Atomic layer deposition and conversion

• US 20030207593A1
• Filed: 05/02/2002
• Published: 11/06/2003
• Est. Priority Date: 05/02/2002
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Derderian, Garo J., Sandhu, Gurtej Singh
• Granted Patent: US 7,589,029 B2
• Time in Patent Office: Days
• US Class Current: 438/778
• CPC Class Codes: C23C 16/452 by activating reactive gas streams before their introduction into the reaction chamber, e.g. by ionisation or addition of reactive species
• CPC Class Codes: C23C 16/45531 specially adapted for making ternary or higher compositions
• CPC Class Codes: C23C 16/45536 Use of plasma, radiation or electromagnetic fields
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01L 21/0214 the material being a silicon oxynitride, e.g. SiON or SiON:H
• CPC Class Codes: H01L 21/0215 the material containing tantalum, e.g. TaSiOx
• CPC Class Codes: H01L 21/02153 the material containing titanium, e.g. TiSiOx
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/02183 the material containing tantalum, e.g. Ta2O5
• CPC Class Codes: H01L 21/02186 the material containing titanium, e.g. TiO2
• CPC Class Codes: H01L 21/02244 of a metallic layer
• CPC Class Codes: H01L 21/02249 formation by combined oxidation and nitridation performed simultaneously
• CPC Class Codes: H01L 21/02255 formation by thermal treatment H01L21/02252 takes precedence; after treatment of an insulating film H01L21/3105 and subgroups
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/31604 Deposition from a gas or vapour H01L21/31691, H01L21/31695 take precedence
• CPC Class Codes: H01L 21/31616 Deposition of Al2O3
• CPC Class Codes: H01L 21/31683 of metallic layers, e.g. Al deposited on the body, e.g. formation of multi-layer insulating structures

Abstract

A method for growing films for use in integrated circuits using atomic layer deposition and a subsequent converting step is described. In an embodiment, the subsequent converting step includes oxidizing a metal atomic layer to form a metal oxide layer. The atomic layer deposition and oxidation step are then repeated to produce a metal oxide layer having sufficient thickness for use as a metal oxide layer in an integrated circuit. The subsequent converting step, in an embodiment, includes converting the atomic deposition layer by exposing it to one of nitrogen to form a nitride layer, carbon to form a carbide layer, boron to form a boride layer, and fluorine to form a fluoride layer. Systems and devices for performing the method, semiconductor devices so produced, and machine readable media containing the method are also described.

Claims

1. A method of forming a thin film on a substrate, comprising:

atomic layer depositing a first element as a thin film on the substrate; and

reacting the first element thin film to form a compound thin film including the first element.

2. The method according to claim 1, wherein atomic layer depositing includes:

flowing a first element-containing gas into a reaction chamber containing the substrate;

flowing a second gas into the reaction chamber; and

reacting the first gas with the second gas adjacent the substrate to deposit the thin layer on the substrate.

3. The method according to claim 1, wherein atomic layer depositing includes:

flowing a first element-containing gas into a reaction chamber containing the substrate; and

chemisorping the first element onto the substrate to form an atomic layer.

4. The method of claim 3, wherein the atomic layer depositing steps are repeated until the metal layer has a desired thickness.

5. A method of forming a metal oxide film on a substrate, comprising:

atomic layer depositing a metal on the substrate; and

oxidizing the deposited metal to form a metal oxide.

6. The method according to claim 5, wherein atomic layer depositing includes:

flowing a first, metal-containing gas into a reaction chamber containing the substrate;

flowing a second gas into the reaction chamber; and

reacting the first gas with the second gas adjacent the substrate to deposit a metal layer on the substrate.

7. The method of claim 6, further comprising flowing an inert purge gas into the chamber in between flowing the first gas and the second gas.

8. The method of claim 5, wherein atomic layer depositing includes:

flowing a metal-containing gas into a reaction chamber containing the substrate; and

chemisorping the metal onto the substrate to form a metal atomic layer.

