Evaluation of sample temperature and applied power on degradation of stearic acid in inductively coupled radio frequency plasma

Abstract

Plasma cleaning is a promising technology in surface treatments, despite technological interest its use is limited because its mechanisms still are not entirely understood. This work aims to evaluate how the applied power of an inductively coupled RF discharge at 13,56 MHz, with Ar and Ar+10%O 2 atmospheres, affects its capabilities to etch an organic molecule. Mass variation rate was used as direct characterization of degradation process and attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) was performed to search for residual molecular modifications. Additionally, optical emission spectroscopy (OES) measurements were performed to monitor the offer of active species in the gaseous volume. In experimental conditions was possible attain mass reduction from sample, with higher mass loss rate when applied power is increased. Material characterization shows the possibility of attain a high etch rate, while no structural modifications were detected, if the temperature is controlled.

Treatment of Glycine and Proline in Late Ar‐O2 Afterglow

“…Then, we demonstrated that phenyl rings of carbons in biphenyl molecules (C 12 H 10 ) can be opened by the singlet state O 2 (a 1 Δ g ) . More recently, treatments in direct plasmas were also considered …”

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

“…The present work is a complement of previous studies from MAFRA et al [18], BERNARDELLI et al [19], FARIAS et al [20] where the mechanisms of plasma degradation of organic molecules are studied. The set of experiments here presented aims to gain a better understanding in this issue, by investigating the differences on degradation of hexatriacontane in E or H modes, monitoring the by-products of the treatments.…”

Determination of Surface Temperature in ICP RF Plasma Treatments of Organic Materials

“…In cleaning and degradation plasma processes, where specific reactions of organic compounds depends on the temperature 10,11 , the correct analysis of this variable is very important. Previous works found that when stearic acid heats due to reactions with plasma, it melts and this leads to many undesirable effects, such as the formation of resistant compounds and boiling.…”

“…It has already been evidenced that in relatively high temperatures (313 K) 12,13 , even when the material begins in the solid state, functionalization reactions becomes more important than degradation, leading to polymerization processes. On the other hand, treatments at lower temperatures (273 K) lead to high mass loss, where the possible by-products of functionalization are removed in degradation processes 10 . On most studies of plasma degradation, the temperature measurement was obtained by a thermocouple, which is placed into the sample holder or into the sample itself.…”