Plasma source utilizing a macro-particle reduction coating and method of using a plasma source utilizing a macro-particle reduction coating for deposition of thin film coatings and modification of surfaces

Patent metadata

Field	Value
Publication number	US-2017338083-A1
Application number	US-201415532845-A
Country	US
Kind code	A1
Filing date	Dec 5, 2014
Priority date	Dec 5, 2014
Publication date	Nov 23, 2017
Grant date	—

Abstract

The present invention relates generally to a plasma source utilizing a macro-particle reduction coating and method of using a plasma source utilizing a macro-particle reduction for deposition of thin film coatings and modification of surfaces. More particularly, the present invention relates to a plasma source comprising one or more plasma-generating electrodes, wherein a macro-particle reduction coating is deposited on at least a portion of the plasma-generating surfaces of the one or more electrodes to shield the plasma-generating surfaces of the electrodes from erosion by the produced plasma and to resist the formation of particulate matter, thus enhancing the performance and extending the service life of the plasma source.

First claim

1 . A plasma source comprising:
a first electrode and a second electrode separated by a gas containing space, wherein a coating is deposited on at least a portion of each of the first electrode and the second electrode; a power source to which the first and second electrodes are electrically connected configured to supply a voltage that alternates between positive and negative to cause the voltage supplied to the first electrode to be out of phase with the voltage supplied to the second electrode and creating a current that flows between the electrodes; wherein the current creates a plasma between the electrodes that is substantially uniform over its length; wherein the first and second electrodes are shielded from contact with the plasma by the coating; and wherein the coating is resistant to forming particulate matter.

2 . The plasma source of claim 1 , wherein plasma is substantially uniform in its length in the substantial absence of closed circuit electron drift. cm 3 . The plasma source of claim 1 , wherein the plasma source is configured to deposit a coating using plasma enhanced chemical vapor deposition (PECVD).

4 . The plasma source of claim 1 , wherein the plasma source is provided with a power input greater than 20 kW per linear meter of plasma length.

5 . The plasma source of claim 4 , wherein the plasma source is provided with a power input greater than 40 kW per linear meter of plasma length.

6 . The plasma source of claim 1 , wherein the first electrode and the second electrode produce reduced particulate matter compared to uncoated electrodes.

7 . The plasma source of claim 1 , wherein the coating comprises a material having a low rate of sputtering.

8 . The plasma source of claim 1 , wherein the coating is substantially resistant to chemical reaction with the plasma.

9 . The plasma source of claim 1 , wherein the coating material has a resistivity less than 105 ohm cm.

10 . The plasma source of claim 9 , wherein the coating material has a resistivity less than 103 ohm cm.

11 . The plasma source of claim 1 , wherein the plasma comprises argon gas, and the rate of sputtering is less than 0.5 atoms per ion at 500 eV ion energies.

12 . The plasma source of claim 11 , wherein the rate of sputtering is less than 0.2 atoms per ion at 500 eV ion energies.

13 . The plasma source of claim 1 , wherein the coating comprises a material selected from the group consisting of boron, carbon, nickel, aluminum, silicon, transition metals, and combinations thereof.

14 . The plasma source of claim 1 wherein the coating comprises tungsten carbide.

15 . The plasma source of claim 1 , wherein the coating comprises chromium carbide.

16 . The plasma source of claim 1 , wherein the coating comprises boron carbide.

17 . The plasma source of claim 1 , wherein the coating comprises silicon carbide.

18 . The plasma source of claim 1 , wherein the coating comprises aluminum carbide.

19 . The plasma source of claim 1 , wherein the coating comprises indium oxide doped with tin.

20 . The plasma source of claim 1 , wherein the coating comprises a material selected from the group consisting of tungsten, chromium, titanium, molybdenum, and zirconium.

21 . The plasma source of claim 1 , wherein the coating comprises a metal alloy.

