H₂Partial Pressure Dependences of CH₃Radical Density and Effects of H₂Dilution on Carbon Thin-Film Formation in RF Discharge CH₄Plasma

Abstract

Both the CH3 radical density and carbon thin-film formation were investigated in an RF-discharge CH4/H2 plasma. In this plasma, although CH3 radical density was almost constant, the deposition rate decreased markedly with increasing H2 partial pressure. These results suggested that the surface loss of the radicals was decreased due to the change in surface composition of the film, and also the film etching was enhanced with increasing H2 partial pressure. Therefore, the deposition rate of the carbon thin film decreased.

Application of mid-infrared tuneable diode laser absorption spectroscopy to plasma diagnostics: a review

“…Recently, a study has reported on the fundamental bands of the 10 B and 11 B isotopomers of BO in their ground 2 + states, detected in natural abundance in the O + BCl 3 reaction, at Doppler limited resolution using tuneable diode laser absorption spectroscopy. It extended a preliminary study reported earlier, in which only the spectrum of 11 BO was examined quantitatively [120]. The radicals were made in a 1 m long White-type absorption cell with 26 passes, following the method described by Clyne et al and Llewellyn et al [121,122].…”

“…investigating the influence of rare gases on the plasma. They have also combined IR absorption with emission spectroscopy and investigated the effect of water vapour on the methyl radical concentration in argon/methane and argon/methanol RF plasmas using TDLAS [17,18,[41][42][43]. Kim…”

“…TDLAS is increasingly being used in the spectral region between 3 and 20 µm for measuring the concentrations of free radicals, transient molecules and stable products in their electronic ground states. TDLAS can also be used to measure neutral gas temperatures [9] and to investigate dissociation processes of molecular low temperature plasmas [10][11][12][13]. The main applications of TDLAS until now have been for investigating molecules and radicals in fluorocarbon etching plasmas [9,12,14] and in plasmas containing hydrocarbons [13,[15][16][17][18][19][20][21].…”

Absorption spectroscopic studies of carbon dioxide conversion in a low pressure glow discharge using tunable infrared diode lasers

“…Tunable diode laser absorption spectroscopy (TDLAS) in the mid-infrared spectral region between 3 and 20 µm is a non-invasive technique for measuring number densities of stable molecules and radicals. TDLAS can also be used to determine neutral gas temperatures [1] and to investigate dissociation processes [2][3][4][5]. Due to their small laser line width (about 10 −4 cm −1 ) the lead-salt diode lasers used in the mid-infrared region are well suited for high resolution spectroscopy purposes, e.g.…”

Kinetic and Diagnostic Studies of Molecular Plasmas Using Laser Absorption Techniques

“…TDLAS is increasingly being used in the spectral region between 3 and 20 µm for measuring the concentrations of free radicals, transient molecules and stable products in their electronic ground states. TDLAS can also be used to measure neutral gas temperatures [2] and to investigate dissociation processes of molecular low temperature plasmas [3][4][5][6]. The main applications of TDLAS until now have been for investigating molecules and radicals in fluorocarbon etching plasmas [2,5,7], in plasmas containing hydrocarbons [6, 8-14, 60,63] and nitrogen, hydrogen and oxygen [58,59,61,62].…”