Analysis of the N₂O dissociation in a RF discharge reactor

Abstract

In situ diagnostic measurements and reactor modelling are used to study the N2O dissociation by radio frequency (RF) discharges. Measurements are undertaken at 0.5 and 1 Torr gas pressure with a RF power density varying from 4.2 to 35.7 mW cm-2. The reactor modelling involves an electrical discharge model coupled to hydrodynamic and mass transfer models. Only an electrical discharge model accounting for the negative ion conversion from O- to NO- and the subsequent electron detachment allow a good coherence between the measured and predicted power densities. The electron-N2O dissociation cross sections are first fitted in the present work and then the corresponding dissociation rates, obtained from the electrical model, are used in the mass transfer model which includes eight species (N2O, N2, O2, NO, NO2, N, O(3P) and O(1D)). The corresponding results are in good agreement with the experimental ones related to the production of N2 and O2 and the consumption of N2O. Furthermore, the reactor model results show that N2 and O2 are the most abundant products (>1014 molecules/cm3) at 1 Torr.

Electron drift velocity in N2O in strong electric fields determined from rf breakdown curves

“…The calculated data for α/p coincide with previous measured [17] and calculated [18] data. The values of the attachment coefficient, η/p, we obtained are in satisfactory agreement with previous experimental [17] and calculated [18] data. Figure 7 shows the calculated dependence of the average electron energy, ε e on the reduced field, E/p, which is in satisfactory agreement with previous experimental [13] and calculated [20] values.…”

“…The solid curve presents the data calculated with the Bolsig code, solid circles are for our measured data (from the turning points), empty circles are for our measured data (from the minima), solid triangles are for the experimental data from [17], empty triangles are for the experimental data from [16], solid squares are for the experimental data from [15], empty squares are for the experimental data from [14] and solid diamonds are for the experimental data from [19]. The dashed curve presents the calculation data from [18].…”

“…However, while Teich [17] recorded the electron drift velocity up to E/p 174 V cm −1 Torr −1 , and Date et al [18] calculated it up to E/p = 322 V cm −1 Torr −1 , we determined the electron drift velocity over the range E/p = 87-840 V cm −1 Torr −1 . It is clear from figure 5 that our data are in good agreement with these two previous studies in the range E/p = 87-322 V cm −1 Torr −1 .…”

Optimization of PECVD process for ultra-thin tunnel SiO<inf>x</inf> film as passivation layer for silicon heterojunction solar cells

“…1 (a)). The dissociation analysis of the N 2 O molecules in a discharge plasma performed by Date et al [18] reveals that NO and N can be minor dissociated products besides the more abundant N 2 and O 2 . Also, Pai et al [19] have shown that N impurities and Si-H and N-H bonding groups that could be removed by adding He to the PECVD gas mixture.…”

Modes and the alpha-gamma transition in rf capacitive discharges in N2O at different rf frequencies

“…Consequently, it is of considerable interest to study the properties of rf capacitive discharges in pure N 2 O. However, published results are scarce, 13,14 and present only 3 V W characteristics together with discussions of the molecular dissociation. The process of N 2 O dissociation was also studied experimentally and theoretically.…”