Ion sources, systems and methods

• US 7,557,361 B2
• Filed: 11/15/2006
• Issued: 07/07/2009
• 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, Ward, Billy W., Percival, Randall G.
• Primary Examiner(s): Wells; Nikita
• Application Number:
  US11/600,874
• Publication Number:
  US 20070210251A1
• Time in Patent Office: 965 Days
• Field of Search: 250/423.F, 250/423.R, 250/424, 250/426, 250/492.21, 250/492.2
• 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: G01N 23/2255 using incident ion beams, e.g. proton beams
• 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 capable of interacting with a gas to generate an ion beam that can interact with a sample to cause scattered ions to leave the sample;

at least one detector configured so that, during use, the at least one detector can detect at least some of the scattered ions; and

an electronic processor electrically connected to the at least one detector so that, during use, the electronic processor can process information based on the detected scattered ions to determine information about the sample.

2. The system of claim 1, wherein the information about the sample is selected from the group consisting of topographical information about a surface of the sample, material constituent information of a surface of the sample, material constituent information about a sub-surface region of the sample, crystalline information about the sample, voltage contrast information about a surface of the sample, voltage contrast information about a sub-surface region of the sample, magnetic information about the sample, and optical information about the sample.

3. The system of claim 1, wherein the electronic processor can process information based on the detected scattered ions to determine information about the energy of the detected scattered ions.

4. The system of claim 3, wherein the information about the energy of the detected scattered ions is an energy distribution of the detected scattered ions.

5. The system of claim 3, wherein the electronic processor can process information based on the detected scattered ions to determine information about angles of trajectories of the detected scattered ions.

6. The system of claim 1, wherein the electronic processor can process information based on the detected scattered ions to determine information about angles of trajectories of the detected scattered ions.

7. The system of claim 6, wherein the information about the angles of the trajectories of the detected scattered ions is a distribution of the angles of the trajectories distribution of the detected scattered ions.

8. The system of claim 1, wherein the at least one detector comprises multiple detectors.

9. The system of claim 1, wherein the at least one detector is configured to provide angularly resolved information about the detected scattered ions.

10. The system of claim 9, wherein the at least one detector comprises multiple detectors that are located at different angles with respect to the sample.

11. The system of claim 9, wherein the at least one detector comprises a hemispherical detector.

12. The system of claim 9, wherein the at least one detector is capable of moving between a first solid angle with respect to the sample and a second solid angle with respect to the sample.

13. The system of claim 1, wherein, for a given scattered ion, the at least one detector is capable of providing a signal based on an energy of the given scattered ion.

14. The system of claim 13, wherein the at least one detector is configured to provide angularly resolved information about the detected scattered ions.

15. The system of claim 1, further comprising a device electrically connected within the system so that, during use, the ion beam is pulsed.

16. The system of claim 15, further comprising a time of flight sub-system configured so that, during use, the time of flight sub-system can measure time of flight information of the scattered ions.

17. The system of claim 1, further comprising a time of flight sub-system configured so that, during use, the time of flight sub-system can measure time of flight information of the scattered ions.

18. The system of claim 1, wherein, during use the ion beam impinges on a first surface of the sample, and at least one of the detectors is located adjacent to a second surface of the sample, the second surface being opposite the first surface.

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

10<sup>−

16</sup> cm²srV or less.

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

10<sup>−

21</sup> cm²sr or less.

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

10⁸ A/m²srV or more.

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

10⁹ A/cm²sr or more.

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

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

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

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

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

28. 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.

29. A method, comprising:

generating an ion beam by interacting a gas with a gas field ion source;

interacting the ion beam with a sample to cause scattered ions to leave the sample;

detecting at least some of the scattered ions; and

determining information about the sample based on the detected scattered ions.

32. The method of claim 29, wherein the information about the sample is selected from the group consisting of topographical information about a surface of the sample, material constituent information of a surface of the sample, material constituent information about a sub-surface region of the sample, crystalline information about the sample, voltage contrast information about a surface of the sample, voltage contrast information about a sub-surface region of the sample, magnetic information about the sample, and optical information about the sample.

33. The method of claim 29, further comprising determining information about energies of the detected scattered ions.

34. The method of claim 33, wherein the information about the energies of the detected scattered ions is an energy distribution of the detected scattered ions.

35. The method of claim 33, further comprising determining information about angles of trajectories of the detected scattered ions.

36. The method of claim 29, further comprising determining information about angles of trajectories of the detected scattered ions.

37. The method of claim 36, wherein the information about the angles of the trajectories of the detected scattered ions is a distribution of the angles of the trajectories of the detected scattered ions.

