Dual-Zone, Atmospheric-Pressure Plasma Reactor for Materials Processing
OwnerGary S. Selwyninventor
Life of this patent
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Abstract
A substrate is treated with a plasma by passing a gas through a first strong electrical field to form a plasma having active species and ionized species, passing at least a portion of said active species and ionized species into a second, weaker electrical field to generate a second but weaker plasma generation zone. Active species formed in said first plasma or said second plasma impinge onto the substrate to perform the desired treatment. The process allows a greater concentration of active species to reach the substrate than can be formed by the second plasma alone, while reducing arcing, maintaining a low gas temperature and providing other benefits.
Claims20
An apparatus for generating an atmospheric pressure or near-atmospheric pressure plasma and directing the plasma-generated active chemical species onto a substrate or workpiece, the apparatus comprising:
- a) a radio frequency electrode;
- b) a ground electrode spaced apart from the radio frequency electrode to form a first plasma generation zone between the radio frequency electrode and the ground electrode;
- c) an entrance for introducing gas into the first plasma generation zone;
- d) a radio frequency power supply connected between the radio frequency electrode and the ground electrode for generating a plasma in the first plasma generation zone;
- e) a second plasma generation zone that is proximate to, and in fluid communication with, the first plasma generation zone and the substrate and;
- f) means for transporting a gas through said first plasma generation zone, then through said second plasma generation zone and onto the substrate.
A process for treating a substrate with a plasma, comprising generating a plasma by passing a gas at atmospheric or near-atmospheric pressure through two or more plasma-generating zones, the first of which is not in direct contact with the substrate, the second of which is in contact with the first plasma generation zone and the substrate;
- the first plasma generation zone being operated in a “downstream” mode and the second plasma generation zone being operated in an “in-situ” mode.
An atmospheric-pressure plasma processing apparatus wherein the entrance for introducing gas into the plasma generation zone comprises an electrically-nonconducting, elongated gas distribution housing in fluid communication with a gas manifold and the plasma generation zone and sealed on all ends except the entrance to the plasma generation zone.
Dependencies are inferred from the claim text.