Laser selection of ions for sputter deposition of titanium containing films

• US 6,752,912 B1
• Filed: 08/27/1999
• Issued: 06/22/2004
• Est. Priority Date: 04/12/1996
• Status: Expired due to Fees

• Current Assignee: MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management)
• Original Assignee: Micron Technology, Inc.
• Inventors: Sandhu, Gurtej S.
• Primary Examiner(s): MCDONALD, RODNEY GLENN
• Application Number:
  US09/384,740
• Time in Patent Office: 1,761 Days
• Field of Search: 204/192.12, 204/192.17, 204/192.15, 204/299.05, 204/298.06, 204/298.11, 204/298.16, 204/298.26, 118/723.R, 118/723.VE, 118/723.MP, 118/726.ER, 427/586, 427/595, 427/596, 427/597, 427/548.1, 427/250
• US Class Current: 204/192.15
• CPC Class Codes: C23C 14/345 using substrate bias
• CPC Class Codes: C23C 14/351 using a magnetic field in close vicinity to the substrate
• CPC Class Codes: C23C 14/354 Introduction of auxiliary energy into the plasma
• CPC Class Codes: H01J 2237/3327 Coating high aspect ratio workpieces
• CPC Class Codes: H01J 37/32339 using electromagnetic radiation

Abstract

In a sputtering apparatus, target particles to be deposited onto a substrate are selectively ionized relative to other particles in the deposition chamber. For example, titanium or titanium-containing target particles are selectively ionized, while inert particles, such as argon atoms, remain substantially unaffected. Advantageously, one or more optical ionizers, such as lasers, are used to create one or more ionization zones within the deposition chamber in which such selective ionization takes place.

Claims

1. An apparatus for depositing film, the apparatus comprising:

a deposition chamber being adapted to hold target particles and other particles; and

an ionizer for creating an ionization zone within the deposition chamber, wherein the ionizer comprises an optical ionizer for creating a plane of optical energy within the deposition chamber, the optical energy selectively ionizing the target particles passing through the plane while leaving the other particles passing through the plane substantially unaffected.

2. The apparatus, as set forth in claim 1, wherein the deposition chamber comprises a support for holding a source of the target particles.

3. The apparatus, as set forth in claim 1, wherein the deposition chamber comprises a support for holding a substrate.

4. The apparatus, as set forth in claim 3, wherein the substrate comprises a semiconductor wafer.

5. The apparatus, as set forth in claim 1, comprising:

a plasma generator creating a plasma within the deposition chamber to initially ionize the target particles.

6. The apparatus, as set forth in claim 5, wherein the ionization zone is separated from the plasma by a recombination zone in which the initially ionized target particles de-ionize prior to being re-ionized in the ionization zone.

7. The apparatus, as set forth in claim 1, wherein the ionizer comprises a laser having a wavelength and power chosen to ionize the target particles in preference to the inert particles.

8. The apparatus, as set forth in claim 7, wherein the laser comprises one of an excimer laser and an EUV laser.

9. The apparatus, as set forth in claim 1, wherein the target particles are titanium-containing particles.

10. The apparatus, as set forth in claim 1, comprising:

a static field generator creating an static field within the deposition chamber to accelerate the ionized target particles along a given trajectory toward the substrate.

11. The apparatus, as set forth in claim 1, wherein the deposition chamber comprises a mirrored inner surface.

12. The apparatus, as set forth in claim 11, wherein the ionizer comprises a laser arranged to direct optical energy onto the mirrored inner surface of the deposition chamber, the mirrored inner surface creating a plane of optical energy.

13. An apparatus for depositing a film on a substrate, the apparatus comprising:

a deposition chamber adapted to contain inert particles, target particles, and a substrate;

a plurality of ionizers creating a plurality of ionization zones within the deposition chamber, each of the plurality of ionizers ionizing the target particles as they pass through each of the respective ionization zones while leaving the inert particles substantially unaffected, wherein the plurality of ionization zones comprise at least one plane of optical energy; and

a static field generator creating an static field within the deposition chamber to accelerate the ionized target particles along a given trajectory to the substrate.

14. The apparatus, as set forth in claim 13, wherein the deposition chamber comprises a support for holding a source of the target particles.

15. The apparatus, as set forth in claims 13, wherein the deposition chamber comprises a support for holding the substrate.

16. The apparatus, as set forth in claim 15, wherein the substrate comprises a semiconductor wafer.

17. The apparatus, as set forth in claim 13, wherein the deposition chamber comprises a port for entry of the inert particles.

18. The apparatus, as set forth in claim 13, comprising:

a plasma generator creating a plasma within the deposition chamber to initially ionize the target particles.

