Method and apparatus for vaporizing liquid precursors and system for using same

• US 20010020448A1
• Filed: 05/16/2001
• Published: 09/13/2001
• Est. Priority Date: 10/02/1996
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Atwell, David, Vaartstra, Brian A.
• Granted Patent: US 6,402,126 B2
• Time in Patent Office: Days
• US Class Current: 118/724
• CPC Class Codes: C23C 16/4486 by producing an aerosol and subsequent evaporation of the droplets or particles

Abstract

A vaporizing apparatus for providing a vaporized liquid precursor to a process chamber in a vapor deposition process includes a microdroplet forming device for generating microdroplets from a liquid precursor and a heated housing defining a vaporization zone having a vapor flow path from the microdroplet forming device to the process chamber. The vaporization zone receives the microdroplets and a heated carrier gas. The heated carrier gas has a temperature so as to provide the primary source of heat for vaporizing the microdroplets. A method of vaporizing liquids for vapor deposition processes includes generating microdroplets and utilizing a heated carrier gas as the primary source of heat for vaporizing the microdroplets. A vapor deposition system carrying out the method includes a heated carrier gas and a heated housing defining a heated vaporization zone. The heated housing receives the heated carrier gas. An atomizer for generating microdroplets from a liquid source dispenses the microdroplets in the heated vaporization zone. The heated carrier gas has a temperature so as to provide the primary source of heat for vaporizing the microdroplets in the vaporization zone. The vaporized liquid precursor is then directed to the process chamber from the heated vaporization zone.

Claims

1. A vaporizing apparatus for providing a vaporized liquid precursor to a process chamber in a vapor deposition process, the apparatus comprising:

a microdroplet forming device configured to generate microdroplets from a liquid precursor; and

a heated housing defining a vaporization zone having a vapor flow path from the microdroplet forming device to the process chamber, the vaporization zone for receiving the microdroplets and a heated carrier gas, the heated carrier gas for vaporizing at least a portion of the microdroplets.

2. The apparatus according to

claim 1

, wherein the heated carrier gas is an inert gas with high thermal conductivity.

3. The apparatus according to

claim 2

, wherein the heated carrier gas is helium.

4. The apparatus according to

claim 1

, wherein the microdroplet forming device includes a dispensing device sealingly positioned in the vaporization zone to dispense the microdroplets into the vaporization zone, the heated housing having a carrier gas port for receiving the heated carrier gas to vaporize the microdroplets in the vaporization zone, and further wherein the heated housing includes a directing device to direct the vaporized microdroplets into the process chamber.

5. The apparatus according to

claim 4

, wherein the apparatus further includes:

a gas flow controller for controlling a flow rate of the heated carrier gas to the vaporization zone, the heated carrier gas being provided to the vaporization zone through a heated gas line connected to the heated carrier gas port; and

a liquid flow controller for providing the liquid to the microdroplet forming device at a desired flow rate.

6. The apparatus according to

claim 4

, wherein the dispensing device includes an opening for dispensing the microdroplets, the opening being positioned in close proximity to the carrier gas port.

7. The apparatus according to

claim 1

, wherein the microdroplets formed include droplets having a diameter of less than 1000 micrometers.

8. The apparatus according to

claim 1

, wherein the microdroplet forming device preheats the microdroplets prior to being introduced into the vaporization zone.

9. The apparatus according to

claim 1

, wherein the heated vaporization zone is physically separate from the process chamber.

10. The apparatus according to

claim 9

, wherein the heated vaporization zone is located at least in part within the process chamber but is physically separate therefrom.

11. The apparatus according to

claim 1

, wherein the heated housing includes at least one wall, the at least one wall being heated by at least one heating element to maintain a substantially constant temperature along the vapor flow path.

12. The apparatus according to

claim 11

, wherein the apparatus includes at least one monitor for detecting the temperature along the vapor flow path, the at least one heating element changing the temperature of the vapor flow path in response to the detected temperature.

13. The apparatus according to

claim 1

, wherein the microdroplet forming device includes one of an electrostatic sprayer and an ultrasonic nebulizer.

14. The apparatus according to

claim 1

, wherein the apparatus further includes:

a detection device for detecting the concentration of unvaporized microdroplets and generating a signal representative thereof; and

a controller responsive to the signal representative of the detected concentration for initiating modification of a parameter of the vaporizing apparatus.

15. The apparatus according to

claim 14

, wherein the apparatus further includes means for modifying a length of the vapor flow path in response to the a signal from the controller.

16. The apparatus according to

claim 15

, wherein the modifying means includes means for repositioning an opening of the microdroplet forming device within the vaporization zone.

17. The apparatus according to

claim 15

, wherein the modifying means includes means for modifying a length of the heated housing.

18. The apparatus according to

claim 14

, wherein the apparatus further includes means for changing the temperature along the vapor flow path in response to a signal from the controller.

19. The apparatus according to

claim 1

, wherein the apparatus further comprises a detector for detecting undesired particulates in the vapor flow path.

