Methods and systems for determining a thickness of a structure on a specimen and at least one additional property of the specimen

• US 6,950,196 B2
• Filed: 09/20/2001
• Issued: 09/27/2005
• Est. Priority Date: 09/20/2000
• Status: Expired due to Term

• Current Assignee: KLA-Tencor Corporation (KLA Corporation)
• Original Assignee: Kla-Tencor Technologies Corporation (KLA Corporation)
• Inventors: Levy, Ady, Wack, Dan, Fielden, John, Bultman, Gary, Brown, Kyle A., Nikoonahad, Mehrdad
• Primary Examiner(s): Lauchman, Layla
• Application Number:
  US09/956,841
• Publication Number:
  US 20020097406A1
• Time in Patent Office: 1,468 Days
• Field of Search: 356/369, 356/432, 356/417, 356/319, 356/445, 356/381, 356/345, 356/630, 356/625, 3562371-2375, 250/225, 250/226, 738/00
• US Class Current: 356/630
• CPC Class Codes: G01N 2021/646 Detecting fluorescent inhomogeneities at a position, e.g. for detecting defects
• CPC Class Codes: G01N 2021/8825 Separate detection of dark field and bright field
• CPC Class Codes: G01N 21/211 Ellipsometry optical thickness measurement G01B11/06
• CPC Class Codes: G01N 21/47 Scattering, i.e. diffuse reflection G01N21/25, G01N21/41 take precedence G01N21/55 takes precedence
• CPC Class Codes: G01N 21/55 Specular reflectivity
• CPC Class Codes: G01N 21/636 using an arrangement of pump beam and probe beam; using the measurement of optical non-linear properties; non-linear optics per se G02F1/35
• CPC Class Codes: G01N 21/64 Fluorescence; Phosphorescence
• CPC Class Codes: G01N 21/94 Investigating contamination, e.g. dust G01N21/85 takes precedence
• CPC Class Codes: G01N 21/9501 Semiconductor wafers manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G01N 21/9503 Wafer edge inspection
• CPC Class Codes: G01N 21/956 Inspecting patterns on the surface of objects contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G03F 7/70616 Monitoring the printed patterns
• CPC Class Codes: G03F 7/70625 Dimensions, e.g. line width, critical dimension [CD], profile, sidewall angle or edge roughness
• CPC Class Codes: G03F 7/70633 Overlay, i.e. relative alignment between patterns printed by separate exposures in different layers, or in the same layer in multiple exposures or stitching
• CPC Class Codes: G03F 7/7065 Defects, e.g. optical inspection of patterned layer for defects
• CPC Class Codes: G03F 7/70658 Electrical testing
• CPC Class Codes: G03F 7/707 Chucks, e.g. chucking or un-chucking operations or structural details
• CPC Class Codes: G03F 7/70708 being electrostatic; Electrostatically deformable vacuum chucks
• CPC Class Codes: H01J 2237/31701 Ion implantation
• CPC Class Codes: H01L 22/12 for structural parameters, e.g. thickness, line width, refractive index, temperature, warp, bond strength, defects, optical inspection, electrical measurement of structural dimensions, metallurgic measurement of diffusions electrical measurement of diffusions H01L22/14
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: Y10T 117/1004 : with means for measuring, testing, or sensing

Abstract

Methods and systems for monitoring semiconductor fabrication processes are provided. A system may include a stage configured to support a specimen and coupled to a measurement device. The measurement device may include an illumination system and a detection system. The illumination system and the detection system may be configured such that the system may be configured to determine multiple properties of the specimen. For example, the system may be configured to determine multiple properties of a specimen including, but not limited to, a thickness of a structure on a specimen and at least one additional property of the specimen. In this manner, a measurement device may perform multiple optical and/or non-optical metrology and/or inspection techniques.