19. The apparatus, as set forth in claim 18, wherein the plurality of ionization zones are separated from the plasma by a recombination zone in which the initially ionized target particles de-ionize prior to being re-ionized in the plurality of ionization zones.

20. The apparatus, as set forth in claim 13, wherein each of the plurality of ionizers comprises:

an optical ionizer for creating a plane of optical energy within the deposition chamber, the optical energy selectively ionizing the target particles passing through the plane while leaving the inert particles passing through the plane substantially unaffected.

21. The apparatus, as set forth in claim 13, wherein each of the plurality of ionizers comprises a laser having a wavelength and power chosen to ionize the target particles in preference to the inert particles.

22. The apparatus, as set forth in claim 21, wherein the laser comprises one of an excimer laser and an EUV laser.

23. The apparatus, as set forth in claim 13, wherein the target particles are titanium-containing particles.

24. The apparatus, as set forth in claim 13, wherein the static field generator comprises:

an electrostatic field generator creating an electrostatic field to accelerate the ionized target particles along a substantially collimated trajectory toward the substrate support.

25. The apparatus, as set forth in claim 13, wherein the static field generator comprises:

a magnetic field generator creating a magnetic field to accelerate the ionized target particles along a substantially collimated trajectory toward the substrate support.

26. The apparatus, as set forth in claim 13, wherein the deposition chamber comprises a mirrored inner surface, and wherein each of the plurality of ionizers comprises a laser arranged to direct optical energy onto the mirrored inner surface of the deposition chamber to create a respective plane of optical energy.

27. An apparatus for depositing a film on a substrate, the apparatus comprising:

a deposition chamber adapted to contain inert particles;

a first support for supporting a substrate within the deposition chamber;

a second support for supporting a source of target particles within the deposition chamber;

an ionizer creating an ionization zone between the first support and the second support, the ionizer ionizing the target particles as they pass through the ionization zone while leaving the inert particles substantially unaffected;

a static field generator creating an static field within the deposition chamber to accelerate the ionized target particles along a substantially collimated trajectory toward the substrate support; and

an electrostatic collimator comprising;

a first conductive grid;

a first DC voltage source having a polarity matching that of the ionized target atoms coupled to the first conductive grid;

a second conductive grid place between the first conductive grid and the substrate support; and

a second DC voltage source having a polarity opposite that of the ionized target atoms coupled to the second conductive grid.

28. The apparatus, as set forth in claim 27, wherein the substrate comprises a semiconductor wafer.

29. The apparatus, as set forth in claim 27, wherein the deposition chamber comprises a port for entry of the inert particles.

30. The apparatus, as set forth in claim 27, comprising:

a plasma generator creating a plasma within the deposition chamber to initially ionize the target particles.

31. The apparatus, as set forth in claim 30, wherein the ionization zone is separated from the plasma by a recombination zone in which the initially ionized target particles de-ionize prior to being re-ionized in the ionization zone.

32. The apparatus, as set forth in claim 27, wherein the ionizer comprises:

an optical ionizer for creating a plane of optical energy within the deposition chamber, the optical energy selectively ionizing the target particles passing through the plane while leaving the inert particles passing through the plane substantially unaffected.

33. The apparatus, as set forth in claim 27, wherein the ionizer comprises a laser having a wavelength and power chosen to ionize the target particles in preference to the inert particles.

34. The apparatus, as set forth in claim 33, wherein the laser comprises one of an excimer laser and an EUV laser.

35. The apparatus, as set forth in claim 27, wherein the target particles are titanium-containing particles.

36. The apparatus, as set forth in claim 27, wherein the static field generator comprises:

an electrostatic field generator creating an electrostatic field to accelerate the ionized target particles along a substantially collimated trajectory toward the substrate support.

37. The apparatus, as set forth in claim 27, wherein the static field generator comprises:

a magnetic field generator creating a magnetic field to accelerate the ionized target particles along a substantially collimated trajectory toward the substrate support.

38. The apparatus, as set forth in claim 27, wherein the deposition chamber comprises a mirrored inner surface, and wherein the ionizer comprises a laser arranged to direct optical energy onto the mirrored inner surface of the deposition chamber to create a plane of optical energy.

39. An apparatus for film deposition comprising:

a deposition chamber for containing target particles and inert particles;

a substrate support within the deposition chamber;

a plurality of ionizers positioned to create plurality of ionization zones within the deposition chamber between the source and the substrate, each of the plurality of ionizers ionizing the target particles in each of the respective plurality of ionization zones to a greater degree than the inert particles in each of the respective plurality of ionization zones, wherein the plurality of ionization zones comprise at least one plane of optical energy; and

an electrostatic field generator creating an electrostatic field to accelerate the ionized target particles along a substantially collimated trajectory toward the substrate support.