9. The method of claim 8, wherein the atomic layer depositing steps are repeated until the metal layer has a desired thickness.

10. The method of claim 8, wherein flowing the first gas includes flowing a gas containing titanium into the reaction chamber.

11. The method of claim 8, wherein flowing the first gas includes flowing a gas containing tantalum into the reaction chamber.

12. The method of claim 8, wherein flowing the first gas includes flowing a gas containing aluminum into the reaction chamber.

13. The method of claim 5, wherein the process steps are performed in the listed order.

14. A method of forming a metal oxide layer on a substrate, comprising:

flowing a first, metal-containing gas into a reaction chamber containing the substrate;

flowing a second, activated hydrogen gas into the reaction chamber;

reacting the first gas with the second gas adjacent the substrate to deposit a metal layer on the substrate; and

oxidizing the metal layer.

15. The method of claim 14, wherein, if necessary, the process steps are repeated in the recited order until the oxidized metal layer has a desired thickness.

16. The method of claim 14, wherein the steps are performed in the listed order.

17. The method of claim 14, wherein flowing the first gas includes flowing a gas containing titanium into the reaction chamber.

18. The method of claim 14, wherein flowing the first gas includes flowing a gas containing tantalum into the reaction chamber.

19. The method of claim 14, wherein flowing the first gas includes flowing a gas containing aluminum into the reaction chamber.

20. The method of claim 14, further comprising flowing an inert purge gas into the chamber in between flowing the precursor gas and the reactant gas.

21. A method of forming an IC capacitor, comprising:

forming a bottom electrode on a substrate;

flowing a first gas into a chamber containing the substrate;

flowing a second gas into the chamber;

reacting the first and second gases to form a monolayer of metal on the bottom electrode;

oxidizing the monolayer of metal; and

forming a top electrode on the oxidized metal.

22. The method of claim 21, wherein flowing the first gas includes flowing a gas containing titanium into the chamber.

23. The method of claim 21, wherein flowing the first gas includes flowing a gas containing tantalum into the chamber.

24. The method of claim 21, wherein flowing the first gas includes flowing a gas containing aluminum into the chamber.

25. The method of claim 21, wherein the process steps are performed in the listed order.

26. The method of claim 21, wherein flowing the second gas includes flowing activated hydrogen into the chamber

27. A method of forming a transistor, comprising:

forming a source region on a substrate;

forming a drain region on the substrate;

flowing a first gas into a chamber containing the substrate;

flowing a second gas into the chamber;

reacting the first and second gases to form a monolayer of metal on the substrate;

oxidizing the monolayer of metal to form a gate oxide; and

forming gate on the gate oxide.

28. The method of claim 27, wherein flowing the first gas includes flowing a gas containing titanium into the chamber.

29. The method of claim 27, wherein flowing the first gas includes flowing a gas containing tantalum into the chamber.

30. The method of claim 27, wherein flowing the first gas includes flowing a gas containing aluminum into the chamber.

31. The method of claim 27, wherein the process steps are performed in the listed order.

32. The method of claim 27, wherein flowing the second gas includes flowing activated hydrogen into the chamber.

33. The method of claim 27, wherein one of the first gas and the second gas includes a metal component that forms the metal monolayer.

34. A method of forming a metal oxide layer in an IC, comprising:

forming a first layer of precursor molecules by chemisorption on a top layer of a substrate;

forming a second layer of molecules on the first layer;

reacting the second layer with the first layer to form a metal layer; and

oxidizing the metal layer.

35. The method of claim 34, wherein forming the first layer includes flowing a gas containing titanium into a chamber containing the substrate.

36. The method of claim 34, wherein forming the first layer includes flowing a gas containing tantalum into a chamber containing the substrate.

37. The method of claim 34, wherein forming the first layer includes flowing a gas containing aluminum into a chamber containing the substrate.

