vertical position of said susceptor.

76. The apparatus of claim 75 wherein said laser beam has a wavelength of less than 680 nanometers.

77. The apparatus of claim 75 wherein said logic circuit produces a signal indicative of the vertical position of said susceptor, said signal being provided to a susceptor position indicator means.

78. The apparatus of claim 75 wherein said logic circuit produces a signal indicative of the vertical position of said susceptor, said signal being provided to a susceptor position controller means.

79. An apparatus for monitoring the vertical position of a semiconductor processing chamber susceptor comprising:

a heat source for providing heat to the processing chamber;

a light source positioned to direct a light beam onto a surface of said susceptor, said light beam forming a target on said surface;

a detector for observing said target, wherein said detector comprises a charged couple diode (CCD); and

a logic circuit coupled to said detector for correlating the shape or position of said target to the vertical position of said susceptor.

80. The apparatus of claim 79 wherein said logic circuit produces a signal indicative of the vertical position of said susceptor, said signal being provided to a susceptor position indicator means.

81. The apparatus of claim 79 wherein said logic circuit produces a signal indicative of the vertical position of said susceptor, said signal being provided to a susceptor position controller means.

82. The apparatus of claim 79 wherein said light transmitter is a laser transmitter and said light beam is a laser beam.

83. The apparatus of claim 82 wherein said laser beam has a wavelength of less than 680 nanometers.

84. An apparatus for monitoring the vertical position of a semiconductor processing chamber susceptor comprising:

a heat source for providing heat to the processing chamber;

a light source positioned to direct a light beam onto a surface of said susceptor, said light beam forming a target on said surface;

a detector for observing said target, wherein said detector comprises a still photography camera; and

a logic circuit coupled to said detector for correlating the shape or position of said target to the vertical position of said susceptor.

85. The apparatus of claim 84 wherein said logic circuit produces a signal indicative of the vertical position of said susceptor, said signal being provided to a susceptor position indicator means.

86. The apparatus of claim 84 wherein said logic circuit produces a signal indicative of the vertical position of said susceptor, said signal being provided to a susceptor position controller means.

87. The apparatus of claim 84 wherein said light transmitter is a laser transmitter and said light beam is a laser beam.

88. The apparatus of claim 87 wherein said laser beam has a wavelength of less than 680 nanometers.

89. An apparatus for monitoring the vertical position of a semiconductor processing chamber susceptor comprising:

a heat source for providing heat to the processing chamber;

a light source positioned to direct a light beam onto a surface of said susceptor, said light beam forming a target on said surface;

a detector for observing said target, wherein said detector comprises an analog position sensor; and

a logic circuit coupled to said detector for correlating the shape or position of said target to the vertical position of said susceptor.

90. The apparatus of claim 89 wherein said logic circuit produces a signal indicative of the vertical position of said susceptor, said signal being provided to a susceptor position indicator means.

91. The apparatus of claim 89 wherein said logic circuit produces a signal indicative of the vertical position of said susceptor, said signal being provided to a susceptor position controller means.

92. The apparatus of claim 89 wherein said light transmitter is a laser transmitter and said light beam is a laser beam.

93. The apparatus of claim 92 wherein said laser beam has a wavelength of less than 680 nanometers.