Claims

1. A system configured to determine at least two properties of a specimen during use, comprising:

a stage configured to support the specimen during use;

two or more measurement devices coupled to the stage, wherein the two or more measurement devices are configured to generate one or more output signals in response to one or more of the at least two properties of the specimen during use; and

a processor coupled to the two or more measurement devices, wherein the processor is configured to determine the at least two properties of the specimen from the one or more output signals during use, wherein the at least two properties comprise a thickness of a structure on the specimen and at least one additional property of the specimen, and wherein the two or more measurement devices are selected to provide the one or more output signals for different ranges of the thickness of the structure.

2. The system of claim 1, wherein the stage is further configured to move laterally during use.

3. The system of claim 1, wherein the stage is further configured to move rotatably during use.

4. The system of claim 1, wherein the stage is further configured to move laterally and rotatably during use.

5. The system of claim 1, wherein the two or more measurement devices comprise a small-spot photo-acoustic device and a grazing X-ray reflectometer.

6. The system of claim 1, wherein the two or more measurement devices comprise a small-spot photo-acoustic device and a broadband small-spot spectroscopic ellipsometer.

7. The system of claim 1, further comprising a pattern recognition system coupled to the stage and the processor, wherein the pattern recognition system is configured to generate one or more output signals during use, and wherein the processor is further configured to process the one or more output signals from the pattern recognition system during use.

8. The system of claim 1, wherein at least one element of a first of the two or more measurement devices comprises at least one element of a second of the two or more measurement devices.

9. The system of claim 1, wherein the at least one additional property is selected from the group consisting of an index of refraction, a velocity of sound, a density, a critical dimension, and a profile of a layer or a feature formed on the specimen.

10. The system of claim 1, wherein the structure comprises a single layer formed on the specimen.

11. The system of claim 1, wherein the structure comprises a single layer formed on the specimen, and wherein the single layer is selected from the group consisting of a substantially transparent film, a semi-transparent film, and an opaque metal film.

12. The system of claim 1, wherein the structure comprises multiple layers formed on the specimen.

13. The system of claim 1, wherein the structure comprises multiple layers formed on the specimen, and wherein the multiple layers comprise two or more layers selected from the group consisting of a substantially transparent film, a semi-transparent film, an opaque metal film, and any combination thereof.

14. The system of claim 1, wherein the specimen comprises a blanket wafer.

15. The system of claim 1, wherein the specimen comprises a patterned wafer.

16. The system of claim 1, further comprising a handling robot configured to dispose the specimen on the stage, wherein the handling robot is coupled to the two or more measurement devices.

17. The system of claim 1, further comprising a power supply, wherein the power supply is coupled to the two or more measurement devices.

18. The system of claim 1, further comprising an autofocus mechanism, wherein the autofocus mechanism is configured to bring the specimen substantially into focus for the two or more measurement devices.

19. The system of claim 1, wherein the system is coupled to a chemical-mechanical polishing tool.

20. The system of claim 1, wherein the system is further configured to determine the at least two properties of the specimen substantially simultaneously during use.

21. The system of claim 1, wherein the two or more measurement devices are further configured to generate the one or more output signals in response to the one or more of the at least two properties of the specimen at multiple locations on the surface of the specimen substantially simultaneously such that the one or more of the at least two properties of the specimen can be determined at the multiple locations substantially simultaneously.

22. The system of claim 1, wherein the system is coupled to a process tool, and wherein the system is disposed within the process tool.

23. The system of claim 1, wherein the system is coupled to a process tool, and wherein the system is arranged laterally proximate to the process tool.

24. The system of claim 1, wherein the system is coupled to a process tool, and wherein the process tool comprises a wafer handler configured to move the specimen to the stage during use.

25. The system of claim 1, wherein the system is coupled to a process tool, and wherein the stage is further configured to move the specimen from the system to the process tool during use.

26. The system of claim 1, wherein the system is coupled to a process tool, and wherein the stage is further configured to move the specimen to a process chamber of the process tool during use.

27. The system of claim 1, wherein the system is coupled to a process tool, and wherein the system is further configured to determine at least the two properties of the specimen while the specimen is waiting between process steps.

