The atmospheric-pressure plasma jet: a review and comparison to other plasma sources

Abstract

Abstract-Atmospheric-pressure plasmas are used in a variety of materials processes. Traditional sources include transferred arcs, plasma torches, corona discharges, and dielectric barrier discharges. In arcs and torches, the electron and neutral temperatures exceed 3000 C and the densities of charge species range from 10 16 -10 19 cm 03 . Due to the high gas temperature, these plasmas are used primarily in metallurgy. Corona and dielectric barrier discharges produce nonequilibrium plasmas with gas temperatures between 50-400 C and densities of charged species typical of weakly ionized gases. However, since these discharges are nonuniform, their use in materials processing is limited. Recently, an atmospheric-pressure plasma jet has been developed, which exhibits many characteristics of a conventional, low-pressure glow discharge. In the jet, the gas temperature ranges from 25-200 C, charged-particle densities are 10 11 -10 12 cm 03 , and reactive species are present in high concentrations, i.e., 10-100 ppm. Since this source may be scaled to treat large areas, it could be used in applications which have been restricted to vacuum. In this paper, the physics and chemistry of the plasma jet and other atmospheric-pressure sources are reviewed.Index Terms-Atmospheric pressure, corona discharge, dielectric barrier discharge, plasma jet, plasma torch, thermal and nonthermal plasmas, transferred arc.

Chemical Composition of SiOx Films Deposited by an Atmospheric Pressure Plasma Jet (APPJ)

“…By increasing the OMCTS flow rate above 0.08 gÁh À1 , smooth and dense films are deposited already at minimal oxygen flow rates as indicated by a dominance of the longitudinal optical mode of SiO at 1 200 cm À1 (band III) along with a minimal content of single Si(ÀO) 1 constitution present in the film. These properties are conserved, if the ratio O 2 /OMCTS does not exceed the value 2.4.…”

“…The absorbance of band I increases with a decrease The constitution component Si(ÀO) 1 decreases with an increase in the relative absorbance of band III (Figure 4a). The decrease in the constitution component Si(ÀO) 2 correlates with the decrease in the absorbance of band II (Figure 4b).…”

“…Therefore, a broad range of applications exist: from protective layers against corrosion, over adhesion control to barriers against permeation of chemically reactive substances. [1][2][3] Compared to other non-equilibrium, normal pressure plasmas, jet configurations are considered advantageous in particular for local film deposition or for the coating of 3D forms e.g., inner walls of wells, trenches or cavities. Moreover, the jet geometry allows better flexibility in terms of substrate distance and electrical field, as the surfaces to be treated are not necessarily placed between electrodes.…”

Three modes in a radio frequency atmospheric pressure glow discharge

“…[1][2][3][4][5][6][7] These highly collisional plasmas share some important similarities with the classical low-pressure glow discharge. For example the spatial appearance of APGD is characteristically diffuse and free of streamers, 2 and their gas temperature can be reduced to near room temperature.…”

An Integrated Atmospheric Microwave Plasma Source

“…[1] Schütze et al [4] gives a comparison between different atmospheric-and low-pressure plasma sources. This source will be compared to other atmospheric plasma applications in an upcoming paper.…”