The fluctuations in etch rates caused by changes in chamber conditions were studied. Excess deposition of C-F polymer on the chamber wall increased CF x density while H was consumed by the polymer and/or was deactivated on the conductive surface of Si electrodes. The change in radical densities had a clear relationship with the SiN etch rate. The etch rate was accurately predicted by statistical analysis using equipment engineering system (EES) data and optical emission spectroscopy (OES) signals which were extracted by considering both the physical model and the results of statistical analysis.

Articles you may be interested inEffects of plasma and vacuum-ultraviolet exposure on the mechanical properties of low-k porous organosilicate glass J. Appl. Phys. 116, 044103 (2014); 10.1063/1.4891501Plasma damage effects on low-k porous organosilicate glass Plasma-induced damage to porous SiOCH ͑p-SiOCH͒ films during organic resist film ashing using dual-frequency capacitively coupled O 2 plasmas was investigated using the pallet for plasma evaluation method developed by our group. The damage was characterized by ellipsometry and Fourier-transform infrared spectroscopy. Individual and synergetic damage associated with vacuum ultraviolet ͑VUV͒ and UV radiation, radicals, and ions in the O 2 plasma were clarified. It was found that the damage was caused not only by radicals but also by synergetic reactions of radicals with VUV and UV radiation emitted by the plasmas. It is noteworthy that the damage induced by plasma exposure without ion bombardment was larger than the damage with ion bombardment. These results differed from those obtained using an H 2 / N 2 plasma for resist ashing. Finally, the mechanism of damage to p-SiOCH caused by O 2 and H 2 / N 2 plasma ashing of organic resist films is discussed. These results are very important in understanding the mechanism of plasma-induced damage to p-SiOCH films.

We investigated the relationship between the hard mask faceting that occurs during organic low-k etching and the ion energy distribution function of a capacitively coupled plasma reactor. We minimized the hard mask faceting by precisely controlling the ion energy. This precise control was obtained by selecting the optimum bottom frequency and bias power. We measured the amount of damage done to a SiOCH film exposed to H2∕N2 plasma in order to find the H2∕N2 ratio at which the plasma caused the least damage. The amount of moisture uptake by the damaged SiOCH film is the dominant factor controlling the dielectric constant increase (Δk). To suppress Δk, the incident ion species and ion energies have to be precisely controlled. This reduces the number of adsorption sites in the bulk SiOCH and maintains the hydrophobic surface that suppresses water permeation during air exposure.

We perform an optimal-observable analysis of the final charged-lepton/b-quark momentum distributions in γγ → tt → X/bX for various beam polarizations in order to study possible anomalous ttγ, tbW and γγH couplings, which could be generated by SU(2) × U(1) gauge-invariant dimension-6 effective operators. We find optimal beam polarizations that will minimize the uncertainty in determination of those non-standard couplings. We also compare eē and γγ colliders from the viewpoint of the anomalous-topquark-coupling determination.

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