28. The system of claim 1, wherein the system is coupled to a process tool, wherein the process tool comprises a support device configured to support the specimen during a process step, and wherein an upper surface of the support device is substantially parallel to an upper surface of the stage.

29. The system of claim 1, wherein the system is coupled to a process tool, wherein the process tool comprises a support device configured to support the specimen during a process step, and wherein an upper surface of the stage is angled with respect to an upper surface of the support device.

30. The system of claim 1, wherein the system further comprises a measurement chamber, wherein the stage and the two or more measurement devices are disposed within the measurement chamber, and wherein the measurement chamber is coupled to a process tool.

31. The system of claim 1, wherein the system further comprises a measurement chamber, wherein the stage and the two or more measurement devices are disposed within the measurement chamber, wherein the measurement chamber is coupled to a process tool, and wherein the measurement chamber is disposed within the process tool.

32. The system of claim 1, wherein the system further comprises a measurement chamber, wherein the stage and the two or more measurement devices are disposed within the measurement chamber, wherein the measurement chamber is coupled to a process tool, and wherein the measurement chamber is arranged laterally proximate to a process chamber of the process tool.

33. The system of claim 1, wherein the system further comprises a measurement chamber, wherein the stage and the two or more measurement devices are disposed within the measurement chamber, wherein the measurement chamber is coupled to a process tool, and wherein the measurement chamber is arranged vertically proximate to a process chamber of the process tool.

34. The system of claim 1, wherein a process tool comprises a process chamber, wherein the stage is disposed within the process chamber, and wherein the stage is further configured to support the specimen during a process step.

35. The system of claim 1, wherein a process tool comprises a process chamber, wherein the stage is disposed within the process chamber, wherein the stage is further configured to support the specimen during a process step, and wherein the processor is further configured to determine the at least two properties of the specimen during the process step.

36. The system of claim 1, wherein a process tool comprises a process chamber, wherein the stage is disposed within the process chamber, wherein the stage is further configured to support the specimen during a process step, wherein the processor is further configured to obtain a signature characterizing the process step during use, and wherein the signature comprises at least one singularity representative of an end of the process step.

37. The system of claim 1, wherein a process tool comprises a process chamber, wherein the stage is disposed within the process chamber, wherein the stage is further configured to support the specimen during a process step, wherein the processor is further coupled to the process tool and is further configured to alter a parameter of one or more instruments coupled to the process tool in response to the one or more of the at least two properties using an in situ control technique during use.

38. The system of claim 1, wherein a process tool comprises a first process chamber and a second process chamber, and wherein the stage is further configured to move the specimen from the first process chamber to the second process chamber during use.

39. The system of claim 1, wherein a process tool comprises a first process chamber and a second process chamber, wherein the stage is further configured to move the specimen from the first process chamber to the second process chamber during use, and wherein the processor is further configured to determine at least the two properties of the specimen as the stage is moving the specimen from the first process chamber to the second process chamber.

40. The system of claim 1, wherein the processor is further configured to compare the at least two properties of the specimen and properties of a plurality of specimens during use.

41. The system of claim 1, wherein the processor is further configured to compare the one or more of the at least two properties of the specimen to a predetermined range for the one or more properties during use.

42. The system of claim 1, wherein the processor is further configured to compare the one or more of the at least two properties of the specimen to a predetermined range for the one or more properties during use, and wherein the processor is further configured to generate an output signal if the one or more properties of the specimen are outside of the predetermined range during use.

43. The system of claim 1, wherein the processor is further configured to alter a sampling frequency of at least one of the two or more measurement devices in response to one or more of the at least two properties during use.

44. The system of claim 1, wherein the processor is further configured to alter a parameter of one or more instruments coupled to at least one of the two or more measurement devices in response to the one or more of the at least two properties using a feedback control technique during use.

45. The system of claim 1, wherein the processor is further configured to alter a parameter of one or more instruments coupled to at least one of the two or more measurement devices in response to the one or more of the at least two properties using a feedforward control technique during use.

