Method of monitoring anneal processes using scatterometry, and system for performing same

• US 6,933,158 B1
• Filed: 10/31/2002
• Issued: 08/23/2005
• Est. Priority Date: 10/31/2002
• Status: Expired due to Fees

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Stirton, James Broc, Lensing, Kevin R., Reeves, Steven P., Nariman, Homi E.
• Primary Examiner(s): SARKAR, ASOK K
• Application Number:
  US10/285,041
• Time in Patent Office: 1,027 Days
• Field of Search: 356445-448, 438/4, 438/14, 438/16, 438/17, 438/308, 438/514, 438/524
• US Class Current: 438/16
• CPC Class Codes: G01N 21/211 Ellipsometry optical thickness measurement G01B11/06
• CPC Class Codes: G01N 21/4788 Diffraction for sizing particles G01N15/0205
• CPC Class Codes: H01L 21/26513 of electrically active species
• CPC Class Codes: H01L 21/324 Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering H01L21/20 - H01L21/288 and H01L21/302 - H01L21/322 take precedence
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps
• CPC Class Codes: H01L 22/34 Circuits for electrically characterising or monitoring manufacturing processes, e. g. whole test die, wafers filled with test structures, on-board-devices incorporated on each die, process control monitors or pad structures thereof, devices in scribe line switching, multiplexing, gating devices G01R19/25; process control with lithography, e.g. dose control, G03F7/20; structures for alignment control by optical means G03F7/70633

Abstract

The present invention is directed to several inventive methods of monitoring anneal processes performed on implant regions, and a system for accomplishing same. In one aspect, the method comprises forming a first plurality of implant regions in a semiconducting substrate, performing at least one anneal process on implant regions, performing a scatterometric measurement of at least one of the implant regions after at least a portion of the anneal process is performed to determine a profile of the implant region and determining an effectiveness of the anneal process based upon the determined profile of the implant region. In other embodiments, one or more parameters of the anneal process may be varied on subsequently processed substrates based upon the determined efficiency of the anneal process.

Claims

1. A method of monitoring an anneal process performed on an implant region, comprising:

forming a first plurality of implant regions in a semiconducting substrate;

performing at least one anneal process on said first plurality of implant regions;

performing a scatterometric measurement of at least one of said first plurality of implant regions after at least a portion of said anneal process is performed to determine an implant profile of said at least one implant region; and

determining an effectiveness of said at least one anneal process based upon said determined profile of said at least one implant region.

2. The method of claim 1, wherein said at least one anneal process is performed in at least one of a furnace and a rapid thermal anneal chamber.

3. The method of claim 1, wherein said at least one anneal process is performed to activate dopant atoms implanted into said first plurality of implant regions.

4. The method of claim 1, wherein said at least one anneal process is performed at a temperature that ranges from approximately 1000-1200□

C.

5. The method of claim 1, wherein performing said scatterometric measurement of said at least one implant region comprises illuminating at least one of said first plurality of implant regions and measuring light reflected therefrom.

6. The method of claim 1, wherein performing said scatterometric measurement of said at least one implant region comprises:

generating a profile trace for said at least one implant region;

creating a profile trace for an anticipated profile of said at least one implant region; and

comparing said generated profile trace to said created profile trace.

7. The method of claim 6, wherein said created profile trace is created based upon assumed constant values for an index of refraction and a dielectric constant.

8. The method of claim 6, wherein values of at least one of an index of refraction and a dielectric constant are varied in creating said created profile trace.

9. The method of claim 6, further comprising modifying, based upon said comparison of said generated profile trace and said created profile trace, at least one parameter of an anneal process to be performed on implant regions formed on a subsequently processed substrate.

10. The method of claim 9, wherein modifying at least one parameter of said anneal process comprises modifying at least one of a temperature and a duration of said at least one anneal process.

11. The method of claim 1, further comprising creating a library comprised of a plurality of created profile traces, wherein said created profile traces are representative of implant regions having varying implant profiles.

