Influence of the excitation frequency on CH₄/H/H₂plasmas for diamond film deposition: electron energy distribution function and atomic hydrogen concentration

Abstract

The influence of the excitation frequency f = ω/2π of the applied electric field on the period average electron energy distribution function (EEDF) and on the atomic hydrogen concentration found near the deposited diamond films (substrate) and in the bulk of CH 4 ( 5%)/H/H 2 plasmas produced in RF and MW discharges is estimated. This is done through the solution, as a function of the reduced effective electric field, of a stationary homogeneous electron Boltzmann equation (EBE) and the solution, in terms of the atomic hydrogen mole fraction, of a simple kinetic model for the plasma mechanisms underlying the production and loss of atomic hydrogen. The physical basics underlying the approach followed to solve the EBE, including discussion of EEDF time-modulation effects, are discussed in the light of recent results by Loureiro (1993 Phys. Rev. E 47 1262) on time-dependent kinetics of pure H 2 plasmas. Correlations are established between the results, obtained under various discharge conditions, from plasma-enhanced chemical vapour deposition (PECVD) experiments of diamond-like carbon (DLC) and diamond thin films, and the calculated EEDF, atomic hydrogen concentrations (in the plasma and near the substrate) and mechanisms underlying the production and loss of atomic hydrogen in the plasma.

Microwave plasma annealing of sol-gel deposited tantalum oxide and zinc oxide films

“…Microwave plasma processes have received a great deal of attention in the materials community. Their relevance is mostly outlined in its use in the chemical vapor deposition of diamond, diamond like carbon [14] and many other materials thin films [15], favored by electron cyclotron resonant configurations [16]. They have additionally been also used as a post processing tool to etch materials in reactive ion etching processes [17] and as a sterilization tool of chirurgical instruments [18].…”

Hybrid simulation of a dc-enhanced radio-frequency capacitive discharge in hydrogen

“…It was found that H 2 has an important effect on the charged particle density and the EEDF. Gordillo-Vázquez et al [63] analysed the influence of the excitation frequency of the applied electric field on the EEDF and H-atom concentration near the deposited diamond films (substrate) and in the bulk of CH 4 ( 5%)/H/H 2 plasmas produced in RF and MW discharges through the solution of a stationary homogeneous electron Boltzmann equation and the solution of a kinetic model for the production and loss of H atoms. Hassouni et al [64] reviewed modelling issues related to the design of MW cavity for diamond deposition that make use of hydrogen-methane plasmas and to the prediction of active species densities at the growing substrate surface.…”

Low‐Pressure PECVD of Nanoparticles in Carbon Thin Films from Ar/H2/C2H2 Plasmas: Synthesis of Films and Analysis of the Electron Energy Distribution Function

“…However, the temporal behavior of the EEDF in low pressure RF-produced C 2 H 2 /H 2 /Ar plasmas has not been reported. In this regard, only the stationary or period-average Boltzmann equation has been solved for studying the kinetics of RF and/or MW plasmas containing hydrocarbon precursors, such as H 2 /H/ CH 4 [3,22,23] and H 2 /Ar/C 2 H 2 , [9,24] giving results of interest for the synthesis by PECVD of films with various kinds of carbon-based nanostructures. Here we have tried to link the EEDF simulation with properties of deposited films by using various values of electric fields associated with the range of particle diameters observed within the films.…”