Method of manufacturing CMOS devices by the implantation of N- and P-type cluster ions

• US 20040002202A1
• Filed: 09/20/2002
• Published: 01/01/2004
• Est. Priority Date: 06/26/2002
• Status: Abandoned Application

• Current Assignee: SemEquip, Inc. (3M Company)
• Original Assignee: SemEquip, Inc. (3M Company)
• Inventors: Horsky, Thomas Neil, Jacobson, Dale Conrad, Krull, Wade Allen
• Application Number:
  US10/251,491
• Publication Number:
  US 20040002202A1
• Time in Patent Office: Days
• US Class Current: 438/515
• CPC Class Codes: H01J 2237/31701 Ion implantation
• CPC Class Codes: H01L 21/26513 of electrically active species
• CPC Class Codes: H01L 21/26566 of a cluster, e.g. using a gas cluster ion beam
• CPC Class Codes: H01L 21/2658 of a molecular ion, e.g. decaborane
• CPC Class Codes: H01L 21/425 producing ion implantation
• CPC Class Codes: H01L 21/823814 with a particular manufacturing method of the source or drain structures, e.g. specific source or drain implants or silicided source or drain structures or raised source or drain structures
• CPC Class Codes: H01L 21/823842 gate conductors with different gate conductor materials or different gate conductor implants, e.g. dual gate structures

Abstract

A method of manufacturing a semiconductor device is described, wherein clusters of N- and P-type dopants are implanted to form the transistor structures in CMOS devices. For example, As₄H_x⁺ clusters and either B₁₀H_x⁻ or B₁₀H_x⁺ clusters are used as sources of As and B doping, respectively, during the implants. An ion implantation system is described for the implantation of cluster ions into semiconductor substrates for semiconductor device manufacturing. A method of producing higher-order cluster ions of As, P, and B is presented, and a novel electron-impact ion source is described which favors the formation of cluster ions of both positive and negative charge states. The use of cluster ion implantation, and even more so the implantation of negative cluster ions, can significantly reduce or eliminate wafer charging, thus increasing device yields.

A method of manufacturing a semiconductor device is further described, comprising the steps of: providing a supply of dopant atoms or molecules into an ionization chamber, combining the dopant atoms or molecules into clusters containing a plurality of dopant atoms, ionizing the dopant clusters into dopant cluster ions, extracting and accelerating the dopant cluster ions with an electric field, selecting the desired cluster ion by mass analysis, modifying the final implant energy of the cluster ion through post-analysis ion optics, and implanting the dopant cluster ions into a semiconductor substrate. In general, dopant clusters contain n dopant atoms where n can be 2, 3, 4 or any integer number. This method provides the advantages of increasing the dopant dose rate to n times the implantation current with an equivalent per dopant atom energy of 1/n times the cluster implantation energy. This is an effective method for making shallow transistor junctions, where it is desired to implant with a low energy per dopant atom.

Claims

1. A method of implanting dopant materials into a semiconductor substrate comprising:

generating N-type dopant cluster ions As₄+; and

implanting said N-type As₄+ dopant cluster ions into a first region of said substrate resulting in N-type doping of said substrate.

2. The method as recited in claim 1, wherein said generating step comprises:

providing a source of arsine (AsH₃) gas;

providing a conduit between said source of arsine (AsH₃) gas and an ionization chamber to enable said gaseous arsine (AsH₃) to communicate with said ionization chamber; and

ionizing said arsine (AsH₃) gas in said ionization chamber.

3. The method as recited in claim 2, wherein said ionizing step comprises irradiation within said ionization chamber by one or more electron beams.

4. The method as recited in claim 2, further including the step of controlling the temperature of said ionization chamber to a predetermined value.

5. The method as recited in claim 2, wherein said implanting step includes the step of extracting As₄+ ions from said ionization chamber by an electric field.

6. The method as cited in claim 5, further including the step of mass analyzing the extracted ions by selecting the As₄+ ions.

