Transport parameters of F ⁻ ions in Ar/BF ₃ mixtures

Abstract

In this paper we show predictions for the low-energy cross-sections and transport properties for the F − in Ar/BF3 mixtures which does not exist in the literature. These data are needed for modelling in numerous applications of technologically important Ar/BF3 discharges. Results for transport coefficients as a function of E/N (E is the electric field, N the gas density) were obtained by using the Monte Carlo technique. The Monte Carlo method is applied to obtain swarm parameters at the temperature T = 300 K.

Role of pressure in transport of F- ions in BF3 gas for technological applications

“…Elastic scattering in the low energy limit is controlled by polarization force and thus for the same target, the cross sections as a function of relative energy have almost identical shape. Nanbu's theory by assuming elastic collisions (EL), charge transfer collisions (CT) producing F2-+ BF2 [19] with threshold energy Et =5.6 eV, electron detachment (DET) with Et =3.4012 eV is applied [8] (See Fig. 1).…”

“…is included in the cross section set [8] and its cross section is shown in Figure 2. Competition between radiatively stabilized reaction (1) and elastic collisions is included in the cross section set.…”

“…Competition between radiatively stabilized reaction (1) and elastic collisions is included in the cross section set. Cross section representing three body association reactions at elevated pressure can be expressed with the same relation used for binary exothermic reaction [8]. Cross section and its pressure dependence comes from the rate coefficient for three body reaction that is reduced to two body rate coefficient [21] …”

“…[8]). Widest discrepancy with respect to E/N is related to lowest energies cut off of exothermic process (cut 0.1).…”

“…This reaction proceeds either with radiative or collisional stabilisation both with similar intensities at pressures of about 100 Pa and temperatures near room temperature [5]. Immediately follows that production of BF 4 -in three body association process needs to be included in all existing plasma models [6,7,8] for cases with similar pressures and temperatures.…”