Enhancement of Negative-Ion-Assisted Silicon Oxidation by Radio-Frequency Bias

Abstract

We derive an improved prescription for the merging of matrix elements with parton showers, extending the CKKW approach. A flavour-dependent phase space separation criterion is proposed. We show that this new method preserves the logarithmic accuracy of the shower, and that the original proposal can be derived from it. One of the main requirements for the method is a truncated shower algorithm. We outline the corresponding Monte Carlo procedures and apply the new prescription to QCD jet production in e + e − collisions and Drell-Yan lepton pair production. Explicit colour information from matrix elements obtained through colour sampling is incorporated in the merging and the influence of different prescriptions to assign colours in the large N C limit is studied. We assess the systematic uncertainties of the new method.

Probe diagnostics of electronegative plasmas with bi-Maxwellian electrons

“…12 To create a region with low T e ͑suitable to generate SF 6 Ϫ and SF 5 Ϫ ) a magnetic filter made of permanent magnets was used. The filter divided the plasma into the so-called source plasma ͑SPL͒ and target plasma ͑TPL͒.…”

“…The replacement of mobile electrons with heavy negative ions drastically changes the plasma behavior. Thus elaborate works concerning diagnostics techniques, [1][2][3][4] applications, 5,6 and theoretical investigations [7][8][9] have been published over the last years. Langmuir probes have often been used to diagnose the electronegative plasmas, due to their simplicity of construction.…”

“…25 V f decreased with about 1.5 V for 10 Ͻ␣*Ͻ100 compared with that for ␣*ϭ0, a result that was related to changes in the electron energy distribution function ͑EEDF͒ induced by the hot electrons. Hot electrons with T eh Ͼ1.5 eV cannot lead to SF 6 Ϫ and SF 5 Ϫ formation, because their related cross sections have an upper threshold energy about 1 eV. 26 They can produce only small amounts of F Ϫ and F 2 Ϫ since the electron attachment cross sections are at least two orders of magnitude lower than those for SF 6 Ϫ for T e Ͻ1 eV.…”

“…Hot electrons with T eh Ͼ1.5 eV cannot lead to SF 6 Ϫ and SF 5 Ϫ formation, because their related cross sections have an upper threshold energy about 1 eV. 26 They can produce only small amounts of F Ϫ and F 2 Ϫ since the electron attachment cross sections are at least two orders of magnitude lower than those for SF 6 Ϫ for T e Ͻ1 eV. Therefore hot energetic electrons can more easily form a distinct group than bulk electrons, of which contribution to plasma parameters cannot be neglected.…”

Effect of a Magnetic Filter Across the Exit Hole of a Flat Oxygen Plasma Source

“…By attaching one electron, oxygen can become a negative oxygen (O − ) ion, which is an anion radical. Several reports have indicated that O − ions cause strong oxidation in comparison with positive oxygen ions [3]. A recent study on plasma processing using an oxygen plasma suggested that the O − ions may play a key role in proceeding oxidation [4].…”