Ion sources, systems and methods

• US 7,786,452 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, Ward, Billy W., Percival, Randall G.
• Primary Examiner(s): Wells; Nikita
• Application Number:
  US11/600,873
• Publication Number:
  US 20090114840A1
• Time in Patent Office: 1,385 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: H01J 2237/0807 Gas field ion sources [GFIS]
• 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

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 having a brightness of 1×

10⁹ A/cm²sr or more at a surface of a sample.

2. The system of claim 1, wherein the ion beam has a brightness of 1×

10¹⁰ A/cm²sr or more at the surface of the sample.

3. The system of claim 1, wherein the ion beam has a brightness of 1×

10¹¹ A/cm²sr or more at the surface of the sample.

4. 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.

5. 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.

6. The system of claim 5, wherein the ion beam current at the surface of the sample is 0.1 fA or more.

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

8. The system of claim 1, further comprising the sample, wherein the gas field ion source comprises an electrically conductive tip, and the surface of the sample is five cm or more from the electrically conductive tip.

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

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

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

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

13. The system of claim 1, further comprising ion optics configured so that at least some ions in the ion beam pass through the ion optics before reaching the sample.

14. The system of claim 13, wherein the ion optics comprise electrodes and an aperture, the aperture being configured to prevent some of the ions in the ion beam from reaching the surface of the sample.

15. 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.

16. The system of claim 1, wherein the gas field ion source includes an electrically conductive tip that comprises a material selected from the group consisting of tungsten, carbon, tantalum, iridium, rhenium, niobium, platinum and molybdenum.

17. The system of claim 1, wherein the gas field ion source comprises a W(111) tip.

18. The system of claim 17, wherein the W(111) tip has a terminal atomic shelf that is a trimer.

19. The system of claim 1, wherein the gas field ion source has a terminal atomic shelf comprising one or more atoms, and 70% or more of the ions in the ion beam that reach a surface of the sample are generated via an interaction of the gas with a single atom of the one or more atoms of the terminal atomic shelf.

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

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

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

23. 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.

24. A system, comprising:

a gas field ion source capable of interacting with a gas to generate an ion beam having a reduced brightness of 5×

10⁸A/m²srV or more at a surface of a sample.

25. A system, comprising:

a gas field ion source capable of interacting with a gas to generate an ion beam having an etendue of 5×

10<sup>−

21</sup> cm²sr or less.

26. The system of claim 25, wherein the etendue is 1×

10<sup>−

22</sup> cm²sr or less.

27. The system of claim 25, wherein the etendue is 1×

10<sup>−

23</sup> cm²sr or less.

28. The system of claim 25, wherein the etendue is 1×

10<sup>−

24</sup> cm²sr or less.

29. The system of claim 25, wherein the ion beam has a reduced brightness at a surface of a sample of 5×

10⁸ A/m²srV or more.

30. The system of claim 25, wherein the ion beam has a brightness at a surface of a sample of 1×

10⁹ A/cm²sr or more at a surface of a sample.

31. The system of claim 25, wherein the ion beam has a spot size with a dimension of 10 nm or less at a surface of a sample.

32. The system of claim 25, wherein the ion beam has an ion beam current at a surface of a sample of one nA or less.

33. The system of claim 31, wherein the ion beam current at a surface of a sample is 0.1 fA or more.

34. The system of claim 25, wherein the ion beam has an energy spread at the surface of the sample of five eV or less.

35. The system of claim 25, further comprising a sample, wherein the gas field ion source comprises an electrically conductive tip, and the surface of the sample is five cm or more from the electrically conductive tip.

36. The system of claim 25, wherein the system is a gas field ion microscope.

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

38. The system of claim 25, wherein the system is a scanning gas field ion microscope.

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

40. The system of claim 39, wherein the ion optics comprise electrodes and an aperture, the aperture being configured to prevent some of the ions in the ion beam from reaching the surface of the sample.

41. The system of claim 25, fun her comprising ion optics configured so that at least some ions in the ion beam pass through the ion optics before reaching the sample.

42. The system of claim 25, fun her 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.

43. The system of claim 25, wherein the gas field ion source includes an electrically conductive tip that comprises a material selected from the group consisting of tungsten, carbon, tantalum, iridium, rhenium, niobium, platinum and molybdenum.

