Ion sources, systems and methods

• US 7,786,451 B2
• Filed: 11/15/2006
• Issued: 08/31/2010
• Est. Priority Date: 10/16/2003
• Status: Active Grant

• Current Assignee: Alis Corp. (Carl-Zeiss-Stiftung)
• Original Assignee: Alis Corp. (Carl-Zeiss-Stiftung)
• Inventors: Notte, John A. IV, Hill, Raymond, Farkas, Louis S. III, Groholski, Alexander, Comunale, Richard, Ward, Billy W., Percival, Randall G.
• Primary Examiner(s): Wells; Nikita
• Application Number:
  US11/599,973
• Publication Number:
  US 20070158582A1
• Time in Patent Office: 1,385 Days
• Field of Search: 250/423.F, 250/423.R, 250/426, 250/424, 250/423
• US Class Current: 250/423.00F
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: H01J 2237/0807 Gas field ion sources [GFIS]
• CPC Class Codes: H01J 2237/202 Movement
• CPC Class Codes: H01J 2237/20228 Mechanical X-Y scanning
• CPC Class Codes: H01J 2237/2566 ion
• CPC Class Codes: H01J 2237/2623 Field-emission microscopes
• CPC Class Codes: H01J 2237/2812 Emission microscopes
• CPC Class Codes: H01J 2237/30438 Registration
• CPC Class Codes: H01J 2237/3174 Etching microareas
• CPC Class Codes: H01J 2237/31755 using ion beams
• CPC Class Codes: H01J 27/26 using surface ionisation, e.g. field effect ion sources, thermionic ion sources H01J27/20, H01J27/24 take precedence
• CPC Class Codes: H01J 37/08 Ion sources; Ion guns
• CPC Class Codes: H01J 37/20 Means for supporting or positioning the object or the material; Means for adjusting diaphragms or lenses associated with the support
• CPC Class Codes: H01J 37/252 Tubes for spot-analysing by electron or ion beams; Microanalysers
• CPC Class Codes: H01J 37/28 with scanning beams H01J37/268, H01J37/292, H01J37/2955 take precedence
• CPC Class Codes: H01J 37/3056 for microworking, e. g. etching of gratings or trimming of electrical components
• CPC Class Codes: H01J 37/3174 Particle-beam lithography, e.g. electron beam lithography

Abstract

Ion sources, systems and methods are disclosed.

Claims

1. A system, comprising:

a gas field ion source having an electrically conductive tip with a terminal shelf comprising one or more atoms,

wherein the system is configured so that, during use of the system, the one or more atoms interact with a gas to generate an ion beam, and 70% or more of the ions in the ion beam that reach a surface of a sample are generated via an interaction of the gas with only one atom of the one or more atoms.

2. The system of claim 1, wherein, during use, 75% or more of the ions in the ion beam that reach a surface of a sample are generated via an interaction of the gas with only one atom of the one or more atoms.

3. The system of claim 1, wherein, during use, 80% or more of the ions in the ion beam that reach a surface of a sample are generated via an interaction of the gas with only one atom of the one or more atoms.

4. The system of claim 1, wherein, during use, 85% or more of the ions of the ions in the ion beam that reach a surface of a sample are generated via an interaction of the gas with only one atom of the one or more atoms.

5. The system of claim 1, further comprising ion optics that include electrodes and an aperture.

6. The system of claim 5, wherein the aperture is a disk.

7. The system of claim 5, wherein the aperture has multiple openings.

8. The system of claim 1, wherein the terminal shelf comprises 20 atoms or less.

9. The system of claim 1, wherein the terminal shelf is a trimer.

10. The system of claim 1, wherein the electrically conductive tip has an average radius of curvature of 200 nm or less.

11. The system of claim 1, wherein the electrically conductive tip has an average full cone angle of from 15°

to 45°

.

12. The system of claim 1, the electrically conductive tip has average cone direction of 10°

or less.

13. The system of claim 1, wherein the electrically conductive tip includes an end that comprises a single crystal that is aligned with a longitudinal axis of the electrically conductive to within 3°

or less.

14. The system of claim 1, wherein the electrically conductive tip comprises a material selected from the group consisting of tungsten, carbon, tantalum, iridium, rhenium, niobium, platinum and molybdenum.