22 . The plasma source of claim 1 , wherein the coating comprises greater than 50 weight percent of one or more materials selected from the group consisting of cobalt, molybdenum, nickel, chromium, and alloys thereof.

23 . The plasma source of claim 1 , wherein the coating comprises a metal alloy selected from the group consisting of aluminum, silicon, nickel, chromium, and nickel-chromium.

24 . The plasma source of claim 1 , wherein the coating comprises a conductive ceramic material.

25 . The plasma source of claim 1 , wherein the coating has a sputter yield of less than 1 atom per ion when exposed to argon ions with energies of about 500 eV.

26 . The plasma source of claim 25 , wherein the coating has a sputter yield of less than 0.5 atoms per ion when exposed to argon ions with energies of about 500 eV.

27 . The plasma source of claim 1 , wherein the coating has a bond energy of greater than 12 ev per molecule.

28 . The plasma source of claim 1 , wherein the coating comprises a carbide selected from the group consisting of titanium carbide, zirconium carbide, hafnium carbide, chromium carbide, and tantalum carbide.

29 . The plasma source of claim 1 , wherein the first electrode and the second electrode form a first pair of electrodes, and the plasma source further comprises at least a third electrode and a fourth electrode forming a second pair of electrodes; wherein the first pair and the second pair of electrodes are disposed adjacently in an array.

30 . The plasma source of claim 29 , wherein the first electrode and the second electrode are each configured to produce a hollow cathode discharge.

31 . The plasma source of claim 29 , wherein the first, second, third, and fourth electrodes are each configured to produce a hollow cathode discharge.

32 . A method of forming a thin film coating on a substrate comprising using the plasma source of claim 1 to deposit the thin film coating on the substrate using plasma enhanced chemical vapor deposition.

33 . The method of claim 32 , wherein the coating stabilizes the voltage of the plasma source by preventing drift of the voltage for a predetermined duration of time during operation of the plasma source.

34 . The method of claim 33 , wherein the predetermined duration of time is greater than 100 hours.

35 . An electrode positioned in a plasma source device, comprising:
a first plasma-generating surface of the electrode; and a coating deposited on at least a portion of the first plasma-generating surface of the electrode; wherein the coating comprises a material having a resistivity less than 107 ohm cm; wherein the electrode is electrically connected to a power source for supplying a voltage that alternates between positive and negative, and is configured to generate a plasma proximate to the first plasma-generating surface of the electrode; and wherein the portion of the first plasma-generating surface on which the coating is deposited is shielded from contact with the plasma by the coating.

36 . The electrode of claim 35 , wherein the coating further comprises a binder.

37 . The electrode of claim 36 , wherein the binder comprises at least one of cobalt, nickel, and chromium.

38 . The electrode of claim 36 , wherein the binder comprises about 5-30 weight percent of the coating.

39 . The electrode of claim 35 , wherein the thickness of the coating is between 100 and 500 μm.

40 . The electrode of claim 39 , wherein the thickness of the coating is between 1 and 100 μm.

41 . The electrode of claim 35 , wherein the coating is resistant to sputtering by the plasma.

42 . The electrode of claim 35 , wherein the coating is deposited on at least a portion of the first plasma-generating surface of the electrode by a thermal spray coating process.

43 . T

Assignees

• Agc Flat Glass Na Inc
• Agc Glass Europe S A
• Asahi Glass Co Ltd

Inventors

• Chambers John
• Maschwitz Peter
• Lin Yuping
• Johnson Herb

Classifications

• H01J37/32559 Primary

  Protection means, e.g. coatings · CPC title

• H01J37/32596

  Hollow cathodes · CPC title

• H01J2237/3321

  CVD [Chemical Vapor Deposition] · CPC title

• C23C16/50

  using electric discharges {(generation and control of plasma in discharge tubes for surface treatment H01J37/32, H01J37/34)} · CPC title

• C03C2218/153

  by plasma-enhanced cvd · CPC title