12. The method of claim 1, wherein performing said scatterometric measurement of said at least one implant region comprises:

generating a profile trace for said at least one implant region;

creating a target profile trace for said at least one implant region; and

comparing said generated profile trace to said target profile trace.

13. The method of claim 12, wherein said target profile trace is created based upon assumed constant values for an index of refraction and a dielectric constant.

14. The method of claim 12, wherein values of at least one of an index of refraction and a dielectric constant are varied in creating said target profile trace.

15. The method of claim 12, further comprising modifying, based upon said comparison of said generated profile trace and said target profile trace, at least one parameter of an anneal process to be performed on implant regions formed on a subsequently processed substrate.

16. The method of claim 1, wherein forming a first plurality of implant regions in said substrate comprises forming a first plurality of implant regions to thereby define a grating structure in said substrate.

17. The method of claim 1, wherein said first plurality of implant regions are comprised of N type dopant material or P type dopant material.

18. The method of claim 1, wherein said first plurality of implant regions are illuminated using at least one of a multiple wavelength light source and a single wavelength light source.

19. The method of claim 1, wherein said determined implant profile is comprised of at least one of a width, a depth, a dopant concentration level, and a dopant concentration profile of said implant regions.

20. The method of claim 1, further comprising modifying, based upon said determined effectiveness of said at least one anneal process, at least one parameter of an anneal process to be performed on implant regions formed and on a subsequently processed substrate.

21. The method of claim 20, wherein modifying at least one parameter of said anneal process comprises modifying at least one of a temperature and a duration of said at least one anneal process.

22. The method of claim 1, wherein said scatterometric measurement employs constant values for an index of refraction and a dielectric constant.

23. The method of claim 1, wherein said scatterometric measurement employs varied values for at least one of an index of refraction and a dielectric constant.

24. The method of claim 23, wherein said values of at least one of said index of refraction and said dielectric constant are varied based upon depth.

25. The method of claim 1, wherein said scatterometric measurement is performed after said at least one anneal process is completed.

26. A method of monitoring an anneal process performed on an implant region, comprising:

forming a first plurality of implant regions in a semiconducting substrate;

performing at least one anneal process on said first plurality of implant regions;

performing a scatterometric measurement of at least one of said first plurality of implant regions after said anneal process is complete to determine an implant profile of said at least one implant region;

determining an effectiveness of said at least one anneal process based upon said determined profile of said at least one implant region; and

modifying, based upon said determined effectiveness of said at least one anneal process, at least one parameter of an anneal process to be performed on implant regions formed on a subsequently processed substrate.

27. The method of claim 26, wherein said at least one anneal process is performed in at least one of a furnace and a rapid thermal anneal chamber.

28. The method of claim 26, wherein said at least one anneal process is performed to activate dopant atoms implanted into said first plurality of implant regions.

29. The method of claim 26, wherein said at least one anneal process is performed at a temperature that ranges from approximately 1000-1200□

C.

30. The method of claim 26, wherein performing said scatterometric measurement of said at least one implant region comprises illuminating at least one of said fast plurality of implant regions and measuring light reflected therefrom.

31. The method of claim 26, wherein performing said scatterometric measurement of said at least one implant region comprises:

generating a profile trace for said at least one implant region;

creating a profile trace for an anticipated profile of said at least one implant region; and

comparing said generated profile trace to said created profile trace.

32. The method of claim 31, wherein said created profile trace is created based upon assumed constant values for an index of refraction and a dielectric constant.

33. The method of claim 31, wherein values of at least one of an index of refraction and a dielectric constant are varied in creating said created profile trace.

34. The method of claim 31, further comprising modifying, based upon said comparison of said generated profile trace and said created profile trace, at least one parameter of an anneal process to be performed on implant regions formed on a subsequently processed substrate.