7. The method as recited in claim 1, further including the step of:

generating P-type dopant cluster ions; and

implanting said P-type dopant cluster ions into said substrate into a second region different than said first region.

8. The method as recited in claim 7, wherein said generating step comprises generating negative decaborane cluster ions (B₁₀H_x⁻

), where x is an integer and 0≦

x≦

14.

96. The method as recited in claim 8, wherein said generating step comprises generating positive decaborane (B₁₀H_x+) cluster ions, where 0≦

x≦

14.

9. A method of implanting dopant materials into a semiconductor substrate comprising:

generating N-type dopant cluster ions As₃⁺; and

implanting said N-type As₃⁺ dopant cluster ions into a first region of said substrate resulting in N-type doping of said substrate.

10. The method as recited in claim 9, wherein said generating step comprises:

providing a source of arsine (AsH₃) gas;

providing a conduit between said source of arsine (AsH₃) gas and an ionization chamber to enable said gaseous arsine (AsH₃) to communicate with said ionization chamber; and

ionizing said arsine (AsH₃) gas in said ionization chamber.

11. The method as recited in claim 10, wherein said ionizing step comprises irradiation within said ionization chamber by one or more electron beams.

12. The method as recited in claim 10, further including the step of controlling the temperature of said ionization chamber to a predetermined value.

13. The method as recited in claim 10, wherein said implanting step includes the step of extracting As₃⁺ ions from said ionization chamber by an electric field.

14. The method as cited in claim 13, further including the step of mass analyzing the extracted ions by selecting the As₃⁺ ions.

15. The method as recited in claim 9, further including the step of:

generating P-type dopant cluster ions; and

implanting said P-type dopant cluster ions into said substrate into a second region different than said first region.

16. The method as recited in claim 15, wherein said generating step comprises generating negative decaborane cluster ions (B₁₀H_x⁻

), where x is an integer and 0≦

x≦

14.

17. A method of implanting dopant materials into a semiconductor substrate comprising:

generating N-type dopant cluster ions As⁴H_x⁺, where x is an integer and 1≦

x≦

6;

implanting said N-type dopant cluster ions into a first region of said substrate resulting in N-type doping of said substrate.

18. The method as recited in claim 17, wherein said generating step comprises:

providing a source of arsine (AsH₃) gas;

providing a conduit between said source of arsine (AsH₃) gas and an ionization chamber to enable said gaseous arsine (AsH₃) to communicate with said ionization chamber; and

ionizing said arsine (AsH₃) gas in said ionization chamber.

19. The method as recited in claim 18, wherein said ionizing step comprises irradiation within said ionization chamber by one or more electron beams.

20. The method as recited in claim 18, further including the step of controlling the temperature of said ionization chamber to a predetermined value.

21. The method as recited in claim 18, wherein said implanting step includes the step of extracting said dopant cluster ions from said ionization chamber by an electric field.

22. The method as cited in claim 21, further including the step of mass analyzing the extracted ions by selecting said dopant cluster ions.

23. The method as recited in claim 17, further including the step of:

generating P-type dopant cluster ions; and

implanting said P-type dopant cluster ions into said substrate into a second region different than said first region.

24. The method as recited in claim 23, wherein said generating step comprises generating negative decaborane cluster ions (B₁₀H_x⁻

), where x is an integer and 0≦

x≦

14.

31. The method as recited in claim 23, further including the step of:

generating P-type dopant cluster ions, and

implanting said P-type dopant cluster ions into said substrate into a second region different than said first region.

32. The method as recited in claim 31, wherein said generating step comprises generating negative decaborane cluster ion (B₁₀H_x⁻

), where x is an integer and 0≦

x≦

14.

97. The method as recited in claim 17, wherein said generating step comprises generating positive decaborane (B₁₀H_x+) cluster ions, where 0≦

x≦

14.