38. The method of claim 34, wherein forming the second layer includes flowing activated hydrogen into a chamber containing the substrate.

39. The method of claim 34, wherein oxidizing includes flowing one of O₂, O₃, N₂O, and activated oxygen into a chamber containing the substrate.

40. A method of forming an Al₂O₃ layer in an IC, comprising:

flowing trimethylaluminum onto a substrate;

flowing activated hydrogen onto the trimethylaluminum on the substrate;

reacting the trimethylaluminum and the activated hydrogen to form an aluminum layer on the substrate; and

oxidizing the aluminum layer to form Al₂O₃ layer

41. The method of claim 40, wherein reacting includes purging by-product gas away from the substrate.

42. The method of claim 41, wherein purging by-product gas includes purging CH₄ away from the substrate.

43. The method of claim 41, wherein oxidizing includes flowing at least one of O₂, O₃, N₂O, and activated oxygen onto the aluminum layer.

44. A method of forming an Ta₂O₅ layer in an IC, comprising:

flowing TaCl₅ onto a substrate;

flowing activated hydrogen onto the TaCl₅ on the substrate;

reacting the TaCl₅ and the activated hydrogen to form a tantalum layer on the substrate; and

oxidizing the tantalum layer to form a Ta₂O₅ layer.

45. The method of claim 44, wherein reacting includes purging by-product gas away from the substrate.

46. The method of claim 45, wherein purging by-product gas includes purging HCl away from the substrate.

47. The method of claim 45, wherein oxidizing includes flowing at least one of O₂, O₃, N₂O, and activated oxygen onto the aluminum layer.

48. A method of forming an TiO_x layer in an IC, comprising:

flowing TiCl₄ onto a substrate;

flowing activated hydrogen onto the TiCl₄ on the substrate;

reacting the TiCl₄ and the activated hydrogen to form a titanium layer on the substrate; and

oxidizing the titanium layer to form a TiO_x layer.

49. The method of claim 48, wherein reacting includes purging by-product gas away from the substrate.

50. The method of claim 49, wherein purging by-product gas includes purging HCl away from the substrate.

51. The method of claim 48, wherein oxidizing includes flowing at least one of O₂, O₃, N₂O, and activated oxygen onto the aluminum layer.

52. A method of forming a nitride film in a IC, comprising:

atomic layer depositing a first material on a substrate; and

exposing the first material to a nitride to form a nitride layer including the first material.

53. The method of claim 52, wherein atomic layer depositing includes:

flowing a first material-containing gas into a reaction chamber containing the substrate;

flowing a second gas into the reaction chamber; and

reacting the first gas with the second gas adjacent the substrate to deposit the first material on the substrate.

54. The method of claim 53, wherein the first material is a metal.

55. The method of claim 54, wherein the metal is at least one of titanium, tungsten, and tantalum.

56. A method of forming a boride film in a IC, comprising:

atomic layer depositing a first material on a substrate; and

exposing the first material to a boride to form a boride layer including the first material.

57. The method of claim 56, wherein atomic layer depositing includes:

flowing a first material-containing gas into a reaction chamber containing the substrate;

flowing a second gas into the reaction chamber; and

reacting the first gas with the second gas adjacent the substrate to deposit the first material on the substrate.

58. The method of claim 57, wherein the first material includes a metal.

59. A method of forming a carbide layer in a IC, comprising:

atomic layer depositing a first material on a substrate; and

exposing the first material to a carbide to form a carbide layer including the first material.

60. The method of claim 59, wherein atomic layer depositing includes:

flowing a first material-containing gas into a reaction chamber containing the substrate;

flowing a second gas into the reaction chamber; and

reacting the first gas with the second gas adjacent the substrate to deposit the first material on the substrate.

61. The method of claim 60, wherein the first material includes a metal.

62. A method of forming a fluoride film in a IC, comprising:

atomic layer depositing a first material on a substrate; and

exposing the first material to a fluoride to form a fluoride layer including the first material.

