Apparatus and method for vacuum coating deposition

• US 6,736,943 B1
• Filed: 03/12/2002
• Issued: 05/18/2004
• Est. Priority Date: 03/15/2001
• Status: Expired due to Term

• Current Assignee: II-VI Delaware, Inc. (Coherent Corp.)
• Original Assignee: Cierra Photonics, Inc. (Lumentum Holdings Inc.)
• Inventors: Soberanis, David L., Kastanis, William P., Greenberg, Thomas L., Whitlock, Daniel V., Wescott, Elizabeth M., Scobey, Michael A.
• Primary Examiner(s): VERSTEEG, STEVEN H
• Application Number:
  US10/095,828
• Time in Patent Office: 798 Days
• Field of Search: 204/192.12, 204/298.02, 204/298.03, 204/298.09, 204/298.15, 204/298.16, 204/298.17, 204/298.23, 204/298.28
• US Class Current: 204/192.12
• CPC Class Codes: C23C 14/34 Sputtering
• CPC Class Codes: C23C 14/3464 using more than one target C23C14/56 takes precedence
• CPC Class Codes: C23C 14/54 Controlling or regulating the coating process
• CPC Class Codes: C23C 14/547 using optical methods
• CPC Class Codes: G01J 3/26 using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters
• CPC Class Codes: H01J 2237/0216 Means for avoiding or correcting vibration effects
• CPC Class Codes: H01J 37/3405 Magnetron sputtering

Abstract

Vacuum coating deposition apparatus and methods employ a vacuum chamber with a superstructure to which deposition components in the vacuum chamber are mounted, such as a sputter target, substrate, etc. to provide a fixed relative position between them substantially unaffected by environmental and operating vibrations and flexure of the chamber wall. The superstructure is structurally independent of the deposition chamber wall and may be housed within the chamber or externally, extending from an external position to or through the wall of the deposition chamber. A meter of sensor, e.g., an optical monitor for measuring film thickness during deposition, continually monitors at least one parameter of the coating deposition and generates a corresponding control signal. A controller responsive to the control signal continually controls at least one process variable of the coating deposition in response to the control signal.

Claims

1. Apparatus for vacuum deposition of thin film coatings onto a surface of a substrate, comprising:

a vacuum-tight deposition chamber having a chamber wall;

vacuum coating deposition components disposed within the deposition chamber, including at least a substrate mount to hold a substrate with a working surface exposed in the chamber and a coating material source apparatus comprising a target mount to hold a coating material target in the deposition chamber for PVD coating of a working surface of a substrate exposed in the chamber; and

a superstructure structurally isolated from the deposition chamber, the substrate mount and the target mount each being rigidly mounted to the superstructure in fixed position relative to each other.

2. The apparatus for vacuum deposition of thin film coatings in accordance with claim 1 wherein the superstructure is housed entirely within the deposition chamber.

3. The apparatus for vacuum deposition of thin film coatings in accordance with claim 1 wherein at least a portion of the superstructure is external to the deposition chamber.

4. The apparatus for vacuum deposition of thin film coatings in accordance with claim 3 wherein a chamber portion of the superstructure is vacuum sealed to the chamber wall.

5. The apparatus for vacuum deposition of thin film coatings in accordance with claim 4 wherein the superstructure is vacuum sealed to the chamber wall by at least one bellow seal.

6. The apparatus for vacuum deposition of thin film coatings in accordance with claim 1 further comprising:

a monitor for continual monitoring of at least one parameter of a coating deposition operation in the deposition chamber and for generating a corresponding control signal; and

controller responsive to the control signal for continual control of at least one process variable of a coating deposition operation in the deposition chamber.

7. The apparatus for vacuum deposition of thin film coatings in accordance with claim 1 wherein the substrate mount and the target mount are mounted to the superstructure in adjustably fixed relative position.

8. The apparatus for vacuum deposition of thin film coatings in accordance with claim 7 further comprising a position adjustor responsive to a control signal corresponding to at least one parameter of a coating deposition operation in the deposition chamber, to adjust the position of the substrate mount and the target mount relative to each other during a coating deposition operation in the deposition chamber.

9. The apparatus for vacuum coating deposition of thin film coatings in accordance with claim 8 wherein the target mount is mounted to a rigid beam of the superstructure extending into the deposition chamber and the substrate mount is not mounted to the rigid beam, and the position of the substrate mount and the target mount relative to each other is adjusted by movement of the rigid beam.