38. The method of claim 29, wherein the method includes using multiple detectors.

39. The method of claim 38, wherein the multiple detectors are located at different angles with respect to the sample.

40. The method of claim 29, wherein the method includes using a hemispherical detector.

41. The method of claim 38, further comprising moving one or more detectors from a first solid angle with respect to the sample to a second solid angle with respect to the sample.

42. The method of claim 29, further comprising pulsing the ion beam.

43. The method of claim 42, further comprising a time of flight sub-system configured so that, during use, the time of flight sub-system can measure time of flight information of the detected scattered ions.

44. The method of claim 29, further comprising a time of flight sub-system configured so that, during use, the time of flight sub-system can measure time of flight information of the detected scattered ions.

45. The method of claim 29, wherein, during use the ion beam impinges on a first surface of the sample, and at least one detector is located adjacent to a second surface of the sample, the second surface being opposite the first surface.

46. The method of claim 29, wherein the ion beam has a reduced etendue of 1×

10<sup>−

16</sup> cm²srV or less.

47. The method of claim 29, wherein the ion beam has an etendue of 5×

10<sup>−

21</sup> cm²sr or less.

48. The method of claim 29, wherein the ion beam has a reduced brightness at a surface of the sample of 5×

10⁸ A/m²srV or more.

49. The method of claim 29, wherein the ion beam has a brightness at a surface of the sample of 1×

10⁹A/cm²sr or more.

50. The method of claim 29, wherein the ion beam has a spot size with a dimension of 10 nm or less at a surface of the sample.

51. The method of claim 29, wherein the method is performed using a gas field ion microscope.

52. The method of claim 29, wherein the method is performed using is a helium ion microscope.

53. The method of claim 29, wherein the method is performed using is a scanning ion microscope.

54. The method of claim 29, wherein the method is performed using is a scanning helium ion microscope.

55. The method of claim 29, wherein the method can distinguish atoms in the sample having atomic numbers that differ by one.

56. The method of claim 29, wherein the method can distinguish atoms in the sample having masses that differ by one atomic mass unit.

30. A system, comprising:

a gas field ion source capable of interacting with a gas to generate an ion beam that can interact with a sample to cause primary neutral particles to leave the sample;

at least one detector configured so that, during use, the at least one detector can detect at least some of the primary neutral particles; and

an electronic processor electrically connected to the at least one detector so that, during use, the electronic processor can process information based on the detected primary neutral particles to determine information about the sample.

57. The system of claim 30, wherein the information about the sample is selected from the group consisting of topographical information about a surface of the sample, material constituent information of a surface of the sample, material constituent information about a sub-surface region of the sample, crystalline information about the sample, voltage contrast information about a surface of the sample, voltage contrast information about a sub-surface region of the sample, magnetic information about the sample, and optical information about the sample.

58. The system of claim 30, wherein the electronic processor can process information based on the detected primary neutral particles to determine information about the energy of the detected primary neutral particles.

59. The system of claim 58, wherein the information about the energy of the detected primary neutral particles is an energy distribution of the detected primary neutral particles.

60. The system of claim 58, wherein the electronic processor can process information based on the detected primary neutral particles to determine information about angles of trajectories of the detected primary neutral particles.

61. The system of claim 30, wherein the electronic processor can process information based on the detected primary neutral particles to determine information about angles of trajectories of the detected primary neutral particles.

62. The system of claim 61, wherein the information about the angles of the trajectories of the detected primary neutral particles is a distribution of the angles of the trajectories of the detected primary neutral particles.

63. The system of claim 30, wherein the at least one detector comprises multiple detectors.

64. The system of claim 30, wherein the at least one detector is configured to provide angularly resolved information about the detected primary neutral particles.

65. The system of claim 64, wherein the at least one detector comprises multiple detectors that are located at different angles with respect to the sample.

66. The system of claim 30, wherein the at least one detector comprises a hemispherical detector.

67. The system of claim 64, wherein the at least one detector is capable of moving between a first solid angle with respect to the sample and a second solid angle with respect to the sample.

68. The system of claim 30, wherein, for a given primary neutral particle, the at least one detector is capable of providing a signal based on an energy of the given primary neutral particle.

69. The system of claim 66, wherein the at least one detector is configured to provide angularly resolved information about the detected primary neutral particle.

70. The system of claim 30, further comprising a device electrically connected within the system so that, during use, the ion beam is pulsed.

71. The system of claim 70, further comprising a time of flight sub-system configured so that, during use, the time of flight sub-system can measure time of flight information of the primary neutral particles.

72. The system of claim 30, further comprising a time of flight sub-system configured so that, during use, the time of flight sub-system can measure time of flight information of the primary neutral particles.

73. The system of claim 30, wherein, during use the ion beam impinges on a first surface of the sample, and at least one of the detectors is located adjacent to a second surface of the sample, the second surface being opposite the first surface.