63. The method of claim 62, wherein atomic layer depositing includes:

flowing a first material-containing gas into a reaction chamber containing the substrate;

flowing a second gas into the reaction chamber; and

reacting the first gas with the second gas adjacent the substrate to deposit the first material on the substrate.

64. The method of claim 63, wherein the first material includes a metal.

65. A method of forming a thin film on a substrate, comprising:

atomic layer depositing a first element as a thin film on the substrate;

reacting the first element thin film to form a compound thin film including the first element;

atomic layer depositing a second element as a thin film on the compound film;

reacting the second element thin film to form a further compound thin film including the second element.

66. The method according to claim 65, wherein atomic layer depositing includes:

flowing a first element-containing gas into a reaction chamber containing the substrate;

flowing a second gas into the reaction chamber; and

reacting the first gas with the second gas adjacent the substrate to deposit the thin film containing the first element on the substrate.

67. The method according to claim 65, wherein atomic layer depositing includes:

flowing a first element-containing gas into a reaction chamber containing the substrate; and

chemisorping the first element onto the substrate to form an atomic layer.

68. The method of claim 67, wherein the atomic layer depositing steps are repeated until thin layer has a desired thickness.

69. The method of claim 65, wherein atomic layer depositing a first element includes depositing titanium.

70. The method of claim 69, wherein atomic layer depositing the second element includes deposing silicon.

71. The method of claim 70, wherein reacting the first element thin film includes oxidizing the titanium to form titanium oxide.

72. The method of claim 71, wherein reacting the second element thin film includes oxidizing the silicon to form silicon oxide.

73. The method of claim 71, wherein reacting the second element thin film includes nitridizing the silicon to form silicon nitride.

74. The method of claim 65, further comprising:

atomic layer depositing the first element as a thin film on the further compound film;

reacting the first element thin film to form a compound thin film including the first element;

atomic layer depositing a second element as a thin film on the compound film;

reacting the second element thin film to form a further compound thin film including the second element.

75. The method of claim 74, wherein the steps are repeated until the film that includes the reacted first element and the reacted second element has a desired thickness.

76. A semiconductor device, comprising:

a substrate; and

an atomic layer deposition first layer deposited on the substrate, wherein the first layer is deposited sequentially pulsing a precursor gas and a reactant into a reaction chamber, and wherein the precursor gas and reactant react to deposit the first layer on the substrate, and wherein the first layer is converted to a second layer by a converting gas.

77. The semiconductor device according to claim 76, wherein the first layer is an atomic layer deposition metal layer.

78. The semiconductor device according to claim 77, wherein the second layer is a metal oxide.

79. The semiconductor device according to claim 78, wherein the first and second metal layers include at least one of titanium, tantalum and aluminum.

80. A memory device in an integrated circuit, comprising:

an memory cell; and

access circuit operably connected to the memory cell; and

wherein at least one of the memory cell and the access circuit includes;

a substrate; and

an atomic layer deposition first layer deposited on the substrate, wherein the first layer is essentially devoid of contaminants, the first layer is deposited by sequentially pulsing a precursor gas and a reactant into a reaction chamber, and wherein the precursor gas and reactant react predominately adjacent the substrate to deposit the first layer on the substrate, the first layer being part of the memory device, and wherein first layer is converted to a second layer by a converting gas.

81. The memory device according to claim 80, wherein the second layer is a gate oxide of a transistor in the memory device.

82. The memory device according to claim 80, wherein the second layer is a dielectric in a capacitor in the memory device.

83. A logic device in an integrated circuit, comprising:

a logic circuit;

input/output circuit connected to the logic circuit; and

wherein at least one of the logic circuit and the input/output circuit includes;

a substrate; and

a first layer deposited on the substrate, wherein the first layer is essentially devoid of contaminants, the first layer is deposited by sequentially pulsing a precursor gas and a reactant into a reaction chamber, and wherein the precursor gas and reactant react predominately adjacent the substrate to deposit the first layer on the substrate, the first layer being part of a logic device, and wherein the first layer is converted to a second layer by a converting gas.

