Apparatus and method for nano plasma deposition

• US 20080095952A1
• Filed: 01/23/2007
• Published: 04/24/2008
• Est. Priority Date: 10/18/2006
• Status: Active Grant

• Current Assignee: Surfatek LLC
• Original Assignee: Metascape LLC
• Inventors: Storey, Daniel M.
• Granted Patent: US 7,920,369 B2
• Time in Patent Office: Days
• US Class Current: 427/569
• CPC Class Codes: C23C 14/185 by cathodic sputtering
• CPC Class Codes: C23C 14/325 Electric arc evaporation
• CPC Class Codes: H01J 37/32055 Arc discharge
• CPC Class Codes: H01J 37/32064 Circuits specially adapted for controlling the arc discharge for plasma torches H01H1/36

Abstract

An apparatus and method for initiation and control of a sustained metal plasma and nano plasma (macroparticulate) deposition methods for preparing modified metal coatings are provided. The plasma deposition process can be tightly controlled by virtue of a device that incorporates a plasma arc initiator component and an internal power supply that is capable of controlling dwell time on the target and the size range of particles ejected in the plasma arc.

Claims

1. A plasma arc initiator device, comprising:

a solid state relay;

a power supply having a positive side coupled to a first end of the solid state relay;

a resistor having a first end coupled to a second end of the solid state relay;

a second end of the resistor coupled to a negative side of the power supply; and

a cathode formed at the negative side of the power supply.

2. The plasma arc initiator device of claim 1, further comprising an anode formed at the positive side of the power supply and separated a predetermined distance from the cathode.

3. The plasma arc initiator device of claim 1, wherein the cathode provides a point of contact on a target.

4. The plasma arc initiator device of claim 3, wherein the point of contact consists of one or more conductive materials.

5. The plasma arc initiator device of claim 1, further comprising:

a material having a resistance, wherein the material has a first end coupled to the positive side of the power supply and a second end coupled to the negative side of the power supply.

6. The plasma arc initiator device of claim 5, wherein the resistance of the material is slightly greater than or equal to a resistance of plasma formed between the cathode and an anode formed at the positive side of the power supply and separated a predetermined distance from the cathode.

7. The plasma arc initiator device of claim 1, wherein the power supply comprises:

at least one Insulated Gate Bipolar Transistor (IGBT), wherein a collector of the at least one IGBT is coupled to the positive side, wherein an emitter of the at least one IGBT is coupled to the negative side;

a DC power supply coupled to the collector of the at least one IGBT; and

at least one control circuit, wherein one of the at least one control circuit is coupled to a gate of the at least one IGBT.

8. The plasma arc initiator device of claim 1, wherein the power supply comprises:

at least one semiconductor relay (SCR), wherein a first input of the at least one SCR is coupled to the positive side, wherein an output of the at least one SCR is coupled to the negative side;

a DC power supply coupled to the first input of the at least one SCR; and

at least one control circuit, wherein one of the at least one control circuit is coupled to a second input of the at least one SCR.

9. A power supply control unit, comprising:

at least one Insulated Gate Bipolar Transistor (IGBT), wherein a collector of the at least one IGBT is coupled to a DC power supply and an emitter of the at least one IGBT is coupled to an output; and

at least one control circuit, wherein one of the at least one control circuit is coupled to a gate of the at least one IGBT.

10. The power supply control unit of claim 9, further comprising:

a cold plate coupled with a respective one of the at least one IGBT.

11. The power supply control unit of claim 9, wherein the DC power supply is capable of supplying a current up to 600 A and a DC voltage up to 20 V.

12. The power supply control unit of claim 9, wherein the at least one control circuit is a single control circuit coupled to all of the at least one IGBT.

13. The power supply control unit of claim 9, wherein each of the at least one control circuit is coupled to a corresponding one of the at least one IGBT.

14. A method for plasma deposition, comprising:

providing a target and a substrate in a chamber;

contacting the target with a cathode of a plasma initiator having a power supply control unit;

initiating a plasma arc at the target using the plasma initiator;

depositing target material evaporated from the target by the plasma arc on the substrate; and

controlling a dwell time by monitoring the plasma arc speed using the power supply control unit.

15. The method of claim 14, further comprising:

supplying current to different power taps using the power supply control unit, wherein the power taps are connected to various input connections on the target;

depositing the target material evenly on the substrate by switching power from one tap to another; and

monitoring and controlling a power draw of the power supply control unit.

16. The method of claim 15, wherein the switching of the power from one tap to another is in a predetermined pattern, a chaotic pattern, or a square wave pattern with very little overlap.

17. The method of claim 14, wherein the plasma initiator comprises:

a solid state relay;

the power supply control unit having a positive side coupled to a first end of the solid state relay;

a resistor having a first end coupled to a second end of the solid state relay;

a second end of the resistor coupled to a negative side of the power supply control unit; and

a cathode formed at the negative side of the power supply control unit, wherein the cathode provides a point of contact on a target.

18. The method of claim 14, wherein the power supply control unit comprises:

at least one Insulated Gate Bipolar Transistor (IGBT), wherein a collector of the at least one IGBT is coupled to a DC power supply and an emitter of the at least one IGBT is coupled to an output; and

at least one control circuit, wherein one of the at least one control circuit is coupled to a gate of the at least one IGBT.

19. The method of claim 14, further comprising:

controlling nanoparticle production by configuring the target to produce a desired size and/or number of particles.

20. The method of claim 19, wherein the target is configured to have a concave surface, a convex surface, or a flat surface.

21. The method of claim 20, wherein the target is further configured to have a pattern of diamonds or a pyramid pattern.

22. A method for controlling nanoparticle production, comprising:

providing a target configured to produce a desired size and/or number of particles.

23. The method of claim 22, wherein the target comprises a concave surface, a convex surface, or a flat surface.

24. The method of claim 23, wherein the target further comprises a pattern of diamonds or a pyramid pattern.

25. The method of claim 24, wherein the target has the pattern of diamonds, wherein the diamonds have a height of between about ¼

inch and about ¾

inch and an angle normal to the surface of about between 20° and

60°

to produce a large number of large nanoparticles.

26. The method of claim 24, wherein the target has the pyramid pattern, wherein the pyramid pattern has an angle of the sides at 60°

to the normal, and a length of one side of the base of the pyramid is 0.5 inch.