20. A method of vaporizing liquid precursors for vapor deposition processes, the method comprising the steps of:

generating microdroplets; and

vaporizing at least a portion of the microdroplets using a heated carrier gas.

21. The method according to

claim 20

, wherein the heated carrier gas is an inert gas with high thermal conductivity.

22. The method according to

claim 21

, wherein the heated carrier gas is helium.

23. The method according to

claim 20

, wherein the generating step includes generating the microdroplets electrostatically.

24. The method according to

claim 20

, wherein the generating step includes generating the microdroplets ultrasonically.

25. The method according to

claim 20

, wherein the generating step includes generating the microdroplets having a diameter less than about 1000 micrometers.

26. The method according to

claim 20

, wherein the generating step includes dispensing the microdroplets in a heated vaporization zone;

and further wherein the vaporization step includes mixing the heated carrier gas with the microdroplets in the heated vaporization zone.

27. The method according to

claim 26

, wherein the vaporization step further includes the step of providing the heated carrier gas to the vaporization zone at a flow rate to substantially prevent decomposition of the microdroplets at heated walls defining the vaporization zone.

28. The method according to

claim 20

, wherein the vaporization step includes maintaining a substantially constant temperature of the mixture of the heated carrier gas and the microdroplets throughout the vaporization zone.

29. The method according to

claim 26

, further including the step of directing the mixture of the heated carrier gas and vaporized microdroplets in the vaporization zone to one or more process chambers having a deposition surface positioned therein.

30. The method according to

claim 20

, wherein the generating step includes preheating the microdroplets.

31. The method according to

claim 20

, wherein the method further comprises the steps of:

detecting the concentration of unvaporized microdroplets; and

controlling the vaporization step as a function of the detected concentration.

32. The method according to

claim 31

, wherein the vaporization step is performed in a heated vaporization zone, and further wherein the controlling step includes controlling the temperature of the heated vaporization zone.

33. The method according to

claim 31

, wherein the controlling step includes controlling the temperature of the heated carrier gas.

34. The method according to

claim 31

, wherein the vaporization step is performed in a heated vaporization zone, and further wherein the controlling step includes controlling a time period the microdroplets are in the heated vaporization zone.

35. The method according to

claim 34

, wherein the time period controlling step includes changing a size of the vaporization zone.

36. The method according to

claim 34

, wherein the time period controlling step includes changing a position in the vaporization zone at which the microdroplets are introduced therein.

37. The method according to

claim 20

, wherein the method further comprises the step of detecting undesired particulates in the vaporized liquid.

38. A vapor deposition system comprising:

a heated carrier gas;

a heated housing defining a heated vaporization zone, the heated housing including a port for introducing the heated carrier gas in the heated vaporization zone;

an atomizer for generating microdroplets from a liquid precursor and dispensing the microdroplets in the heated vaporization zone, the heated carrier gas for vaporizing the at least a portion of the microdroplets in the vaporization zone resulting in a vaporized liquid precursor; and

a process chamber for receiving the vaporized liquid from the heated vaporization zone.

39. The system according to

claim 38

, wherein the heated vaporization zone is physically separate from the process chamber.

40. A method of vaporizing liquid precursors for vapor deposition processes, the method comprising the steps of:

generating microdroplets; and

using a heated carrier gas as the primary source of heat to vaporize the microdroplets.

41. The method according to

claim 40

, wherein the heated carrier gas is an inert gas with high thermal conductivity.

42. The method according to

claim 40

, wherein the generating step includes generating the microdroplets having a diameter less than about 1000 micrometers.

43. The method according to

claim 40

, wherein the generating step includes preheating the microdroplets.

44. A method of controlling the vaporization of liquid precursors for vapor deposition processes, the method comprising the steps of:

using a heated carrier gas to vaporize microdroplets;

detecting the concentration of unvaporized microdroplets; and

controlling the use of the heated carrier gas to vaporize the microdroplets as a function of the detected concentration.

45. The method according to

claim 44

, wherein the vaporization of microdroplets by using the heated carrier gas is performed in a heated vaporization zone, and further wherein the controlling step includes controlling the temperature of the heated vaporization zone.

46. The method according to

claim 44

, wherein the controlling step includes controlling the temperature of the heated carrier gas.

47. The method according to

claim 44

, wherein the vaporization of microdroplets by using the heated carrier gas is performed in a heated vaporization zone, and further wherein the controlling step includes controlling a time period the microdroplets are in the heated vaporization zone.

48. The method according to

claim 47

, wherein the time period controlling step includes changing a size of the vaporization zone.

49. The method according to

claim 47

, wherein the time period controlling step includes changing a position in the vaporization zone at which the microdroplets are introduced therein.

50. The method according to

claim 44

, wherein the method further comprises the step of detecting undesired particulates in the vaporized liquid.

51. A method of vaporizing liquid precursors for vapor deposition processes, the method comprising the steps of:

providing microdroplets, the microdroplets having a diameter less than about 1000 micrometers;

heating an inert carrier gas having high thermal conductivity;

mixing the microdroplets with the heated carrier gas, the heated carrier gas being heated to a temperature so as to provide the primary source of heat for vaporizing the microdroplets.