84. The logic device according to claim 83, wherein the first layer is one of a gate oxide in a transistor in the logic device.

85. The logic device according to claim 84, wherein the first layer is one of a dielectric in a capacitor of the logic device.

86. A semiconductor device, comprising:

a substrate;

a first layer of a film deposited on the substrate, wherein the first layer is deposited by injecting a pulse of precursor gas into a chamber containing the substrate and injecting a pulse of reactant gas into the chamber, wherein the precursor and the reactant react to deposit the first layer on the substrate, wherein the first layer is converted to a second layer by a converting gas; and

a third layer of the film deposited on the second layer of the film, wherein the second layer is deposited by injecting a pulse of precursor gas into a chamber containing the substrate and injecting a pulse of reactant gas into the chamber, wherein the precursor and the reactant react to deposit the third layer on the second layer, wherein the third layer is converted to a fourth layer by a converting gas, still further wherein the pulses of precursor gas and reactant gas are separate.

87. The semiconductor device according to claim 86, wherein the second and fourth layers are the same material.

88. The semiconductor device according to claim 87, wherein the second and fourth layers are include a metal oxide.

89. The semiconductor device according to claim 88, wherein the first and third layers are ALD metal layers

90. The semiconductor device according to claim 86, wherein the pulse the precursor gas and the pulse of the reactant gas are separated by a time period, wherein the time period allows the precursor gas to settle adjacent the surface of the substrate.

91. A deposition device for forming films on substrates, comprising:

a reaction chamber;

a source of precursor gas;

a source of reactant gas;

a source of converting gas;

a mount for a substrate in the chamber; and

a controller for sequentially pulsing the precursor gas, the reactant gas and converting gas into the chamber, the precursor gas being first pulsed into the chamber so that the precursor gas is adjacent a surface of the substrate, the reactant gas being pulsed into the chamber to react with the precursor gas to deposit a film on the surface of the substrate, and the converting gas being pulsed in the chamber to convert the film to a different chemical structure.

92. The deposition device according to claim 91, wherein the controller discretely pulses the precursor gas, the reactant gas, and the converting gas into the chamber.

93. The deposition device according to claim 91, wherein the converting gas is an oxidizer, and the precursor gas includes a metal.

94. A machine readable medium having instructions stored thereon, comprising:

first instructions for causing a deposition reactor to initiate depositing a film on a substrate by injecting a pulse of precursor gas into a chamber containing the substrate;

second instructions for causing the reactor to inject a pulse of reactant gas into the chamber after the pulse of precursor gas has been injected into the chamber; and

third instructions for causing the reactor to inject a converting gas into the chamber after the pulse of reactant gas had been injected into the chamber.

95. The machine readable medium according to claim 94, further comprising fourth instructions for causing the reactor to continue sequentially injecting pulses of precursor gas, reactant gas and converting gas until the deposited film has a select thickness.

96. The machine readable medium according to claim 94, wherein the first instructions for causing a reactor to initiate depositing a film further comprise instructions for ending the pulse of precursor gas prior to proceeding to the second instructions.

97. The machine readable medium according to claim 94, wherein the second instructions include a delay during which neither the precursor gas nor the reactant gas are injected into the chamber.

98. The machine readable medium according to claim 94, further comprising fourth instructions for holding the chamber at a constant pressure.

99. The machine readable medium according to claim 94, wherein the first instructions cause the reactor to inject a precursor gas having a metal constituent that will be deposited on the substrate.

100. The machine readable medium according to claim 99, wherein the third instructions include instructions causing the reactor to inject an oxidizing gas that oxidizes the metal deposited on the substrate by atomic layer deposition.

