RF frequency effects on molecular fragmentation

Abstract

The chlorine contents of 40 kHz and 13.56 MHz RF silicontetrachloride and dichlorosilane plasmas were investigated using actinometric evaluation in a parallel-plate (stainless-steel disk electrodes, stainless-steel reactor) electrode and in an electrodeless (external electrodes and glass reactor) discharges, in the 50-500 W RF power and 100-500 mTorr pressure ranges. It was found that the frequency has a significant effect on the molecular fragmentation of dichlorosilane and a less important effect on the fragmentation of silicontetrachloride. This behaviour was related to the molecular structures of the two starting components. The plasma-induced surface chemistries and morphology changes were also investigated and related to the different chemistries driven under 40 kHz and 13.56 MHz frequency environments. Plasma-induced and frequency-controlled molecular fragmentation reactions can be envisaged based on these findings.

Synthesis and Surface Functionalization under Cold-plasma Conditions.

“…The concentration of free chlorine in a DS-plasma is much higher at the low RF frequency range of 40-500 kHz in comparison to 13.56 MHz RF frequency. This is in agreement with results presented by Flamm [29] indicating that important changes are induced when the discharge frequency crosses the basic ion-plasma frequency.…”

Tuning the electrical property via defect engineering of single layer MoS2 by oxygen plasma

“…During the plasma process, the etching rate depends on the oxygen concentration, rf power, frequency and plasma exposure time. 30,31 The previous experiments used high power reactive ion etcher while we used a O 2 :Ar mixture of 20:80, moderately low power and low frequency plasma for short duration.…”

Surface functionalization by RF plasma deposition of ethylene diamine, acrylonitrile, and acetonitrile

“…Higher RF excitation frequency provides efficient dissociation of the gas, which forms plasma consisting of high ion flux and low ion energies. 32 The films so obtained by AN plasma had similar differences in compositions. But frequency had almost no effect on the plasma polymerization of AcN.…”