K Tachibana et al 1984 J. Phys. D: Appl. Phys. 17 1727 doi:10.1088/0022-3727/17/8/026
K Tachibana, M Nishida, H Harima and Y Urano
Show affiliationsIn an RF-discharge methane plasma, the dissociation rate of CH4 in collisions with electrons has been measured using a laser absorption technique. The measured rate increases as the RF power increases and as the gas pressure decreases. The electron energy distribution function f( epsilon ) and the electron density ne have also been measured by a heated electrical probe. The measured f( epsilon ) is quite different from the Maxwellian distribution and rather close to the Druyvesteynian distribution. The dissociation rate constant deduced from f( epsilon ) and the reported cross-section when multiplied by the measured ne is consistent with the results of the laser absorption method. Based on these measurements a modelling of the plasma has been performed using a set of rate equations for CH4 and the various neutral and ionic species produced in the plasma. The calculated degree of dissociation for CH4 in the plasma agrees well with the measured results. The most abundant neutral radical in the plasma predicted by the model is CH3, while CH5+ is the most abundant ionic species.
52.70.Gw Radio-frequency and microwave measurements
52.80.Pi High-frequency and RF discharges
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, etc.)
52.70.Ds Electric and magnetic measurements
82.20.Pm Rate constants, reaction cross sections, and activation energies
82.30.Lp Decomposition reactions (pyrolysis, dissociation, and fragmentation)
Instrumentation and measurement
Issue 8 (14 August 1984)
K Tachibana et al 1984 J. Phys. D: Appl. Phys. 17 1727
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