25. A method of implanting dopant materials into a semiconductor substrate comprising:

generating N-type dopant cluster ions As₃ Hx+, where x is an integer and 1≦

x≦

5; and

implanting said N-type As₃ Hx+, cluster ions into a first region of said substrate resulting in N-type doping of said substrate.

26. The method as recited in claim 25, wherein said generating step comprises:

providing a source of arsine (AsH₃) gas;

providing a conduit between said source of arsine (AsH₃) gas and an ionization chamber to enable said gaseous arsine (AsH₃) to communicate with said ionization chamber; and

ionizing said arsine (AsH₃) gas in said ionization chamber.

27. The method as recited in claim 26, wherein said ionizing step comprises irradiation within said ionization chamber by one or more electron beams.

28. The method as recited in claim 26, further including the step of controlling the temperature of said ionization chamber to a predetermined value.

29. The method as recited in claim 26, wherein said implanting step includes the step of extracting said dopant cluster ions from said ionization chamber by an electric field.

30. The method as cited in claim 29, further including the step of mass analyzing the extracted ions and selecting the As₃H_x+ species.

98. The method as recited in claim 26, wherein said generating step comprises generating positive decaborane (B₁₀H_x+) cluster ions, where 0≦

x≦

14.

106. The method as recited in claim 98, wherein said generating step comprises generating positive decaborane (B₁₀H_x+) cluster ions, where 0≦

x≦

14.

33. A method of implanting dopant materials into a semiconductor substrate comprising:

generating N-type dopant cluster ions P₄+; and

implanting said N-type P₄+ dopant cluster ions into a first region of said substrate resulting in N-type doping of said substrate.

34. The method as recited in claim 33, wherein said generating step comprises:

providing a source of phosphine (PH₃) gas;

providing a conduit between said source of phosphine (PH₃) gas and an ionization chamber to enable said gaseous phosphine (PH₃) to communicate with said ionization chamber; and

ionizing said phosphine (PH₃) gas in said ionization chamber.

35. The method as recited in claim 34, wherein said ionizing step comprises irradiation within said ionization chamber by one or more electron beams.

36. The method as recited in claim 34, further including the step of controlling the temperature of said ionization chamber to a predetermined value.

37. The method as recited in claim 34, wherein said implanting step includes the step of extracting P₄+ ions from said ionization chamber by an electric field.

38. The method as cited in claim 37, further including the step of mass analyzing the extracted ions by selecting the P₄+ species.

39. The method as recited in claim 33, further including the step of:

generating P-type dopant cluster ions; and

implanting said P-type dopant cluster ions into said substrate into a second region different than said first region.

40. The method as recited in claim 39, wherein said generating step comprises generating negative decaborane cluster ions (B₁₀H_x⁻

), where x is an integer and 0≦

x≦

14.

99. The method as recited in claim 35, wherein said generating step comprises generating positive decaborane (B₁₀H_x+) cluster ions, where 0≦

x≦

14.

41. A method of implanting dopant materials into a semiconductor substrate comprising:

generating N-type dopant cluster ions P₃+; and

implanting said N-type P₃+ dopant cluster ions into a first region of said substrate resulting in N-type doping of said substrate.

42. The method as recited in claim 41, wherein said generating step comprises:

providing a source of phosphine (PH₃) gas;

providing a conduit between said source of phospine (PH₃) gas and an ionization chamber to enable said gaseous phosphine (PH₃) to communicate with said ionization chamber; and

ionizing said phosphine (PH₃) gas in said ionization chamber.

43. The method as recited in claim 42, wherein said ionizing step comprises irradiation within said ionization chamber by one or more electron beams.

44. The method as recited in claim 47, further including the step of controlling the temperature of said ionization chamber to a predetermined value.

45. The method as recited in claim 42, wherein said implanting step includes the step of extracting P₃+ ions from said ionization chamber.

47. The method as recited in claim 42 further including the step of:

generating P-type dopant cluster ions; and

implanting said P-type dopant cluster ions into said substrate into a second region different than said first region.