40. The apparatus, as set forth in claim 39, wherein the deposition chamber comprises a support for holding a source of the target particles.

41. The apparatus, as set forth in claim 39, wherein the substrate comprises a semiconductor wafer.

42. The apparatus, as set forth in claims 39, comprising:

a plasma generator creating a plasma within the deposition chamber to initially ionize the target particles.

43. The apparatus, as set forth in claim 42, wherein the plurality of ionization zones are separated from the plasma by a recombination zone in which the initially ionized target particles de-ionize prior to being re-ionized in the ionization zone.

44. The apparatus, as set forth in claim 39, wherein each of the plurality of ionizers comprise:

an optical ionizer for creating a plane of optical energy within the deposition chamber, the optical energy selectively ionizing the target particles passing through the plane while leaving the inert particles passing through the plane substantially unaffected.

45. The apparatus, as set forth in claim 39, wherein each of the plurality of ionizers comprise a laser having a wavelength and power chosen to ionize the target particles in preference to the inert particles.

46. The apparatus, as set forth in claim 45, wherein the laser comprises one of an excimer laser and an EUV laser.

47. The apparatus, as set forth in claim 39, wherein the target particles are titanium-containing particles.

48. The apparatus, as set forth in claim 39, wherein the deposition chamber comprises a mirrored inner surface, and wherein each of the plurality of ionizers comprise a laser arranged to direct optical energy onto the mirrored inner surface of the deposition chamber to create a plane of optical energy.

49. An apparatus for film deposition comprising:

a deposition chamber for containing target particles and inert particles;

a substrate support within the deposition chamber;

a plurality of ionizers positioned to create a plurality of ionization zones within the deposition chamber between the source and the substrate, each of the plurality of ionizers ionizing the target particles in each of the respective plurality of ionization zones to a greater degree than the inert particles in each of the respective plurality of ionization zones, wherein the plurality of ionization zones comprise at least one plane of optical energy; and

a magnetic field generator creating a magnetic field within the deposition chamber to accelerate the ionized target particles along a substantially collimated trajectory toward the substrate support.

50. The apparatus, as set forth in claim 49, wherein the deposition chamber comprises a support for holding a source of the target particles.

51. The apparatus, as set forth in claim 49, wherein the substrate comprises a semiconductor wafer.

52. The apparatus, as set forth in claim 49, comprising:

a plasma generator creating a plasma within the deposition chamber to initially ionize the target particles.

53. The apparatus, as set forth in claim 52, wherein the plurality of ionization zones are separated from the plasma by a recombination zone in which the initially ionized target particles de-ionize prior to being re-ionized in the ionization zone.

54. The apparatus, as set forth in claim 49, wherein each of the plurality of ionizers comprise:

an optical ionizer for creating a plane of optical energy within the deposition chamber, the optical energy selectively ionizing the target particles passing through the plane while leaving the inert particles passing through the plane substantially unaffected.

55. The apparatus, as set forth in claim 49, wherein each of the plurality of ionizers comprise a laser having a wavelength and power chosen to ionize the target particles in preference to the inert particles.

56. The apparatus, as set forth in claim 55, wherein the laser comprises one of an excimer laser and an EUV laser.

57. The apparatus, as set forth in claim 49, wherein the target particles are titanium-containing particles.

58. The apparatus, as set forth in claim 49, wherein the deposition chamber comprises a mirrored inner surface, and wherein each of the plurality of ionizers comprise a laser arranged to direct optical energy onto the mirrored inner surface of the deposition chamber to create a plane of optical energy.

59. An apparatus for depositing film, the apparatus comprising:

a deposition chamber being adapted to hold inert particles, a source of target particles, and a substrate for receiving the target particles;

an ionizer positioned to create an ionization zone within the deposition chamber between the source and the substrate, the ionizer ionizing the target particles in the ionization zone to a greater degree than the inert particles in the ionization zone; and

an electrostatic collimator located within the deposition chamber to direct the target particles toward the substrate, wherein the electrostatic collimator comprises;

a first conductive grid;

a first DC voltage source having a polarity matching that of the ionized target atoms coupled to the first conductive grid;

a second conductive grid placed between the first conductive grid and the substrate support; and

a second DC voltage source having a polarity opposite that of the ionized target atoms coupled to the second conductive grid.

60. The apparatus, as set forth in claim 59, wherein the deposition chamber comprises a support for holding the source of the target particles.

61. The apparatus, as set forth in claim 59, wherein the deposition chamber comprises a support for holding the substrate.