44. The system of claim 43, wherein the W(111) tip has a terminal atomic shelf that is a trimer.

45. The system of claim 25, wherein the gas field ion source comprises a W(111) tip.

46. The system of claim 25, wherein the gas field ion source has a terminal atomic 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 of the gas with a single atom of the one or more atoms of the terminal atomic shelf.

47. The system of claim 25, further comprising a coolant source thermally coupled to the gas field ion source so that during operation of the gas field ion source the temperature of the gas field ion source is 5K or more.

48. The system of claim 25, further comprising a cryogenic refrigerator thermally coupled to the gas field ion source so that during operation of the gas field ion source the temperature of the gas field ion source is 5K or more.

49. The system of claim 25, wherein the ion beam has a convergence half angle of 5 mrad or less at the surface of the sample.

50. The system of claim 25, wherein the gas field ion source comprises an electrically conductive tip having a terminal shelf with 20 atoms or less.

51. A system, comprising:

a gas field ion source capable of interacting with a gas to generate an ion beam having a reduced etendue of 1×

10<sup>−

16</sup> cm²srV or less.

52. The system of claim 51, wherein the reduced etendue is 1×

10<sup>−

17</sup> cm²srV or less.

53. The system of claim 51, wherein the reduced etendue is 1×

10<sup>−

18</sup> cm²srV or less.

54. The system of claim 51, wherein the reduced etendue is 1×

10<sup>−

19</sup> cm²srV or less.

55. The system of claim 51, wherein the ion beam has an etendue of 5×

10<sup>−

21</sup> cm²sr or less.

56. The system of claim 51, wherein the ion beam has a reduced brightness at a surface of a sample of 5×

10⁸ A/m²srV or more.

57. The system of claim 51, wherein the ion beam has a brightness at a surface of a sample of 1×

10⁹ A/cm²sr or more.

58. The system of claim 51, wherein the ion beam has a spot size with a dimension of 10 nm or less at a surface of a sample.

59. The system of claim 58, wherein the ion beam current at a surface of a sample is 0.1 fA or more.

60. The system of claim 51, wherein the ion beam has an ion beam current at a surface of a sample of one nA or less.

61. The system of claim 51, wherein the ion beam has an energy spread at a surface of a sample of five eV or less.

62. The system of claim 51, further comprising a sample, wherein the gas field ion source comprises an electrically conductive tip, and the surface of the sample is five cm or more from the electrically conductive tip.

63. The system of claim 51, wherein the system is a gas field ion microscope.

64. The system of claim 51, wherein the system is a helium ion microscope.

65. The system of claim 51, wherein the system is a scanning gas field ion microscope.

66. The system of claim 51, wherein the system is a scanning helium ion microscope.

67. The system of claim 66, wherein the ion optics comprise electrodes and an aperture, the aperture being configured to prevent some of the ions in the ion beam from reaching the surface of the sample.

68. The system of claim 51, further comprising ion optics configured so that at least some ions in the ion beam pass through the ion optics before reaching the sample.

69. The system of claim 51, 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.

70. The system of claim 51, wherein the gas field ion source includes an electrically conductive tip that comprises a material selected from the group consisting of tungsten, carbon, tantalum, iridium, rhenium, niobium, platinum and molybdenum.

71. The system of claim 70, wherein the W(111) tip has a terminal atomic shelf that is a trimer.

72. The system of claim 51, wherein the gas field ion source comprises a W(111) tip.

73. The system of claim 51, wherein the gas field ion source has a terminal atomic 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 of the gas with a single atom of the one or more atoms of the terminal atomic shelf.

74. The system of claim 51, further comprising a coolant source thermally coupled to the gas field ion source so that during operation of the gas field ion source the temperature of the gas field ion source is 5K or more.

75. The system of claim 51, further comprising a cryogenic refrigerator thermally coupled to the gas field ion source so that during operation of the gas field ion source the temperature of the gas field ion source is 5K or more.

76. The system of claim 51, wherein the ion beam has a convergence half angle of 5 mrad or less at the surface of the sample.

77. The system of claim 51, wherein the gas field ion source comprises an electrically conductive tip having a terminal shelf with 20 atoms or less.