48. The method as recited in claim 47, wherein said generating step comprises generating negative decaborane cluster ions (B₁₀H_x⁻

), where x is an integer and 0≦

x≦

14.

100. The method as recited in claim 44, wherein said generating step comprises generating positive decaborane (B₁₀H_x+) cluster ions, where 0≦

x≦

14.

49. A method of implanting dopant materials into a semiconductor substrate comprising:

generating N-type dopant cluster ions P₂+; and

implanting said N-type P₂+ dopant cluster ions into a first region of said substrate resulting in N-type doping of said substrate.

46. The method as cited in claim 50, further including the step of mass analyzing the extracted ions by selecting the P₃+ species.

50. The method as recited in claim 49, wherein said generating step comprises:

providing a source of phosphine (PH₃) gas;

providing a conduit between said source of phosphine (PH₃) gas and an ionization chamber to enable said gaseous phosphine (PH₃) to communicate with said ionization chamber; and

ionizing said phosphine (PH₃) gas in said ionization chamber.

51. The method as recited in claim 50, wherein said ionizing step comprises irradiation within said ionization chamber by one or more electron beams.

52. The method as recited in claim 50, further including the step of controlling the temperature of said ionization chamber to a predetermined value.

53. The method as recited in claim 50, wherein said implanting step includes the step of extracting P₂+ ions from said ionization chamber by an electric field.

54. The method as recited in claim 50, further including the step of mass analyzing the extracted ions by selecting the P₂+ species.

55. The method as recited in claim 50, further including the step of:

generating P-type dopant cluster ions; and

implanting said P-type dopant cluster ions into said substrate into a second region different than said first region.

56. The method as recited in claim 55, wherein said generating step comprises generating negative decaborane cluster ion (B₁₀H_x⁻

), where x is an integer and 0≦

x≦

14.

101. The method as recited in claim 53, wherein said generating step comprises generating positive decaborane (B₁₀H_x+) cluster ions, where 0≦

x≦

14.

57. A method of implanting dopant materials into a semiconductor substrate comprising:

generating N-type cluster dopant ions P₄H_x+, where x is an integer and 1≦

x≦

6; and

implanting said N-type P₄H_x+ dopant cluster ions into a first region of said substrate resulting in N-type doping of said substrate.

58. The method as recited in claim 57, wherein said generating step comprises:

providing a source of phosphine (PH₃) gas;

providing a conduit between said source of phosphine (PH₃) gas and an ionization chamber to enable said gaseous phosphine (PH₃) to communicate with said ionization chamber; and

ionizing said phosphine (PH₃) gas in said ionization chamber.

59. The method as recited in claim 58, wherein said ionizing step comprises irradiation within said ionization chamber by one or more electron beams.

60. The method as recited in claim 58, further including the step of controlling the temperature of said ionization chamber to a predetermined value.

61. The method as recited in claim 58, wherein said implanting step includes the step of extracting P₄H_x+ ions from said ionization chamber by an electric field, where x is an integer and 1≦

x≦

6.

62. The method as cited in claim 61, further including the step of mass analyzing the extracted ions by selecting said dopant cluster ions.

63. The method as recited in claim 57, further including the step of:

generating P-type dopant cluster ions; and

implanting said P-type dopant cluster ions into said substrate into a second region different than said first region.

64. The method as recited in claim 63, wherein said generating step comprises generating negative decaborane cluster ions (B₁₀H_x⁻

), where x is an integer and 0≦

x≦

14.

102. The method as recited in claim 62, wherein said generating step comprises generating positive decaborane (B₁₀H_x+) cluster ions, where 0≦

x≦

14.

65. A method of implanting dopant materials into a semiconductor substrate comprising:

generating N-type cluster dopant ions P₃H_x+, where x is an integer and 1≦

x≦

5; and

implanting said N-type P₃H_x+ dopant cluster ions into a first region of said substrate resulting in N-type doping of said substrate.