62. The apparatus, as set forth in claim 59, wherein the substrate comprises a semiconductor wafer.

63. The apparatus, as set forth in claim 59, comprising:

a plasma generator creating a plasma within the deposition chamber to initially ionize the target particles.

64. The apparatus, as set forth in claim 63, wherein the ionization zone is separated from the plasma by a recombination zone in which the initially ionized target particles de-ionize prior to being re-ionized in the ionization zone.

65. The apparatus, as set forth in claim 59, wherein the ionizer comprises:

an optical ionizer for creating a plane of optical energy within the deposition chamber, the optical energy selectively ionizing the target particles passing through the plane while leaving the inert particles passing through the plane substantially unaffected.

66. The apparatus, as set forth in claim 59, wherein the ionizer comprises a laser having a wavelength and power chosen to ionize the target particles in preference to the inert particles.

67. The apparatus, as set forth in claim 66, wherein the laser comprises one of an excimer laser and an EUV laser.

68. The apparatus, as set forth in claims 59, wherein the target particles are titanium-containing particles.

69. The apparatus, as set forth in claim 59, comprising:

a static field generator creating an static field within the deposition chamber to accelerate the ionized target particles along a given trajectory toward the substrate.

70. The apparatus, as set forth in claim 59, wherein the deposition chamber comprises a mirrored inner surface, and wherein the ionizer comprises a laser arranged to direct optical energy onto the mirrored inner surface of the deposition chamber to create a plane of optical energy.

71. The apparatus, as set forth in claim 59, wherein the collimator is located proximate the plasma.

72. The apparatus, as set forth in claim 59, wherein the collimator is located proximate the substrate.

73. An apparatus for depositing film, the apparatus comprising:

a deposition chamber being adapted to hold inert particles, a source of target particles, and a substrate for receiving the target particles;

a plasma generator for ionizing the target particles and the inert particles;

a recombination zone in which a portion of the target particles and a portion of the inert particles de-ionize; and

a plurality of secondary ionizers for creating a plurality of secondary ionization zones between the source and the substrate, wherein the plurality of secondary ionization zones comprise at least one plane of optical energy, each of the plurality of secondary ionization zones promoting ionization of the target particles as the target particles pass through each of the respective plurality of secondary ionization zones while leaving the inert particles substantially unaffected as the inert particles pass through each of the respective plurality of secondary ionization zones.

74. An apparatus for depositing film, the apparatus comprising:

a deposition chamber being adapted to hold inert particles, a source of target particles, and a substrate for receiving the target particles;

a plasma generator for initially ionizing the target particles;

a first secondary optical ionizer for creating a first plane of optical energy positioned to overlie the substrate, the first plane of optical energy ionizing the target particles passing through the first plane while leaving the inert particles passing through the first plane substantially unaffected; and

a second secondary optical ionizer for creating a second plane of optical energy positioned to overlie the substrate, the second plane of optical energy ionizing the target particles passing through the second plane while leaving the inert particles passing through the second plane substantially unaffected.

75. A method for depositing a film onto a substrate comprising the acts of:

(a) passing target particles and inert particles through plurality of ionization zones in a deposition chamber to ionize the target particles while leaving the inert particles substantially unaffected in each of the plurality of ionization zone at least one of the plurality of ionization zones comprise at least one plane of optical energy; and

(b) steering the ionized target particles into a collimated stream directed along a given path toward the substrate.

76. The method, as set forth in claim 75, wherein act (a) comprises the act of:

initially ionizing the target particles and the inert particles using a plasma.

77. The method, as set forth in claim 76, wherein act (a) comprises the act of:

de-ionizing the target particles and the inert particles in a recombination zone located between the plasma and the plurality of ionization zones.

78. The method, as set forth in claim 77, wherein act (a) comprises the act of:

energizing the target particles in each of the plurality of ionization zones to a greater degree than the inert particles in the respective ionization zone.

79. The method, as set forth in claim 75, wherein act (a) comprises the act of:

utilizing a tuned laser to ionize the target particles while leaving the inert particles substantially unaffected.

80. The method, as set forth in claim 75, wherein act (b) comprises the act of:

electrostatically steering the ionized target particles.

81. The method, as set forth in claim 80, wherein the act of electrostatically steering comprises the act of charging the substrate.

82. The method, as set forth in claim 80, wherein the act of electrostatically steering comprises the act of:

passing the ionized target particles through an electrostatic collimator.

83. The method, as set forth in claim 75, wherein act (b) comprises the act of:

magnetically steering the ionized target particles.

84. The method, as set forth in claim 75, wherein act (b) comprises the act of:

passing the target particles through a lattice-type collimator.