Plasma source and method for removing materials from substrates utilizing pressure waves

An atmospheric pressure plasma source, comprising:

• a plasma-generating chamber configured for generating atmospheric pressure, non-thermal plasma, having a connector for a gas supply configured for feeding a gas to the plasma-generating chamber, and having within a plasma-generating region;
• a dielectric structure located against a grounded interior wall of the plasma-generating chamber, the dielectric structure spanning laterally across the plasma-generating chamber from one side of the plasma-generating chamber to another side of the plasma-generating chamber, and the dielectric structure having a passage formed therein which extends through an entire body of the dielectric structure and through which the gas passes;
• a powered electrode made through the body of the dielectric structure and extending outside the body of the dielectric structure partially into the plasma-generating region of the plasma generating chamber, the plasma-generating region is beside the dielectric structure through which the gas passes, and the electrode is coupled to a power source configured to provide power to the atmospheric pressure, non-thermal plasma;
• a plasma outlet downstream from the electrode, communicating with the plasma-generating chamber, and out-letting the plasma to outside the chamber;
• and
• the atmospheric pressure, non-thermal plasma out-letted from the plasma outlet comprising an atmospheric pressure, non-thermal plasma plume comprising energetic plasma species emitted from the plasma outlet at a supersonic velocity into an ambient environment outside the atmospheric pressure plasma source,
• wherein, with the power source powering the atmospheric pressure, non-thermal plasma, the plasma plume outside the atmospheric pressure plasma source comprises periodic regions of pressure waves of high plasma density and low plasma density extending from the plasma outlet to a substrate having material thereon for removal, and
• wherein the regions of high plasma density outside the atmospheric pressure plasma source comprise shockwaves effective for enhancing removal of the material from the substrate with which the plasma plume having the periodic regions of high plasma density and low plasma density interacts.