10. The apparatus for vacuum coating deposition of thin film coatings in accordance with claim 8 wherein the target mount is mounted to a sleeve axially adjustably carried on a rigid beam of the superstructure extending into the deposition chamber, and the substrate mount is not mounted to the sleeve, and the position of the substrate mount and the target mount relative to each other is adjusted by movement of the sleeve.

11. The apparatus for vacuum coating deposition of thin film coatings in accordance with claim 8 wherein the position adjustor comprises a linear motor forming a mounting link between the target mount and the superstructure.

12. The apparatus for vacuum coating deposition of thin film coatings in accordance with claim 8 wherein the position adjustor comprises a stepper motor with screw actuator forming a mounting link between the target mount and the superstructure.

13. The apparatus for vacuum coating deposition of thin film coatings in accordance with claim 8 wherein the position adjustor comprises a ball screw motor forming a mounting link between the target mount and the superstructure.

14. The apparatus for vacuum deposition of thin film coatings in accordance with claim 8 wherein the distance between a working surface of a sputtering target mounted in the target mount and a substrate working surface of a substrate mounted in the substrate mount is adjustable by the position adjustor.

15. The apparatus for vacuum coating deposition of thin film coatings in accordance with claim 14 wherein the deposition chamber is supported by the superstructure.

16. The apparatus for vacuum deposition of thin film coatings in accordance with claim 8 wherein the orientation of a working surface of a sputtering target mounted in the substrate mount relative to a substrate working surface of a substrate mounted in the target mount is adjustable by the position adjustor.

17. The apparatus for vacuum deposition of thin film coatings in accordance with claim 1 wherein the superstructure is anchored in the ground.

18. The apparatus for vacuum deposition of thin film coatings in accordance with claim 1 further comprising a film monitor rigidly mounted to the superstructure in fixed position relative to the substrate mount and the target mount.

19. The apparatus for vacuum deposition of thin film coatings in accordance with claim 1 further comprising temperature control fluid delivery conduit and a temperature control fluid pump actuated in response to the temperature of the superstructure.

20. The apparatus for vacuum deposition of thin film coatings in accordance with claim 1 further comprising a temperature control fluid pump, wherein at least a chamber portion of the superstructure comprises rigid hollow beams in fluid communication with the temperature control fluid pump.

21. The apparatus for vacuum deposition of thin film coatings in accordance with claim 1 wherein the superstructure comprises temperature control fluid channels and a cooling fluid pump in fluid communication with the cooling channels.

22. The apparatus for vacuum deposition of thin film coatings in accordance with claim 1 wherein the target mount comprises cooling channels and a cooling fluid pump in fluid communication with the cooling channels.

23. The apparatus for vacuum deposition of thin film coatings in accordance with claim 1 wherein the superstructure further comprises an anchor portion external to the deposition chamber.

24. The apparatus for vacuum coating deposition of thin film coatings in accordance with claim 1 wherein the coating material source apparatus is an ion beam sputtering (“

IBS”

) device.

25. The apparatus for vacuum coating deposition of thin film coatings in accordance with claim 1 wherein the substrate mount is a rotary drive mount.

26. The apparatus for vacuum coating deposition of thin film coatings in accordance with claim 1 wherein the coating material source apparatus is a magnetron sputtering cathode, the target mount is adapted to mount a sputtering target to present a sputtering target working surface in the chamber, and the sputtering apparatus comprises a magnetron sputtering cathode comprising a magnet assembly positioned behind the target mount to exert an electromagnetic confining force at the sputtering target working surface during coating deposition.

27. The apparatus for vacuum coating deposition of thin film coatings in accordance with claim 26 wherein the target mount is mounted to the superstructure through the magnetron sputtering cathode, and the magnetron sputtering cathode is mounted to the superstructure via a magnetron mount comprising cooling fluid channels in fluid communication with a fluid pump actuated in response to a control signal from a temperature signal exposed to the temperature of the magnetron mount.

28. The apparatus for vacuum coating deposition of thin film coatings in accordance with claim 26 wherein the magnetron mount comprises a screw drive for axial adjustment of the position of the magnet assembly relative the superstructure independent of the position of the target working surface relative the superstructure.

