Abstract: The equilibrium bond length, harmonic frequency, first and second order anharmonicity constants, rotational and centrifugal distortion constants, as well as the rotation-vibrational and centrifugal coupling constants for the ground X(2) Sigma(+) and first excited A(2) Pi states of the SiN radical have been calculated at the complete active space SCF (CASSCF), multireference CI (MRCI) and coupled cluster (CCSD(T)) levels using Dunning's correlation-consistent basis sets. The excitation energy of the A(2) Pi State has also been computed at these theoretical levels. Dipole moments of SiN in the X(2) Sigma(+) and A(2) Pi states are given. Our study shows that core correlation must be considered in order to obtain satisfactory accuracy for the spectroscopic constants.

Abstract: Magnetic Pole Enhanced-Inductively Coupled Plasmas (MaPE-ICPs) in analogy to the conventional ICPs exhibit two modes of operation, depending on the power coupling mechanism, i.e., a low power mode with dominant capacitive coupling (E-mode) and a high power mode with dominant inductive coupling (H-mode). A comparative study of the electron temperature measured by a Langmuir probe (T-e(LP)) and the electron excitation temperature (T-exc(OES)) determined by Optical Emission Spectroscopy (OES) is reported in the two distinct modes of a MaPE-ICP operated in argon. The dependence of T-e(LP), T-exc(OES) and their ratio (T-e(LP)/T-exc(OES)) on applied power (5-50 W) and gas pressure (15-60 mTorr) is explored, and the validity of T-exc(OES) as an alternative diagnostic to T-e(LP) is tested in the two modes of MaPE-ICP. The OES based non-invasive measurement of the plasma parameters such as electron temperature is very useful for plasma processing applications in which probe measurements are limited. (C) 2013 Elsevier B. V. All rights reserved.

Abstract: This study is dedicated to a better understanding of the processes occurring under ion bombardment of ultra-thin ZrO2/SiO2/Si gate dielectric stacks. Complex-shaped depth profiles were obtained by using TOF-SIMS with dual beam (500 eV for sputtering and 10 keV for analysis) Ar+ ions. The SIMS intensities of all the elements depend critically on the amount of oxygen at any moment of the sputtering process. Increased intensity is observed at the surface and at the ZrO2/SiO2 interface. A long tail of the Zr signal is present in the Si substrate, even after the second (SiO2/Si) interface, and a double bump structure in the Zr-90 and ZrO dimer is observed, which is more pronounced with increasing thickness of the interfacial SiO2 layer. Computer simulations using the dynamic Monte Carlo code (TRIDYN) are performed in order to distinguish the ion bombardment-induced effects from changes in the ionization degree. The original code is extended with simple models for the ionization mechanism and for the molecular yield during sputtering. Oxygen preferential sputtering at the surface and ballistic transport of Zr towards and through the interface are clearly demonstrated, but there is also evidence that due to recoil implantation oxygen gets piled-up near the ZrO2/SiO2 interface. (C) 2004 Elsevier B.V. All rights reserved.

Abstract: The six platinum group elements (Ru, Rh, Pd, Os, Ir and Pt) can be determined in geological samples down to the μg kg−1 level, by using nickel sulphide fire assay and neutron activation of the residue ramaining after dissolution of the nickel sulphide button in concentrated hydrochloric acid. Losses for the platinum group elements during this dissolution step are usually insignificant, except when the elements are present at ultra-trace levels. The can be recovered from the filtrate by coprecipitation with tellerium. The latter approach also permits determination of silver, which is significantly lost in the hydrochloric acid treatment (recovery <98% instead of typically ≈ 10%). The coprecipitation with tellurium considerably improves the results for gold (recovery ≈ 95% instead of typically 75%).