35. The method of claim 34, wherein modifying at least one parameter of said anneal process comprises modifying at least one of a temperature and a duration of said at least one anneal process.

36. The method of claim 26, further comprising creating a library comprised of a plurality of created profile traces, wherein said created profile traces are representative of implant regions having varying implant profiles.

37. The method of claim 26, wherein performing said scatterometric measurement of said at least one implant region comprises:

generating a profile trace for said at least one implant region;

creating a target profile trace for said at least one implant region; and

comparing said generated profile trace to said target profile trace.

38. The method of claim 37, wherein said target profile trace is created based upon assumed constant values for an index of refraction and a dielectric constant.

39. The method of claim 37, wherein values of at least one of an index of refraction and a dielectric constant are varied in creating said target profile trace.

40. The method of claim 37, further comprising modifying, based upon said comparison of said generated profile trace and said target profile trace, at least one parameter of an anneal process to be performed on implant regions formed on a subsequently processed substrate.

41. The method of claim 26, wherein forming a first plurality of implant regions in said substrate comprises forming a first plurality of implant regions to thereby define a grating structure in said substrate.

42. The method of claim 26, wherein said first plurality of implant regions are comprised of N type dopant material or P type dopant material.

43. The method of claim 26, wherein said first plurality of implant regions are illuminated using at least one of a multiple wavelength light source and a single wavelength light source.

44. The method of claim 26, wherein said determined implant profile is comprised of at least one of a width, a depth, a dopant concentration level, and a dopant concentration profile of said implant regions.

45. The method of claim 26, wherein modifying at least one parameter of said anneal process comprises modifying at least one of a temperature and a duration of said at least one anneal process.

46. The method of claim 26, wherein said scatterometric measurement employs constant values for an index of refraction and a dielectric constant.

47. The method of claim 26, wherein said scatterometric measurement employs varied values for at least one of an index of refraction and a dielectric constant.

48. The method of claim 47, wherein said values of at least one of said index of refraction and said dielectric constant are varied based upon depth.

49. A method of monitoring an anneal process performed on an implant region, comprising:

forming a first plurality of implant regions in a semiconducting substrate;

performing at least one anneal process on said first plurality of implant regions;

performing a scatterometric measurement of at least one of said first plurality of implant regions after said anneal process is completed to determine an implant profile of said at least one implant region by;

generating a profile truce for said at least one implant region,

creating a plurality of profile traces, each of which correspond to an anticipated profile of said at least one implant region, and

comparing said generated profile trace to at least one of said created plurality of profile traces, and

determining an effectiveness of said at least one anneal process based upon said determined profile of said at least one implant region.

50. The method of claim 49, wherein said at least one anneal process is performed in at least one of a furnace and a rapid thermal anneal chamber.

51. The method of claim 49, wherein said at least one anneal process is performed to activate dopant atoms implanted into said first plurality of implant regions.

52. The method of claim 49, wherein said at least one anneal process is performed at a temperature that ranges from approximately 1000-1200□

C.

53. The method of claim 49, wherein performing said scatterometric measurement of said at least one implant region comprises illuminating at least one of said first plurality of implant regions and measuring light reflected therefrom.

54. The method of claim 49, wherein said plurality of profile trace is created based upon assumed constant values for an index of refraction and a dielectric constant.

55. The method of claim 49, wherein values of at least one of an index of refraction and a dielectric constant are varied in creating said plurality of profile traces.

56. The method of claim 49, further comprising creating a library comprised of said plurality of profile traces.

57. The method of claim 49, wherein forming a first plurality of implant regions in said substrate comprises forming a first plurality of implant regions to thereby define a grating structure in said substrate.

58. The method of claim 49, wherein said first plurality of implant regions are comprised of N type dopant material or P type dopant material.

59. The method of claim 49, wherein said first plurality of implant regions are illuminated using at least one of a multiple wavelength light source and a single wavelength light source.