29. Apparatus for vacuum coating deposition of thin film coatings on a surface of a substrate, comprising:

a vacuum-tight deposition chamber having a chamber wall;

vacuum coating deposition components disposed within the deposition chamber, including at least a substrate mount to hold a substrate with a working surface exposed in the chamber and a coating material source apparatus comprising a target mount to hold a coating material target in the deposition chamber for PVD coating of a working surface of a substrate exposed in the chamber; and

a superstructure structurally isolated from the deposition chamber, the substrate mount and the target mount each being rigidly mounted to the superstructure in fixed position relative to each other, and the superstructure comprising at least an anchor portion external to the deposition chamber and a chamber portion vacuum sealed to the chamber wall.

30. The apparatus for vacuum coating deposition of thin film coatings in accordance with claim 29 wherein the substrate mount comprises a rotateable mount for a wafer substrate and the target mount comprises sputtering apparatus.

31. The apparatus for vacuum coating deposition of thin film coatings in accordance with claim 30 wherein the rotateable mount for a wafer substrate is rigidly mounted to a first member of the superstructure extending through the chamber wall with a first vacuum seal at a first location, and the sputtering apparatus is rigidly mounted to a second member of the superstructure extending through the wall of the vacuum coating deposition chamber with a second vacuum seal at a second location.

32. The apparatus for vacuum coating deposition of thin film coatings in accordance with claim 29 Wherein the vacuum seal comprises flexible sheet steel having a radially inward portion secured in a vacuum-tight manner to a member of the superstructure proximate the chamber wall and having a radially outer portion secured in a vacuum-tight manner to the chamber wall.

33. Sputter deposition apparatus comprising:

a vacuum-tight deposition chamber having a chamber wall;

vacuum coating deposition components disposed within the deposition chamber, including at least a substrate mount to hold a substrate with a working surface exposed in the chamber and a coating material source apparatus comprising a target mount to hold a coating material target in the deposition chamber for PVD coating of a working surface of a substrate exposed in the chamber,

a monitor for continual monitoring of at least one parameter of a coating deposition operation in the deposition chamber and for generating a corresponding control signal;

controller responsive to the control signal for continual control of at least one process variable of a coating deposition operation in the deposition chamber; and

a superstructure structurally isolated from the deposition chamber, the substrate mount and the target mount each being rigidly mounted to the superstructure in fixed position relative to each other.

34. The sputter deposition apparatus of claim 33 wherein the monitor for continual monitoring of at least one parameter of a coating deposition operation is for monitoring actual or optical thickness of a film at a first radius R₁ greater than or equal to zero distance units from the center of a substrate and at a second radius R₂ greater than R₁.

35. The sputter deposition apparatus of claim 33 wherein the monitor for continual monitoring of at least one parameter of a coating deposition operation is for monitoring actual or optical thickness of a film at the center of a substrate and at a distance R greater than zero from the center of a substrate.

36. The sputter deposition apparatus of claim 33 wherein the monitor for continual monitoring of at least one parameter of a coating deposition operation is for monitoring distance between a working surface of a sputtering target and a working surface of a substrate during deposition of a film.

37. The sputter deposition apparatus of claim 33 wherein the monitor for continual monitoring of at least one parameter of a coating deposition operation is for monitoring distance between a working surface of a sputtering target and magnets of a magnetron sputtering cathode during deposition of a film.

38. The sputter deposition apparatus of claim 33 wherein the monitor for continual monitoring of at least one parameter of a coating deposition operation is for monitoring temperature of a sputtering target during deposition of a film.

39. The sputter deposition apparatus of claim 33 wherein the monitor for continual monitoring of at least one parameter of a coating deposition operation is for monitoring temperature of magnets of a magnetron sputtering cathode during deposition of a film.

40. The sputter deposition apparatus of claim 33 wherein the controller responsive to the control signal for continual control of at least one process variable of a coating deposition operation is for continual control of the position of a working surface of a sputtering target and the working surface of a substrate relative each other.

41. The sputter deposition apparatus of claim 40 wherein the controller for continual control of the position of a working surface of a sputtering target and the working surface of a substrate relative each other is for controlling distance between them.

42. The sputter deposition apparatus of claim 40 wherein the controller for continual control is for controlling orientation of a working surface of a sputtering target mounted in the target mount relative to a working surface of a substrate mounted in the target mount.