52. The method according to

claim 51

, wherein the providing step includes providing microdroplets having a diameter less than about 100 micrometers.

53. The method according to

claim 51

, wherein the providing step includes dispensing the micro droplets in a heated vaporization zone for mixing with the heated carrier gas, the heated carrier gas provided to the vaporization zone at a flow rate to substantially prevent decomposition of the microdroplets at heated walls defining the vaporization zone.

54. The method according to

claim 53

, wherein the vaporization step includes maintaining a substantially constant temperature of the mixture of the heated carrier gas and the microdroplets throughout the vaporization zone.

55. A vaporizing apparatus for providing a vaporized liquid precursor to a process chamber in a vapor deposition process, the apparatus comprising:

a microdroplet forming device configured to generate microdroplets from a liquid precursor;

a heated housing defining a vaporization zone having a vapor flow path from the microdroplet forming device to the process chamber, the vaporization zone for receiving the microdroplets and a heated carrier gas, the heated carrier gas for vaporizing at least a portion of the microdroplets; and

a detector for detecting undesired particulates in the vapor flow path.

56. The apparatus according to

claim 55

, wherein the heated carrier gas is an inert gas with high thermal conductivity.

57. The apparatus according to

claim 56

, wherein the heated carrier gas is helium.

58. The apparatus according to

claim 55

, wherein the microdroplet forming device comprises a dispensing device sealingly positioned in the vaporization zone to dispense the microdroplets into the vaporization zone, the heated housing having a carrier gas port for receiving the heated carrier gas to vaporize the microdroplets in the vaporization zone, and further wherein the heated housing includes a directing device to direct the vaporized microdroplets into the process chamber.

59. The apparatus according to

claim 58

, wherein the apparatus further comprises:

a gas flow controller for controlling a flow rate of the heated carrier gas to the vaporization zone, the heated carrier gas being provided to the vaporization zone through a heated gas line connected to the carrier gas port; and

a liquid flow controller for providing the liquid precursor to the microdroplet forming device at a desired flow rate.

60. The apparatus according to

claim 58

, wherein the dispensing device comprises an opening for dispensing the microdroplets, the opening being positioned in close proximity to the carrier gas port.

61. The apparatus according to

claim 55

, wherein the microdroplets formed comprise droplets having a diameter of less than 1000 micrometers.

62. The apparatus according to

claim 55

, wherein the microdroplet forming device preheats the microdroplets prior to being introduced into the vaporization zone.

63. The apparatus according to

claim 55

, wherein the vaporization zone is physically separate from the process chamber.

64. The apparatus according to

claim 63

, wherein the vaporization zone is located at least in part within the process chamber but is physically separate therefrom.

65. The apparatus according to

claim 55

, wherein the heated housing comprises at least one wall, the at least one wall being heated by at least one heating element to maintain a substantially constant temperature along the vapor flow path.

66. The apparatus according to

claim 65

, wherein the apparatus comprises at least one monitor for detecting the temperature along the vapor flow path, the at least one heating element changing the temperature of the vapor flow path in response to the detected temperature.

67. The apparatus according to

claim 55

, wherein the microdroplet forming device comprises one of an electrostatic sprayer and an ultrasonic nebulizer.

68. A method of vaporizing liquid precursors for vapor deposition processes, the method comprising:

generating microdroplets;

vaporizing at least a portion of the microdroplets using a heated carrier gas; and

detecting undesired particulates in the vaporized microdroplets.

69. The method according to

claim 68

, wherein the heated carrier gas is an inert gas with high thermal conductivity.

70. The method according to

claim 69

, wherein the heated carrier gas is helium.

71. The method according to

claim 68

, wherein generating microdroplets comprises generating microdroplets electrostatically.

72. The method according to

claim 68

, wherein generating microdroplets comprises generating microdroplets ultrasonically.

73. The method according to

claim 68

, wherein generating microdroplets comprises generating microdroplets having a diameter less than about 1000 micrometers.

74. The method according to

claim 68

, wherein generating microdroplets comprises dispensing the microdroplets in a heated vaporization zone;

and further wherein vaporizing at least the portion of the microdroplets includes mixing the heated carrier gas with the microdroplets in the heated vaporization zone.

75. The method according to

claim 74

, wherein vaporizing at least the portion of the microdroplets further comprises providing the heated carrier gas to the heated vaporization zone at a flow rate to substantially prevent decomposition of the microdroplets at heated walls defining the heated vaporization zone.

76. The method according to

claim 74

, wherein vaporizing at least the portion of the microdroplets includes maintaining a substantially constant temperature of a mixture of the heated carrier gas and the microdroplets throughout the heated vaporization zone.

77. The method according to

claim 74

, further comprising directing a mixture of the heated carrier gas and vaporized microdroplets in the heated vaporization zone to one or more process chambers having a deposition surface positioned therein.

78. The method according to

claim 68

, wherein generating microdroplets comprises preheating the microdroplets.