15. The system of claim 1, wherein the electrically conductive tip is a tungsten tip.

16. The system of claim 1, wherein the electrically conductive tip is a W(111) tip.

17. The system of claim 16, wherein the terminal shelf is a trimer.

18. The system of claim 1, wherein the system is a gas field ion microscope.

19. The system of claim 1, wherein the system is a helium ion microscope.

20. The system of claim 1, wherein the system is a scanning ion microscope.

21. The system of claim 1, wherein the system is a scanning helium ion microscope.

22. The system of claim 1, further comprising a mechanism, the gas field ion source including an electrically conductive tip, the mechanism being coupled to the gas field ion source so that the mechanism can translate the electrically conductive tip, tilt the electrically conductive tip or both.

23. The system of claim 22, wherein the mechanism comprises a curved surface.

24. The system of claim 22, wherein the mechanism tilts the ion source relative to the aperture.

25. The system of claim 22, wherein the electrically conductive tip is a W(111) tip, and the terminal shelf is a trimer.

26. The system of claim 1, wherein the system is a gas field ion microscope having a damage test value is 25 nm or less.

27. The system of claim 1, wherein the system is a gas field ion microscope having a quality factor of 0.25 or more.

28. The system of claim 1, wherein the system is a gas field ion microscope that is capable of producing an image of a sample, the image of the sample having a resolution of 10 nm or less.

29. The system of claim 1, wherein the gas field ion source is capable of interacting with the gas to generate an ion beam for a time period of one week or more with a maximum interruption time of 10 hours or less.

30. The system of claim 1, wherein gas field ion source comprises an electrically conductive tip, the ion source being capable of interacting with the gas to generate the ion beam for a time period of one week or more without removing the electrically conductive tip from the system.

31. The system of claim 1, wherein the ion beam has a reduced etendue of 1×

10<sup>−

16</sup> cm²srV or less.

32. The system of claim 1, wherein the ion beam has an etendue of 5×

10<sup>−

21</sup> cm²sr or less.

33. The system of claim 1, wherein the ion beam has a reduced brightness at the surface of the sample of 5×

10⁸ A/m²srV or more.

34. The system of claim 1, wherein the ion beam has a brightness at the surface of the sample of 1×

10⁹ A/cm²sr or more.

35. The system of claim 1, wherein the ion beam has a spot size with a dimension of 10 nm or less at the surface of the sample.

36. The system of claim 1, wherein the ion beam has an ion beam current at the surface of the sample of one nA or less.

37. The system of claim 36, wherein the ion beam current at the surface of the sample is 0.1 fA or more.

38. The system of claim 1, wherein the ion beam has an energy spread at the surface of the sample of five eV or less.

39. The system of claim 1, further comprising the sample, wherein the gas field ion source including a tip, and the surface of the sample is five cm or more from the tip.

40. The system of claim 1, further comprising a coolant source thermally coupled to the gas field ion source so that during operation of the ion source the temperature of the ion source is 5K or more.

41. The system of claim 1, further comprising a cryogenic refrigerator source thermally coupled to the gas field ion source so that during operation of the ion source the temperature of the ion source is 5K or more.

42. The system of claim 1, wherein the ion beam having a convergence half angle of 5 mrad or less at a surface of the sample.

43. The system of claim 1, wherein the gas field ion source comprises an electrically conductive tip having a terminal shelf with 20 atoms or less.

44. A system, comprising:

a gas field ion source including an electrically conductive tip capable of interacting with a gas to generate an ion beam;

ion optics configured so that during use at least a portion of the ion beam passes through the ion optics; and

a moving mechanism coupled to the gas field ion source so that the moving mechanism can translate the electrically conductive tip, tilt the electrically conductive tip or both,

wherein the electrically conductive tip has a terminal shelf comprising 20 atoms or less.

45. The system of claim 44, wherein the moving mechanism includes a curved surface.

46. The system of claim 45, wherein the curved surface is spherical.

47. The system of claim 44, wherein the moving mechanism tilts the electrically conductive tip.

48. The system of claim 47, wherein the moving mechanism can tilt the gas field ion source in two independent directions.