101. A IC film deposition system, comprising:

a deposition reactor including a chamber storing a substrate;

a control system in communication with the reactor; and

a machine readable medium in communication with the control system, wherein the machine readable medium has;

first instructions for causing the reactor to initiate depositing a film on the substrate by injecting a pulse of precursor gas into the chamber,

second instructions for causing the reactor to inject a pulse of reactant gas into the chamber after the pulse of precursor gas is injected into the chamber to cause a film to be deposited on the substrate, and

third instructions for causing the reactor to inject a pulse of converting gas into the chamber to convert the film.

102. The system of claim 101, further comprising fourth instructions for causing the reactor to continue sequentially injecting pulses of precursor gas, reactant gas, and converting gas until the deposited film has a select thickness.

103. The system of claim 102, wherein the third instructions include instructions to delay injection of pulses of precursor gas until after the pulse of converting gas ends.

104. The system of claim 103, wherein the first instructions include instructions to delay injection of pulses of precursor gas until after a time delay elapses after the end of the pulse of converting gas.

105. The system of claim 104, wherein the second instructions include instructions to delay injection of pulses of reactant gas until after a time delay elapses after the end of the pulse of precursor gas.

106. The system of claim 102, wherein the control system is physically associated with the reactor.

107. The system of claim 106, wherein the machine readable medium is physically associated with the control system.

108. The system of claim 102, wherein the first instructions cause the reactor to inject a precursor gas having a metal constituent to be deposited on the substrate.

109. The system of claim 108, wherein the third instructions cause the reactor to inject an oxidizing gas to convert the metal on the substrate to a metal oxide layer.

110. A reactor for forming films on substrates, comprising:

a chamber;

a first gas source connected to the chamber;

a second gas source connected to the chamber;

a third gas source connected to the chamber;

a mount for a substrate in the chamber; and

a controller sequentially activating the first gas source and the second gas source such that the first gas is in the chamber adjacent the substrate prior to injecting the second gas into the chamber to form a film on the substrate based on an atomic layer deposition the reaction of the first and second gases in the chamber, the controller subsequently activating the third gas source to convert the film in to a different material.

111. The reactor of claim 110, wherein the third gas source supplies an oxidizing gas such that the film is converted to an oxide.

112. The reactor of claim 111, wherein the first gas source supplies a metal that forms the film.

113. The reactor of claim 112, wherein the second gas source supplies a activated hydrogen that removes a component of the first gas so that the metal remains to form the film.

114. A semiconductor device, comprising:

a substrate;

an atomic layer deposition first layer deposited on the substrate, wherein the first layer is deposited sequentially pulsing a first precursor gas and a first reactant into a reaction chamber, and wherein the first precursor gas and the first reactant react to deposit the first layer on the substrate, and wherein the first layer is converted to a second layer by a first converting gas; and

an atomic layer deposition third layer deposited on the second layer, wherein the third layer is deposited sequentially pulsing a second precursor gas and a second reactant into the reaction chamber, and wherein the second precursor gas and the second reactant react to deposit the third layer on the second layer, and wherein the third layer is converted to a fourth layer by a second converting gas.

115. The semiconductor device of claim 114, wherein an atomic layer deposition fifth layer deposited on the fourth layer, wherein the fifth layer is deposited sequentially pulsing the first precursor gas and the first reactant into the reaction chamber, and wherein the first precursor gas and the first reactant react to deposit the fifth layer on the fourth layer, and wherein the fifth layer is converted to a sixth layer by the first converting gas.

116. The semiconductor device of claim 115, wherein a seventh layer is deposited on the sixth layer and is the same as the fourth layer.

117. The semiconductor device of claim 116, wherein an eighth layer is deposited on the seventh layer and is the same as the second layer.

118. The semiconductor device according to claim 114, wherein the first layer is an atomic layer deposition metal layer.

119. The semiconductor device according to claim 118, wherein the second layer is a metal oxide.

120. The semiconductor device according to claim 119, wherein the first and second metal layers include at least one of titanium, tantalum and aluminum.