46. The system of claim 1, wherein the processor is further configured to generate a database during use, and wherein the database comprises the at least two properties of the specimen.

47. The system of claim 1, wherein the processor is further configured to generate a database during use, wherein the database comprises the at least two properties of the specimen, and wherein the processor is further configured to calibrate the two or more measurement devices using the database during use.

48. The system of claim 1, wherein the processor is further configured to generate a database during use, wherein the database comprises the at least two properties of the specimen, and wherein the processor is further configured to monitor the one or more output signals generated by the two or more measurement devices using the database during use.

49. The system of claim 1, wherein the processor is further configured to generate a database during use, wherein the database comprises the at least two properties of the specimen and at least two properties of a plurality of specimens, wherein the at least two properties of the plurality of specimens are determined using a plurality of measurement devices, wherein the processor is further coupled to the plurality of measurement devices, and wherein the processor is further configured to calibrate the plurality of measurement devices using the database during use.

50. The system of claim 1, wherein the processor is further configured to generate a database during use, wherein the database comprises the at least two properties of the specimen and at least two properties of a plurality of specimens, wherein the at least two properties of the plurality of specimens are determined using a plurality of measurement devices, wherein the processor is further coupled to the plurality of measurement devices, and wherein the processor is further configured to monitor output signals generated by the plurality of measurement devices using the database during use.

51. The system of claim 1, further comprising a stand alone system coupled to the system, wherein the stand alone system is configured to be calibrated with a calibration standard during use, and wherein the stand alone system is further configured to calibrate the system during use.

52. The system of claim 1, further comprising a stand alone system coupled to the system and at least one additional system, wherein the stand alone system is configured to be calibrated with a calibration standard during use, and wherein the stand alone system is further configured to calibrate the system and at least the one additional system during use.

53. The system of claim 1, wherein the system is further configured to determine the one or more of the at least two properties of the specimen at more than one position on the specimen, wherein the specimen comprises a wafer, and wherein the processor is further configured to alter at least one parameter of one or more instruments coupled to a process tool in response to the one or more of the at least two properties of the specimen at the more than one position on the specimen to reduce within wafer variation of the one or more properties.

54. The system of claim 1, wherein the processor is further coupled to a process tool, and wherein the processor is further configured to alter a parameter of one or more instruments coupled to the process tool in response to one or more of the at least two properties using a feedback control technique during use.

55. The system of claim 1, wherein the processor is further coupled to a process tool, and wherein the processor is further configured to alter a parameter of one or more instruments coupled to the process tool in response to one or more of the at least two properties using a feedforward control technique during use.

56. The system of claim 1, wherein the processor is further coupled to a process tool, and wherein the processor is further configured to monitor a parameter of one or more instruments coupled to the process tool during use.

57. The system of claim 56, wherein the processor is further configured to determine a relationship between the one or more of the at least two properties and at least one of the monitored parameters during use.

58. The system of claim 57, wherein the processor is further configured to alter the at least one of the monitored parameters in response to the determined relationship during use.

59. The system of claim 1, wherein the processor comprises a local processor coupled to the two or more measurement devices and a remote controller computer coupled to the local processor, wherein the local processor is configured to at least partially process the one or more output signals during use, and wherein the remote controller computer is configured to further process the at least partially processed one or more output signals during use.

60. The system of claim 59, wherein the local processor is further configured to determine the at least two properties of the specimen during use.

61. The system of claim 59, wherein the remote controller computer is further configured to determine the at least two properties of the specimen during use.

62. A method determining at least two properties of a specimen, comprising:

disposing the specimen upon a stage, wherein the stage is coupled to two or more measurement devices;

generating one or more output signals with the two or more measurement devices, wherein the one or more output signals are responsive to the at least two properties of the specimen; and

processing the one or more output signals to determine the at least two properties of the specimen, wherein the at least two properties of the specimen comprise a thickness of a structure on the specimen and at least one additional property of the specimen, and wherein the one or more output signals that are processed are selected to be the one or more output signals provided by one of the two or more measurement devices depending on the thickness of the structure.