74. The system of claim 30, wherein, during use:

the gas field ion source interacts with the sample to cause additional particles to leave the sample, the additional particles being selected from the group consisting of electrons and scattered ions;

the at least one detector is configured to detect at least some of the scattered ions; and

the electronic processor can process information based on the detected scattered ions to determine information about the sample.

75. The system of claim 30, wherein the ion beam has a reduced etendue 1×

10<sup>−

16</sup> cm²srV or less.

76. The system of claim 30, wherein the ion beam has an etendue of 5×

10<sup>−

21</sup> cm²sr or less.

77. The system of claim 30, wherein the ion beam has a reduced brightness at the surface of a sample of 5×

10⁸ A/m²srV or more.

78. The system of claim 30, wherein the ion beam has a brightness at a surface of the sample of 1×

10⁹ A/cm²sr or more.

79. The system of claim 30, wherein the ion beam has a spot size with a dimension of 10 nm or less at a surface of the sample.

80. The system of claim 30, wherein the system is a gas field ion microscope.

81. The system of claim 30, wherein the system is a helium ion microscope.

82. The system of claim 30, wherein the system is a scanning ion microscope.

83. The system of claim 30, wherein the system is a scanning helium ion microscope.

84. The system of claim 30, wherein the gas field ion source comprises an electrically conductive tip having a terminal shelf with 20 atoms or less.

31. A method, comprising:

generating an ion beam by interacting a gas with a gas field ion source;

interacting the ion beam with a sample to cause primary neutral particles to leave the sample;

detecting at least some of the primary neutral particles; and

determining information about the sample based on the detected primary neutral particles.

85. The method of claim 31, wherein the information about the sample is selected from the group consisting of topographical information about a surface of the sample, material constituent information of a surface of the sample, material constituent information about a sub-surface region of the sample, crystalline information about the sample, voltage contrast information about a surface of the sample, voltage contrast information about a sub-surface region of the sample, magnetic information about the sample, and optical information about the sample.

86. The method of claim 31, further comprising determining information about energies of the detected primary neutral particles.

87. The method of claim 86, wherein the information about the energies of the detected scattered primary neutral particles is an energy distribution of the detected primary neutral particles.

88. The method of claim 86, further comprising determining information about angles of trajectories of the detected primary neutral particles.

89. The method of claim 31, further comprising determining information about angles of trajectories of the detected primary neutral particles.

90. The method of claim 89, wherein the information about the angles of the trajectories of the detected primary neutral particles is a distribution of the angles of the trajectories of the detected primary neutral particles.

91. The method of claim 31, wherein the method includes using multiple detectors.

92. The method of claim 91, wherein the multiple detectors are located at different angles with respect to the sample.

93. The method of claim 91, wherein the at least one detector comprises a hemispherical detector.

94. The method of claim 91, further comprising moving one or more detectors from a first solid angle with respect to the sample to a second solid angle with respect to the sample.

95. The method of claim 31, comprising pulsing the ion beam.

96. The method of claim 95, further comprising a time of flight sub-system configured so that, during use, the time of flight sub-system can measure time of flight information of the detected scattered primary neutral particles.

97. The method of claim 31, further comprising a time of flight sub-system configured so that, during use, the time of flight sub-system can measure time of flight information of the detected scattered primary neutral particles.

98. The method of claim 31, wherein, during use the ion beam impinges on a first surface of the sample, and at least one detector is located adjacent to a second surface of the sample, the second surface being opposite the first surface.

99. The method of claim 31, wherein interacting the ion beam with a sample forms scattered ions, and the method further comprises:

detecting at least some of the scattered ions; and

determining information about the sample based on the detected scattered ions.

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

10<sup>−

16</sup> cm²srV or less.

101. The method of claim 31, wherein the ion beam has an etendue of 5×

10<sup>−

21</sup> cm²sr or less.

102. The method of claim 31, wherein the ion beam has a reduced brightness at a surface of the sample of 5×

10⁸ A/m²srV or more.

103. The method of claim 31, wherein the ion beam has a brightness at a surface of the sample of 1¹⁰⁹ A/cm²sr or more.

104. The method of claim 31, wherein the ion beam has a spot size with a dimension of 10 nm or less at a surface of the sample.

105. The method of claim 31, wherein the method is performed using a gas field ion microscope.

106. The method of claim 31, wherein the method is performed using is a helium ion microscope.

107. The method of claim 31, wherein the method is performed using is a scanning ion microscope.

108. The method of claim 31, wherein the method is performed using is a scanning helium ion microscope.

109. The method of claim 31, wherein the method can distinguish atoms in the sample having atomic numbers that differ by one.

110. The method of claim 31, wherein the method can distinguish atoms in the sample having masses that differ by one atomic mass unit.