60. The method of claim 49, wherein said determined implant profile is comprised of at least one of a width, a depth, a dopant concentration level, and a dopant concentration profile of said implant regions.

61. The method of claim 49, further comprising modifying, based upon said determined effectiveness of said at least one anneal process, at least one parameter of an anneal process to be performed on implant regions formed on a subsequently processed substrate.

62. The method of claim 61, wherein modifying at least one parameter of said anneal process comprises modifying at least one of a temperature and a duration of said at least one anneal process.

63. The method of claim 49, further comprising modifying, based upon said comparison of said generated profile trace and at least one of said created profile traces, at least one parameter of an anneal process to be performed on implant regions formed on a subsequently processed substrate.

64. The method of claim 63, wherein modifying at least one parameter of said anneal process comprises modifying at least one of a temperature and a duration of said at least one anneal process.

65. The method of claim 49, wherein said scatterometric measurement employs constant values for an index of refraction and a dielectric constant.

66. The method of claim 49, wherein said scatterometric measurement employs varied values for at least one of an index of refraction and a dielectric constant.

67. The method of claim 66, wherein said values of at least one of said index of refraction and said dielectric constant are varied based upon depth.

68. A method of monitoring an anneal process performed on an implant region, comprising:

forming a first plurality of implant regions in a semiconducting substrate;

performing at least one anneal process on said first plurality of implant regions;

performing a scatterometric measurement of at least one of said first plurality of implant regions after said anneal process is completed to determine an implant profile of said at least one implant region by;

generating a profile trace for said at least one implant region, creating a target profile trace for said at least one implant region, and comparing said generated profile trace to said target profile trace; and

determining an effectiveness of said at least one anneal process based upon said determined profile of said at least one implant region.

69. The method of claim 68, wherein said at least one anneal process is performed in at least one of a furnace and a rapid thermal anneal chamber.

70. The method of claim 68, wherein said at least one anneal process is performed to activate dopant atoms implanted into said first plurality of implant regions.

71. The method of claim 68, wherein said at least one anneal process is performed at a temperature that ranges from approximately 1000-1200□

C.

72. The method of claim 68, wherein performing said scatterometric measurement of said at least one implant region comprises illuminating at least one of said first plurality of implant regions and measuring light reflected therefrom.

73. The method of claim 68, wherein said target profile trace is created based upon assumed constant values for an index of refraction and a dielectric constant.

74. The method of claim 68, wherein values of at least one of an index of refraction and a dielectric constant are varied in creating said target profile trace.

75. The method of claim 68, further comprising modifying, based upon said comparison of said generated profile trace and said target profile trace, at least one parameter of an anneal process to be performed on implant regions formed on a subsequently processed substrate.

76. The method of claim 68, wherein forming a first plurality of implant regions in said substrate comprises forming a first plurality of implant regions to thereby define a grating structure in said substrate.

77. The method of claim 68, wherein said first plurality of implant regions are comprised of N type dopant material or P type dopant material.

78. The method of claim 68, wherein said first plurality of implant regions are illuminated using at least one of a multiple wavelength light source and a single wavelength light source.

79. The method of claim 68, wherein said determined implant profile is comprised of at least one of a width a depth, a dopant concentration level, and a dopant concentration profile of said implant regions.

80. The method of claim 68, further comprising modifying, based upon said determined effectiveness of said at least one anneal process, at least one parameter of an anneal process to be performed on implant regions formed on a subsequently processed substrate.

81. The method of claim 80, wherein modifying at least one parameter of said anneal process comprises modifying at least one of a temperature and a duration of said at least one anneal process.

82. The method of claim 68, wherein said scatterometric measurement employs constant values for an index of refraction and a dielectric constant.

83. The method of claim 68, wherein said scatterometric measurement employs varied values for at least one of an index of refraction and a dielectric constant.

84. The method of claim 83, wherein said values of at least one of said index of refraction and said dielectric constant are varied based upon depth.