63. A computer-implemented method for controlling a system configured to determine at least two properties of a specimen during use, wherein the system comprises a stage coupled to two or more measurement devices, and wherein the stage is configured to support the specimen during use, the method comprising:

controlling the two or more measurement devices to generate one or more output signals responsive to the at least two properties of the specimen; and

processing the one or more output signals to determine the at least two properties of the specimen, wherein the at least two properties of the specimen comprise a thickness of a structure on the specimen and at least one additional property of the specimen, and wherein the one or more output signals that are processed are selected to be the one or more output signals provided by one of the two or more measurement devices depending on the thickness of the structure.

64. A method for fabricating a semiconductor device, comprising:

forming a portion of the semiconductor device upon a specimen;

disposing the specimen upon a stage, wherein the stage is coupled to two or more measurement devices;

generating one or more output signals with the two or more measurement devices, wherein the one or more output signals are responsive to at least two properties of the specimen; and

processing the one or more output signals to determine the at least two properties of the specimen, wherein the at least two properties of the specimen comprise a thickness of a structure on the specimen and at least one additional property of the specimen, and wherein the one or more output signals that are processed selected to be the one or more output signals provided by one of the two or more measurement devices depending on the thickness of the structure.

65. A system configured to determine at least two properties of a specimen during use, comprising:

a stage configured to support the specimen during use;

two or more measurement devices coupled to the stage, wherein the two or more measurement devices are configured to generate one or more output signals in response to one or more of the at least two properties of the specimen during use;

a local processor coupled to the two or more measurement devices and configured to at least partially process the one or more output signals during use; and

a remote controller computer coupled to the local processor, wherein the remote controller computer is configured to receive the at least partially processed one or more output signals and to determine the at least two properties of the specimen from the at least partially processed one or more output signals during use, wherein the at least two properties comprise a thickness of a structure on the specimen and at least one additional property of the specimen, and wherein the two or more measurement devices are selected to provide the one or more output signals for different ranges of the thickness of the structure.

66. A method for determining at least two properties of a specimen, comprising:

disposing the specimen upon a stage, wherein the stage is coupled to two or more measurement devices;

generating one or more output signals with the two or more measurement devices, wherein the one or more output signals are responsive to the at least two properties of the specimen; and

processing the one or more output signals to determine the at least two properties of the specimen, wherein the at least two properties of the specimen comprise a thickness of a structure on the specimen and at least one additional property of the specimen, wherein the one or more output signals that are processed are selected to be the one or more output signals provided by one of the two or more measurement devices depending on the thickness of the structure, and wherein processing the one or more output signals comprises;

at least partially processing the one or more output signals using a local processor, wherein the local processor is coupled to the two or more measurement devices;

sending the at least partially processed one or more output signals from the local processor to a remote controller computer; and

further processing the at least partially processed one or more output signals using the remote controller computer.

67. A system configured to determine at least two properties of a specimen, comprising:

a first measurement device configured to measure a thickness and at least one additional property of a layer on the specimen; and

a second measurement device configured to measure the thickness and at least another additional property of the layer on the specimen, wherein the second measurement device comprises a photo-acoustic device, and wherein the first and second measurement devices are selected to provide measurements for different ranges of the thickness of the layer.

68. The system of claim 67, wherein the layer allows at least some light to pass through the layer.

69. The system of claim 67, wherein the layer comprises a conductive layer having a thickness such that at least some light can pass through the layer.

70. The system of claim 67, wherein the layer comprises copper having a thickness such that at least some light can pass through the copper.

71. The system of claim 67, wherein the first measurement device comprises an ellipsometer.

72. The system of claim 67, wherein the first measurement device comprises a broadband spectroscopic ellipsometer.

73. The system of claim 67, wherein the first measurement device comprises a reflectometer.