Dependence of E-H transition in argon ICP discharges for treatment of organic molecules

Abstract

Plasma surface cleaning is an alternative process that aims at the fully removal of organic contaminants on several kinds of materials. Despite its advantages, there are still lacks on the comprehension of the complex relations between plasma-generated species and organic molecules during plasma cleaning. In the present work, a linear alkane (hexatriacontane -C 36 H 74 ), used as a contaminant model, was exposed to an Argon radiofrequency (RF) inductively coupled plasma (ICP). The by-products from degradation were monitored by optical emission spectroscopy (OES) and residual gas analysis (RGA), to identify the influence of sample positioning on E and H discharge modes regions. The exposition to H-mode discharge resulted in more intense and profuse emissions of C-H and C 2 systems. RGA results show similar byproducts from degradation in both modes; however, the intensity from treatment in H-mode is largely greater. It was also observed that plasma etching in H-mode is enough to melt the sample, while E-type discharge leaves the surface of the sample apparently unchanged.

Influence of applied plasma power on degradation of L-proline in an inductively coupled RF plasma reactor

“…The higher degradation of the samples with the increase of the power is related to the greater density of the species chemically active in the plasma, ions and electrons. The temperature of the sample is another factor that should contribute significantly to a greater degradation with power increase [2,5,21,22,37]. Because of that, in the present work, a water circulation system was used to keep the temperature constant at about 0°C.…”

“…However, due to the complexity of the plasma environment, it is necessary to obtain more information about the influence of the different species on the degradation of organic functions [19]. In addition, it is also important to study the structural changes of the treated material generated by the physical parameters of the discharge, both in organic [20][21][22] and in metallic materials [23].…”

Influence of the pressure on the interaction between stearic acid and Ar-O2 in inductively coupled radio frequency plasma

“…Molecules widely used as models for surface contaminants are stearic acid and hexatriacontane. Works carried out with these compounds [12][13][14][17][18][19][20][21][22] evaluated the influence of the types of discharge and process parameters such as gas composition, pressure, power, and frequency of the electrical source.…”