초록 ▼

Large area atmospheric-pressure plasma jet. A plasma discharge that can be operated at atmospheric pressure and near room temperature using 13.56 MHz rf power is described. Unlike plasma torches, the discharge produces a gas-phase effluent no hotter than 250.degree. C. at an applied power of about 3

Large area atmospheric-pressure plasma jet. A plasma discharge that can be operated at atmospheric pressure and near room temperature using 13.56 MHz rf power is described. Unlike plasma torches, the discharge produces a gas-phase effluent no hotter than 250.degree. C. at an applied power of about 300 W, and shows distinct non-thermal characteristics. In the simplest design, two planar, parallel electrodes are employed to generate a plasma in the volume therebetween. A "jet" of long-lived metastable and reactive species that are capable of rapidly cleaning or etching metals and other materials is generated which extends up to 8 in. beyond the open end of the electrodes. Films and coatings may also be removed by these species. Arcing is prevented in the apparatus by using gas mixtures containing He, which limits ionization, by using high flow velocities, and by properly spacing the rf-powered electrode. Because of the atmospheric pressure operation, there is a negligible density of ions surviving for a sufficiently long distance beyond the active plasma discharge to bombard a workpiece, unlike the situation for low-pressure plasma sources and conventional plasma processing methods.

대표청구항 ▼

[ What is claimed is:] [1.]1. An apparatus for generating a gaseous jet containing concentrations of reactive species from an atmospheric pressure plasma discharge which comprises in combination:(a) a chamber having a planar, grounded electrically conducting wall, a closed end and an open end;(b) a

[ What is claimed is:] [1.]1. An apparatus for generating a gaseous jet containing concentrations of reactive species from an atmospheric pressure plasma discharge which comprises in combination:(a) a chamber having a planar, grounded electrically conducting wall, a closed end and an open end;(b) a planar, conducting electrode located within said chamber disposed such that said planar electrode is spaced apart from and parallel to the planar, grounded electrically conducting wall of said chamber, thereby defining a volume;(c) means for flowing gases through the volume; and(d) means for supplying rf energy to said planar electrode such that an homogeneous, continuous plasma discharge occurs between said planar electrode and said planar, grounded electrically conducting wall of said chamber, whereby the gaseous products of the plasma discharge exit through the open end of said chamber at ambient pressure.