66. The method as recited in claim 65, wherein said generating step comprises:

providing a source of phosphine (PH₃) gas;

providing a conduit between said source of phosphine (PH₃) gas and an ionization chamber to enable said gaseous phosphine (PH₃) to communicate with said ionization chamber; and

ionizing said phosphine (PH₃) gas in said ionization chamber.

67. The method as recited in claim 66, wherein said ionizing step comprises irradiation within said ionization chamber by one or more electron beams.

68. The method as recited in claim 66, further including the step of controlling the temperature of said ionization chamber to a predetermined value.

69. The method as recited in claim 66, wherein said implanting step includes the step of extracting said dopant cluster ions from said ionization chamber by an electric field.

70. The method as cited in claim 66, further including the step of mass analyzing the extracted ions and selecting said dopant cluster ions.

71. The method as recited in claim 65, further including the step of:

generating P-type dopant cluster ions; and

implanting said P-type dopant cluster ions into said substrate into a second region different than said first region.

72. The method as recited in claim 71, wherein said generating step comprises generating negative decaborane cluster ions (B₁₀H_x⁻

), where x is an integer and 0≦

x≦

14.

103. The method as recited in claim 71, wherein said generating step comprises generating positive decaborane (B₁₀H_x+) cluster ions, where 0≦

x≦

14.

73. A method of implanting dopant materials into a semiconductor substrate comprising:

generating an N-type cluster dopant ions P₂H_x+, where x is an integer and 1≦

x≦

4 and

implanting said N-type P₂H_x+, dopant cluster ions into a first region of said substrate resulting in N-type doping of said substrate.

74. The method as recited in claim 73, wherein said generating step comprises:

providing a source of phosphine (PH₃) gas;

providing a conduit between said source of phosphine (PH₃) gas and said ionization chamber to enable said gaseous phosphine (PH₃) to communicate with said ionization chamber; and

ionizing said phosphine (PH₃) gas in said ionization chamber.

75. The method as recited in claim 73, wherein said ionizing step comprises irradiation within said ionization chamber by one or more electron beams.

76. The method as recited in claim 73, further including the step of controlling the temperature of said ionization chamber to a predetermined value.

77. The method as recited in claim 73, wherein said implanting step includes the step of extracting said dopant ions from said ionization chamber by an electric field.

78. The method as cited in claim 77, further including the step of mass analyzing the extracted cluster ions and selecting the P₂H_x+ species, where x is an integer and 1≦

x≦

4.

79. The method as recited in claim 73, further including the step of:

generating P-type dopant cluster ions; and

implanting said P-type dopant cluster ions into said substrate into a second region different than said first region.

80. The method as recited in claim 79, wherein said generating step comprises generating negative decaborane cluster ions (B₁₀H_x⁻

), where x is an integer and 0≦

x≦

14.

104. The method as recited in claim 80, wherein said generating step comprises generating positive decaborane (B₁₀H_x+) cluster ions, where 0≦

x≦

14.

81. A method of implanting a cluster ion dopant material into a semiconductor substrate comprising the steps of:

generating a dopant ion cluster, B_nH_x+, where n and x are integers and 2≦

n≦

9 and 0≦

x≦

14; and

implanting said dopant ion cluster into a first region of said substrate.

82. The method as recited in claim 81, wherein said generating step comprises:

providing a source of diborone (B₂H₆) gas;

providing a conduit between said source of diborone (B₂H₆) gas and an ionization chamber to enable said diborone (B₂H₆) gas to communicate with said ionization chamber; and

ionizing said diborone (B₂H₆) gas in said ionization chamber.

83. The method as recited in claim 82, wherein said ionizing step comprises irradiation within said ionization chamber by one or more electron beams.

84. The method as recited in claim 82, further including the step of controlling the temperature of said ionization chamber to a predetermined value.

