METHOD AND APPARATUS FOR GENERATING HIGHLY REPETITIVE PULSED PLASMAS

• US 20170311431A1
• Filed: 07/12/2017
• Published: 10/26/2017
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: PlasmaNano Corp.
• Original Assignee: PlasmaNano Corp.
• Inventors: Park, Jaeyoung
• Granted Patent: US 11,427,913 B2
• Time in Patent Office: Days
• CPC Class Codes: C23C 16/0245 by etching with a plasma
• CPC Class Codes: C23C 16/452 by activating reactive gas streams before their introduction into the reaction chamber, e.g. by ionisation or addition of reactive species
• CPC Class Codes: C23C 16/453 passing the reaction gases through burners or torches, e.g. atmospheric pressure CVD C23C16/513 takes precedence; for flame or plasma spraying of coating material in the molten state C23C4/00
• CPC Class Codes: C23C 16/45557 Pulsed pressure or control pressure
• CPC Class Codes: C23C 16/505 using radio frequency discharges
• CPC Class Codes: C23C 16/515 using pulsed discharges
• CPC Class Codes: H01J 37/32082 Radio frequency generated discharge H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01J 37/3211 Antennas, e.g. particular shapes of coils
• CPC Class Codes: H01J 37/32146 Amplitude modulation, includes pulsing
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H05H 1/46 using applied electromagnetic fields, e.g. high frequency or microwave energy H05H1/26 takes precedence
• CPC Class Codes: H05H 1/4652 using inductive coupling means, e.g. coils
• CPC Class Codes: H05H 2242/24 Radiofrequency or microwave generators

Abstract

A pulsed radio frequency inductive plasma source and method are provided. The source may generate plasma at gas pressures from 1 torr to 2000 torr. By utilizing high power RF generation from fast solid state switches such as Insulated-Gate Bipolar Transistor (IGBT) combined with the resonance circuit, large inductive voltages can be applied to RF antennas to allow rapid gas breakdown from 1-100 μs. After initial breakdown, the same set of switches or an additional rf pulsed power systems are utilized to deliver large amount of rf power, between 10 kW to 10 MW, to the plasmas during the pulse duration of 10 μs-10 ms. In addition, several methods and apparatus for controlling the pulse power delivery, timing gas and materials supply, constructing reactor and substrate structure, and operating pumping system and plasma activated reactive materials delivery system will be disclosed. When combined with the pulsed plasma generation, these apparatuses and the methods can greatly improve the applicability and the efficacy of the industrial plasma processing.

Claims

1. A method for generating plasma in a reactor chamber that contains a carrier gas and one or more reactive precursors with a pressure of between 1 torr and 2,000 torr, the method comprising:

generating, by a pulsed radio frequency source that is driven with a pulse duration that is less than 10 ms, a pulsed radio frequency signal having a radio frequency is less than 10 MHz;

delivering the pulsed radio frequency signal to an inductive antenna coupled to the pulsed radio frequency source and surrounding the reactor chamber;

initiating, by the pulsed radio frequency signal delivered to the inductive antenna, a breakdown of the carrier gas and one or more reactive precursors in the reactor chamber to generate a plasma; and

generating a plasma in the reactor chamber by the breakdown of the carrier gas and one or more reactive precursors in the reactor chamber.

2. The method of claim 1, wherein generating the pulsed radio frequency signal further comprises generating the pulsed radio frequency signal with a pulse duration that is greater than 10 μ

s.

3. The method of claim 1, wherein generating the pulsed radio frequency signal further comprises generating the pulsed radio frequency signal with a pulse duration that is between 10 μ

s and 10 ms.

4. The method of claim 1 further comprising changing, by the pulsed radio frequency source, its frequency after initiation of the plasma.

5. The method of claim 1 further comprising generating, by a second pulsed radio frequency source, a second pulsed radio frequency signal and sustaining, by an inductive antenna coupled to the second pulsed radio frequency source, the plasma by the second pulsed radio frequency signal.

6. The method of claim 1 further comprising providing, by an inlet system, the carrier gases and the one or more reactive precursors into the reactor chamber in a repetitively pulsed manner with the duty factor between 1% and 100%.

7. The method of claim 1 further comprising maintaining, by a pumping system, a pressure in the reactor chamber in a repetitively pulsed manner with the duty factor between 1% and 100%.

8. The method of claim 1 further comprising collecting, by a material collection system, materials formed in the reactor chamber.

9. The method of claim 1 further comprising treating target materials using the one or more reactive precursors that are activated by the plasma.

10. The method of claim 9, wherein one or more reactive precursor materials are in one of a gaseous phase, a liquid phase or a solid phase.

11. The method of claim 9, wherein one or more reactive precursor materials is one of a reactive gas containing hydrogen, oxygen, nitrogen, fluorine, chlorine, sulfur, phosphor and hydrocarbon.

12. The method of claim 9, wherein one or more reactive precursor materials are acids, bases, polymers, metals, ceramics, and composite materials.

13. A method for generating plasma in a reactor chamber that contains a carrier gas and one or more reactive precursors with a pressure of between 1 torr and 2,000 torr, the method comprising:

generating, by a pulsed radio frequency source that is driven with a pulse duration that is less than 10 ms, a pulsed radio frequency signal having a radio frequency is less than 10 MHz;

delivering the pulsed radio frequency signal to an inductive antenna coupled to the pulsed radio frequency source and surrounding the reactor chamber;

initiating, by the pulsed radio frequency signal delivered to the inductive antenna, a breakdown of the carrier gas and one or more reactive precursors in the reactor chamber to generate a plasma;

generating a plasma in the reactor chamber by the breakdown of the carrier gas and one or more reactive precursors in the reactor chamber; and

exhausting, by a material exhaust system connected to the reactor chamber, the material flow from one or more activated reactive precursors out of the reactor chamber.

14. The method of claim 13, wherein exhausting the material flow further comprises exhausting the material flow from one or more activated reactive precursors out of the reactor chamber in a repetitively pulsed manner with a duty factor between 1% and 99% and with a repetition frequency between 1 Hz and 100 Hz.

15. The method of claim 13 further comprising maintaining, by a pumping system, a pressure in the reactor chamber in a repetitively pulsed manner with the duty factor between 1% and 100%.

16. The method of claim 13 further comprising providing, by an inlet system, the carrier gases and the one or more reactive precursors into the reactor chamber in a repetitively pulsed manner with the duty factor between 1% and 100%.

17. The method of claim 13 further comprising directing, using a nozzle, a flow of one or more reactive precursors onto a target surface located outside the reactor chamber in an ambient pressure so that the target surface and the one or more reactive precursors are activated by the plasma when the target surface is in the reactor chamber.