49. The system of claim 44, wherein the moving mechanism translates the electrically conductive tip.

50. The system of claim 44, further comprising a support, the moving mechanism being mounted in the support.

51. The system of claim 50, wherein the moving mechanism includes a curved surface, and the support is configured to move relative to the curved surface of the moving mechanism.

52. The system of claim 44, wherein the electrically conductive tip has a terminal shelf comprising one or more atoms, and 70% or more of the ions in the ion beam that reach a surface of a sample are generated via an interaction between the gas and a single atom of the one or more atoms.

53. The system of claim 44, wherein the ion optics include electrodes and an aperture.

54. The system of claim 53, wherein the aperture is a disk.

55. The system of claim 53, wherein the aperture has multiple openings.

56. The system of claim 44, wherein the electrically conductive tip has a terminal shelf that is a trimer.

57. The system of claim 44, wherein the electrically conductive tip has an average radius of curvature of 200 nm or less.

58. The system of claim 44, wherein the electrically conductive tip has an average full cone angle of from 15°

to 45°

.

59. The system of claim 44, the electrically conductive tip has average cone direction of 10°

or less.

60. The system of claim 44, wherein the electrically conductive tip includes a single crystal terminal shelf that is aligned with a longitudinal axis of the electrically conductive tip to within 3°

or less.

61. The system of claim 44, wherein the electrically conductive tip comprises a material selected from the group consisting of tungsten, carbon, tantalum, iridium, rhenium, niobium, platinum and molybdenum.

62. The system of claim 44, wherein the electrically conductive tip is a tungsten tip.

63. The system of claim 44, wherein the electrically conductive tip is a W(111) tip.

64. The system of claim 63, wherein the W(111) tip has a terminal shelf that is a trimer.

65. The system of claim 44, wherein the system is a gas field ion microscope.

66. The system of claim 44, wherein the system is a helium ion microscope.

67. The system of claim 44, wherein the system is a scanning ion microscope.

68. The system of claim 44, wherein the system is a scanning helium ion microscope.

69. The system of claim 44, wherein the system is a gas field ion microscope having a damage test value is 25 nm or less.

70. The system of claim 44, wherein the system is a gas field ion microscope having a quality factor of 0.25 or more.

71. The system of claim 44, wherein the system is a gas field ion microscope that is capable of producing an image of a sample, the image of the sample having a resolution of 10 nm or less.

72. The system of claim 44, wherein the ion beam can operate for a time period of one week or more with a maximum interruption time of 10 hours or less.

73. The system of claim 44, wherein the ion microscope comprises an ion source that includes an electrically conductive tip, the ion source being capable of generating ions for a time period of one week or more without removing the electrically conductive tip from the system.

74. The system of claim 44, wherein the ion beam has a reduced etendue of 1×

10<sup>−

16</sup> cm ²srV or less.

75. The system of claim 44, wherein the ion beam has an etendue of 5×

10^-21 cm²sr or less.

76. The system of claim 44, wherein the ion beam has a reduced brightness at a surface of a sample of 5×

10⁸ A/m²srV or more.

77. The system of claim 44, wherein the ion beam has a brightness at a surface of a sample of 1×

10⁹ A/cm² sr or more.

78. The system of claim 44, wherein the ion beam has a spot size with a dimension of 10 nm or less at a surface of a sample.

79. The system of claim 44, wherein the ion beam has an ion beam current at a surface of a sample of one nA or less.

80. The system of claim 44, wherein the ion beam has an energy spread at a surface of a sample of five eV or less.

81. The system of claim 44, further comprising a sample, wherein the gas field ion source including a tip, and the surface of the sample is five cm or more from the tip.

82. The system of claim 44, further comprising a coolant source thermally coupled to the gas field ion source so that during operation of the ion source the temperature of the ion source is 5K or more.

83. The system of claim 44, further comprising a cryogenic refrigerator source thermally coupled to the gas field ion source so that during operation of the ion source the temperature of the ion source is 5K or more.

84. The system of claim 44, wherein the ion beam having a convergence half angle of 5 mrad or less at a surface of the sample.

