Coaxial hollow cathode plasma assisted directed vapor deposition and related method thereof

Patent metadata

Field	Value
Publication number	US-9640369-B2
Application number	US-201013202828-A
Country	US
Kind code	B2
Filing date	Feb 24, 2010
Priority date	Feb 24, 2009
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

A plasma generation process that is more optimized for vapor deposition processes in general, and particularly for directed vapor deposition processing. The features of such an approach enables a robust and reliable coaxial plasma capability in which the plasma jet is coaxial with the vapor plume, rather than the orthogonal configuration creating the previous disadvantages. In this way, the previous deformation of the vapor gas jet by the work gas stream of the hollow cathode pipe can be avoided and the carrier gas consumption needed for shaping the vapor plume can be significantly decreased.

First claim

We claim:

1. An apparatus for applying at least one coating onto at least one substrate, said apparatus comprising:
a deposition chamber,
at least one evaporant source,
at least one energetic beam for impinging said evaporant source forming a vapor plume,
at least two hollow cathodes aligned at least substantially coaxially with said at least one evaporant source for delivering a discharge current, and wherein said apparatus is configured wherein said at least one evaporant source is disposed outside said at least two hollow cathodes,
at least one plasma-forming gas emitted from each of said at least two hollow cathodes,
at least one anode for electrostatically attracting said discharge current from at least one of said two hollow cathodes, and
wherein a) said plasma jet at least partially shapes said vapor plume b) said plasma jet at least partially entrains said vapor plume and at least partially assists in transporting said vapor plume to said substrate to provide said at least one coating onto said substrate.

2. The apparatus of claim 1 , wherein said at least one evaporant source is a solid.

3. The apparatus of claim 1 , wherein said plasma forming gas forms a plasma jet streaming off of an orifice of each of said at least two hollow cathodes.

4. The apparatus of claim 3 , wherein the axis and/or momentum of said plasma jet and of said energetic beam are at least substantially aligned with that of each of said at least two hollow cathodes.

5. The apparatus of claim 1 , wherein at least some of said vapor plume is ionized by said plasma jet and by said energetic beam.

6. The apparatus of claim 1 , further comprising means for initiating said hollow cathode plasma emission.

7. The apparatus of claim 6 , wherein said means comprise a heat source based on Ohmic heating of a current conductor, an auxiliary gas discharge, or a kicker circuit to ignite the hollow cathode emission via a high-voltage impulse.

8. The apparatus of claim 1 , further comprising at least one cooling device for cooling said at least one evaporant source.

9. The apparatus of claim 8 , where said cooling device comprises a crucible.

10. The apparatus of claim 1 , wherein said at least two hollow cathodes are positioned in an annular configuration around said at least one evaporant source with the evaporant source at least substantially coaxially integrated inside said annular configuration.

11. The apparatus of claim 10 , wherein relative intensity of the plasma jets generated by said at least one of said at least two hollow cathodes may be controlled for directional sweeping either of said plasma jet or vapor plume, or both, from side to side.

12. The apparatus of claim 11 , wherein said directional sweeping is accomplished by controlling the pressure or gas flow rate individually in each hollow cathode.

13. The apparatus of claim 10 , wherein said annular configuration provides an array.

14. The apparatus of claim 1 , wherein said energetic beam is produced by an electron beam gun or a laser source.

15. The apparatus of claim 14 , wherein said energetic beam source further comprises means to alter the beam impingement points among one or more evaporation sources.

16. The apparatus of claim 1 , further comprising a bias voltage applied to said substrate for accelerating ions toward said substrate.

17. The apparatus claim 16 , wherein said bias voltage is a DC, AC or pulsed voltage.

18. The apparatus of claim 1 , further comprising an inlet for emitting at least one secondary gas forming at least one jet positioned at least substantially coaxially with said at least one evaporant source and at least one of said at least two hollow cathodes.

19. The apparatus of claim 18 , wherein said at least one secondary gas jets at least partially assist in shaping and transporting said vapor plume to said substrate.

20. The apparatus of claim 18 , wherein said secondary gas jets introduce reactant gases for creating compounds with the vapor plume.

21. The apparatus of claim 1 , wherein said anode is configured in an elevated position above said at least two hollow cathodes.

22. The apparatus of claim 21 , wherein said anode is positioned above said substrate.

23. The apparatus of claim 21 , wherein said anode is positioned between said substrate and said at least two hollow cathodes.

24. The apparatus of claim 23 , wherein said anode is annular.

25. The apparatus of claim 24 , wherein said anode further comprises means for creating a magnetic field and for guiding a magnetic flux such that the magnetic field lines in front of the anode are substantially parallel to its surface and radially directed thus forming a closed electrons drift track in circumferential direction which is substantially parallel to the anode's surface.

26. The apparatus of claim 25 , wherein said magnetic field facilitates an axial potential gradient for accelerating positive ions toward said substrate.

27. The apparatus of claim 25 , wherein said means for creating a magnetic field and for guiding a magnetic flux comprises a magnetic circuit in communication with said anode.

28. The apparatus of claim 1 , wherein said anode is annular and positioned at least substantially coaxially and in the same plane as the at least one hollow cathode.

29. The apparatus of claim 28 , wherein said anode is bisected radially to form anode segments.

30. The apparatus of claim 29 , wherein said anode is bisected into the same number of segments as the number of hollow cathodes and the hollow cathode emissions burn diametrically across the vapor plume between each one of the hollow cathodes and the corresponding anode segment situated at the opposite position.

31. The apparatus of claim 1 , further comprising a solenoid positioned coaxially and at least partially proximal to at least one of said at least two hollow cathodes.

32. The apparatus of claim 31 , wherein said solenoid is capable of at least partially bending said energetic beam.

33. The apparatus of claim 31 , wherein said solenoid is positioned and energized such as to magnetically enhance the at least one of said hollow cathode's efficiency.

34. The apparatus of claim 31 , wherein said solenoid at least partially increases plasma density and facilitates an axial potential gradient for accelerating positive ions toward said substrate.

35. The apparatus of claim 1 , wherein said at least two hollow cathodes comprises at least one of the following: pipe, conduit, tube, channel, hose, stem, duct, port, groove, passage, tunnel, and port.

36. An apparatus for applying at least one coating onto at least one substrate, said apparatus comprising:
a deposition chamber,
at least one evaporant source,
at least one energetic beam for impinging said evaporant source forming a vapor plume,
at least one hollow cathode aligned at least substantially coaxially with said at least one evaporant source for delivering a discharge current, and wherein said apparatus is configured wherein said at least one evaporant source is disposed outside said at least one hollow cathode,
at least one plasma-forming gas emitted from said hollow cathode,
at least one anode for electrostatically attracting said discharge current from said hollow catho

Assignees

• Wadley Haydn N G
• Mattausch Goesta
• Morgner Henry
• Roegner Frank-Holm
• Univ Virginia Patent Foundation

Inventors

• Wadley Haydn N G
• Mattausch Goesta
• Morgner Henry
• Roegner Frank-Holm

Classifications

• H01J37/32339

  using electromagnetic radiation · CPC title

• H01J2237/332

  Coating · CPC title

• H01J37/3244

  Gas supply means · CPC title

• H01J37/32357

  Generation remote from the workpiece, e.g. down-stream · CPC title

• C23C14/32

  by explosion; by evaporation and subsequent ionisation of the vapours {, e.g. ion-plating}(C23C14/34 - C23C14/48 take precedence) · CPC title