43. The sputter deposition apparatus of claim 33 wherein the coating material source apparatus comprises a magnetron sputtering cathode and the controller responsive to the control signal for continual control of at least one process variable of a coating deposition operation is for continual control of the position of a target working surface of a sputtering target mounted in the target mount and magnets of the magnetron sputtering cathode relative each other.

44. The sputter deposition apparatus of claim 43 wherein the controller for continual control of the position of a working surface of a sputtering target and magnets of the magnetron sputtering cathode relative each other is for controlling distance between them.

45. The sputter deposition apparatus of claim 43 wherein the controller for continual control is for controlling orientation of a working surface of a sputtering target mounted in the target mount relative to magnets of the magnetron sputtering cathode.

46. The sputter deposition apparatus of claim 33 wherein the controller responsive to the control signal for continual control of at least one process variable of a coating deposition operation adjusts the position of a working surface of a sputtering target mounted in the target mount.

47. The sputter deposition apparatus of claim 33 wherein the controller responsive to the control signal for continual control of at least one process variable of a coating deposition operation adjusts the position of a working surface of a substrate mounted in the substrate mount.

48. The sputter deposition apparatus of claim 33 wherein the coating material source apparatus comprises a magnetron sputtering cathode having magnets mounted behind the target mount, and the controller responsive to the control signal for continual control of at least one process variable of a coating deposition operation adjusts the position of the magnets.

49. The sputter deposition apparatus of claim 33 wherein the coating material source apparatus comprises a sputtering apparatus and the controller responsive to the control signal for continual control of at least one process variable of a coating deposition operation is for continual control of power to the sputtering apparatus.

50. The sputter deposition apparatus of claim 33 wherein the coating material source apparatus comprises a magnetron sputtering cathode and the controller responsive to the control signal for continual control of at least one process variable of a coating deposition operation is for continual control of the temperature of the magnets of the magnetron sputtering cathode.

51. The sputter deposition apparatus of claim 33 wherein the controller responsive to the control signal for continual control of at least one process variable of a coating deposition operation is for continual control of the temperature of a coating material mounted in the target mount.

52. The sputter deposition apparatus of claim 33 wherein the controller responsive to the control signal for continual control of at least one process variable of a coating deposition operation is a substrate temperature controller for continual control of the temperature of a substrate mounted in the substrate mount, wherein the substrate temperature controller is operative to maintain a substantially constant substrate temperature during at least a predetermined portion of the coating deposition operation, and wherein the substrate temperature controller is operative to deliver temperature control fluid to the substrate mount.

53. The sputter deposition apparatus of claim 33 wherein the controller responsive to the control signal for continual control of at least one process variable of a coating deposition operation is for controlling the process variable continuously during at least a portion of the deposition of a film.

54. The sputter deposition apparatus of claim 33 wherein the controller responsive to the control signal for continual control of at least one process variable of a coating deposition operation is for controlling the process variable periodically during at least a portion of the deposition of a film.

55. The sputter deposition apparatus of claim 33 wherein the controller responsive to the control signal for continual control of at least one process variable of a coating deposition operation is for controlling the process variable continuously during at least a portion of the deposition of a film.

56. The sputter deposition apparatus of claim 33 wherein the controller responsive to the control signal for continual control of at least one process variable of a coating deposition operation is for maintaining the process variable substantially constant.

57. The sputter deposition apparatus of claim 33 wherein the controller responsive to the control signal for continual control of at least one process variable of a coating deposition operation is for adjusting the process variable to control film deposition rate onto a substrate working surface.

58. Vacuum coating deposition apparatus comprising:

a vacuum-tight sputtering deposition chamber having a chamber wall;

an optical glass wafer substrate mounted in a substrate mount and having a substrate working surface exposed in the chamber for coating,

a sputtering target mounted in a target mount of a sputtering apparatus and having a target working surface in the chamber;

an optical monitor for continual monitoring of actual or optical film thickness at two locations on the substrate working surface during deposition of a film onto the substrate working surface and for generating a corresponding control signal; and

a controller for continual adjustment during at least a portion of a coating deposition operation in the deposition chamber to control the position of the target working surface relative to the substrate working surface.