85. The system of claim 44, wherein the gas field ion source comprises an electrically conductive tip having a terminal shelf with 20 atoms or less.

86. A system, comprising:

a gas field ion source including an electrically conductive tip with an average full cone angle of from 15°

to 45°

.

87. The system of claim 86, wherein the average full cone angle is from 20°

to 40°

.

88. The system of claim 86, wherein the average full cone angle is from 25°

to 35°

.

89. The system of claim 88, wherein the ion beam current at a surface of a sample is 0.1 fA or more.

90. The system of claim 86, wherein the average full cone angle is from 28°

to 32°

.

91. The system of claim 86, wherein the electrically conductive tip is a tip of a wire having a longitudinal axis, a dimension of the wire perpendicular to the longitudinal axis of the wire being three mm or less.

92. The system of claim 91, wherein the dimension of the wire perpendicular to the longitudinal axis of the wire is 0.2 mm or more.

93. The system of claim 86, wherein a standard deviation of the average full cone angle is 30% or less of the average full cone angle.

94. The system of claim 86, the electrically conductive tip has average cone direction of 10°

or less.

95. The system of claim 86, wherein the tip includes a single crystal terminal shelf that is aligned with the longitudinal axis of the electrically conductive tip to within 3°

or less.

96. The system of claim 86, wherein the electrically conductive tip comprises a material selected from the group consisting of tungsten, carbon, tantalum, iridium, rhenium, niobium, platinum and molybdenum.

97. The system of claim 86, wherein the electrically conductive tip is a tungsten tip.

98. The system of claim 86, wherein the electrically conductive tip is a W(111) tip.

99. The system of claim 86, further comprising ion optics capable of focusing onto a sample an ion beam generated via an interaction of a gas with the electrically conductive.

100. The system of claim 86, wherein the system is a gas field ion microscope.

101. The system of claim 86, wherein the system is a helium ion microscope.

102. The system of claim 86, wherein the system is a scanning ion microscope.

103. The system of claim 86, wherein the system is a scanning helium ion microscope.

104. A system, comprising:

a gas field ion source including an electrically conductive tip with an average radius of curvature of 200 nm or less,

wherein at least one of the following conditions is satisfied;

the electrically conductive tip has an average full cone angle of from 15°

to 45°

;

the electrically conductive tip has average cone direction of 10°

or less; and

the electrically conductive tip includes a single crystal terminal shelf that is aligned with the longitudinal axis of the electrically conductive tip to within 3°

or less.

105. The system of claim 104, wherein the electrically conductive tip has an average radius of curvature of 180 nm or less.

106. The system of claim 104, wherein the electrically conductive tip has an average radius of curvature of 170 nm or less.

107. The system of claim 104, wherein the electrically conductive tip has an average radius of curvature of 40 nm or more.

108. The system of claim 104, wherein the electrically conductive tip has an average full cone angle of from 15°

to 45°

.

109. The system of claim 104, wherein the electrically conductive wire is a tip of a wire having a longitudinal axis, a dimension of the wire perpendicular to the longitudinal axis of the wire being three mm or less.

110. The system of claim 109, wherein the dimension of the wire perpendicular to the longitudinal axis of the wire is 0.2 mm or more.

111. The system of claim 104, the electrically conductive tip has average cone direction of 10°

or less.

112. The system of claim 104, wherein the tip includes a single crystal terminal shelf that is aligned with the longitudinal axis of the electrically conductive tip to within 3°

or less.

113. The system of claim 104, wherein the electrically conductive tip comprises a material selected from the group consisting of tungsten, carbon, tantalum, iridium, rhenium, niobium, platinum and molybdenum.

114. The system of claim 104, wherein the electrically conductive tip is a tungsten tip.

115. The system of claim 104, wherein the electrically conductive tip is a W(111) tip.

116. The system of claim 104, further comprising ion optics capable of focusing onto a sample an ion beam generated via an interaction of a gas with the electrically conductive.

117. The system of claim 104, wherein the system is a gas field ion microscope.

118. The system of claim 104, wherein the system is a helium ion microscope.

119. The system of claim 104, wherein the system is a scanning ion microscope.

120. The system of claim 104, wherein the system is a scanning helium ion microscope.