85. The method as recited in claim 82, wherein said implanting step includes the step of extracting said dopant cluster ions from said ionization chamber by an electric field

87. The method as recited in claim 81, further including the step of:

generating P-type dopant cluster ions; and

implanting said P-type dopant cluster ions into said substrate into a second region different than said first region.

88. The method as recited in claim 87, wherein said generating step comprises generating negative decaborane cluster ions (B₁₀H_x⁻

) where x is an integer and 0≦

x≦

14.

90. The method as recited in claim 88, wherein said generating step comprises:

providing a source of decaborane (B₁₀H₁₄) vapor;

providing a conduit between said source of decaborane (B₁₀H₁₄) vapor and an ionization chamber to enable said decaborane (B₁₀H₁₄) vapor to communicate with said ionization chamber; and

ionizing said decaborane (B₁₀H₁₄) vapor in said ionization chamber.

91. The method as recited in claim 90, wherein said ionizing step comprises irradiation within said ionization chamber by one or more electron beams.

92. The method as recited in claim 90, wherein further including the step of controlling the temperature of said ionization chamber to a predetermined value.

93. The method as recited in claim 90, wherein said implanting step includes the step of extracting negative decaborane cluster ions B₁₀H_x⁻

from said ionization chamber, where x is an integer and 0≦

x≦

14.

94. The method as recited in claim 93, further including the step of mass analyzing negative decaborane cluster ions B₁₀H_x⁻

, species where x equals 0≦

x≦

14.

117. The method as recited in claim 81, wherein said generating step comprises:

providing a source of decaborane (B₁₀H₁₄) vapor;

providing a conduit between said source of decaborane (B₁₀H₁₄) vapor and an ionization chamber to enable said gas to communicate with said ionization chamber; and

ionizing said decaborane (B₁₀H₁₄) vapor in said ionization chamber.

89. A method of implanting dopant materials into a semiconductor substrate comprising:

generating P-type negative decaborane cluster dopant ions (B₁₀H_x⁻

), where x is an integer and 0≦

x≦

14; and

implanting said negative decaborane (B₁₀H_x⁻

) dopant cluster ions into a first region on said substrate resulting in P-type doping of said substrate.

105. The method as recited in claim 89, wherein said generating step comprises generating positive decaborane (B₁₀H_x+) cluster ions, where 0≦

x≦

14.

95. A semiconductor device comprising:

a substrate having one or more N-type regions formed from an N-type material; and

a P-type dopant implanted into said N-type region, said P-type dopant formed by implantation of negative decaborane cluster ions B₁₀H_x⁻

into said p-type region, where x is an integer and 0≦

x≦

14.

86. The method as cited in claim 95, further including the step of mass analyzing the extracted ions by selecting said dopant cluster ions.

107. A method of forming cluster ions comprising:

providing a supply of dopant atoms into an ionization chamber; and

combining the dopant atoms into clusters containing a plurality of dopant atoms.

108. The method as recited in claim 107 further comprising:

ionizing the dopant clusters into dopant cluster ions;

extracting said dopant cluster ions; and

implanting said dopant cluster ions into a substrate.

109. The method as recited in claim 107, wherein said supply of dopant atoms is in the form of A_sH₃.

110. The method as recited in claim 109, wherein said supply of dopant atoms is in the form of PH₃.

111. The method as recited in claim 109, wherein said supply of dopant atoms is in the form of B₂H₆.

112. A method of forming cluster ions comprising:

providing a supply of dopant molecules into an ionization chamber; and

combining the dopant molecules into clusters containing a plurality of dopant molecules.

113. The method as recited in claim 112 further comprising:

ionizing the dopant clusters into dopant cluster ions;

extracting said dopant cluster ions; and

implanting said dopant cluster ions into a substrate.

114. The method as recited in claim 113, wherein said supply of dopant atoms is in the form of A_sH₃.

115. The method as recited in claim 113, wherein said supply of dopant atoms is in the form of PH₃.

116. The method as recited in claim 113, wherein said supply of dopant atoms is in the form of B₂H₆.