59. The vacuum coating apparatus of claim 58 wherein the controller for continual adjustment of the position of the target working surface relative to the substrate working surface comprises a computer actuated automatic adjustment controller responsive to the control signal, for moving the sputtering target.

60. The vacuum coating apparatus of claim 58 further comprising a graphical user interface displaying the control signal, wherein the controller for continual adjustment of the position of the target working surface relative to the substrate working surface comprises an operator actuated adjustment controller for moving the sputtering target.

61. The vacuum coating apparatus of claim 58 further comprising at least one additional sputtering target mounted in a target mount of a sputtering apparatus and having a target working surface in the chamber.

62. Vacuum coating deposition apparatus comprising:

a vacuum-tight sputtering deposition chamber having a chamber wall;

an optical glass wafer substrate mounted in a substrate mount and having a substrate working surface exposed in the chamber for coating;

a sputtering target mount;

a sputtering target mounted by the target mount having a target working surface in the chamber;

an optical monitor for continual monitoring of actual or optical film thickness at two locations on the substrate working surface during deposition of a film onto the substrate working surface and for generating corresponding control signals, the target mount being operative to adjust the position of the target working surface relative to the substrate working surface in closed-loop response to the control signals received from the optical monitor corresponding to film thickness.

63. Vacuum coating deposition apparatus comprising:

a vacuum-tight sputtering deposition chamber having a chamber wall;

a substrate mounted in a substrate mount and having a working surface exposed in the chamber for coating;

a magnetron sputtering cathode having a target mount adapted to mount a sputtering target to present a sputtering target working surface in the chamber, and having a magnet assembly positioned behind the target mount to exert a confining force at the sputtering target working surface during operation of the vacuum coating deposition apparatus;

a monitor for continual monitoring of at least one parameter of a coating deposition operation in the deposition chamber and for generating a corresponding control signal; and

a controller for continual adjustment during at least a portion of a coating deposition operation in the deposition chamber to control the position of the target working surface relative to the magnet assembly.

64. The vacuum coating apparatus of claim 63 wherein the controller for continual adjustment of the position of the target working surface relative to the magnet assembly comprises a computer actuated automatic adjustment controller, responsive to the control signal, for moving the sputtering target.

65. The vacuum coating apparatus of claim 63 further comprising a graphical user interface displaying the control signal, wherein the controller for continual adjustment of the position of the target working surface relative to the magnet assembly comprises operator actuated adjustment controller for moving the sputtering target.

66. A method for vacuum deposition of thin film coatings onto a surface of a substrate, comprising:

providing a vacuum-tight deposition chamber having a chamber wall;

mounting vacuum coating deposition components within the deposition chamber to a superstructure structurally isolated from the deposition chamber, including at least a substrate mount holding a substrate with a substrate working surface exposed in the chamber and a coating material source apparatus comprising a target mount holding a coating material target in the deposition chamber, the substrate mount and the target mount each being rigidly mounted to the superstructure in fixed position relative to each other, and

energizing the coating material source apparatus and coating the substrate working surface.

67. A method for vacuum deposition of thin film coatings onto a surface of a substrate, comprising:

providing a vacuum-tight deposition chamber having a chamber wall;

mounting vacuum coating deposition components within the deposition chamber, including at least a substrate mount holding a substrate with a substrate working surface exposed in the chamber and a coating material source apparatus comprising a target mount holding a coating material target in the deposition chamber;

energizing the coating material source apparatus and commencing deposition of a coating onto the substrate working surface;

continually monitoring physical or optical film thickness uniformity of a film of a film stack of the coating and generating a corresponding control signal during at least a major portion of the deposition of a film of a film stack of the coating onto the substrate working surface; and

continually controlling at least one process variable of the coating deposition in response to the control signal during at least a major portion of the deposition of a film of a film stack of the coating onto the substrate working surface.

68. The method for vacuum deposition of thin film coatings onto a surface of a substrate in accordance with claim 67 wherein the process variable is controlled continuously during deposition of a film of a film stack of the coating.

69. The method for vacuum deposition of thin film coatings onto a surface of a substrate in accordance with claim 67 wherein the process variable is adjusted prior to commencing deposition of a subsequent film of a film stack of the coating in response to a measured value for a preceding film of the film stack, and the process variable is subjected to continuous closed loop control during deposition of the subsequent film in response to closed-loop.