80 research outputs found

    Thermal Metalorganic Chemical Vapor Deposition of Ti-Si-N Films for Diffusion Barrier Applications

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    Structurally disordered refractory ternary films such as titanium silicon nitride (Ti-Si-N) have potential as advanced diffusion barriers in future ULSI metallization schemes. Here the authors present results on purely thermal metalorganic chemical vapor deposition (CVD) of Ti-Si-N. At temperatures between 300 and 450 C, tetrakis(diethylamido)titanium (TDEAT), silane, and ammonia react to grow Ti-Si-N films with Si contents of 0--20 at.%. Typical impurity contents are 5--10 at.%H and 0.5 to 1.5 at.% C, with no O or other impurities detected in the bulk of the film. Although the film resistivity increases with increasing Si content, it remains below 1,000 {micro}{Omega}-cm for films with less than 5 at.% Si. These films are promising candidates for advanced diffusion barriers

    Structures of anhydrous and hydrated copper(II) hexafluoroacetylacetonate

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    Crystal structure analyses are reported for anhydrous copper(II) hexafluoroacetylacetonate (Cu(hfac)2) and for two of its hydrates. The anhydrous compound (Cu(hfac)2, 1: P1; at 100 K, a = 5.428(1), b = 5.849(1), c = 11.516(3) Å; α = 81.47(2), β = 74.57(2), γ = 86.96(2)°; Z = 1) contains centrosymmetric square-planar complexes with close intermolecular Cu···F contacts. The geometry of the complex is similar to that previously reported for Cu(hfac)2· toluene. The monoaquo compound (Cu(hfac)2(H2O), 2: P21/c; at 100 K, a = 10.8300(8), b = 6.5400(6), c = 21.551(3) Å; β = 90.282(8)°; Z = 4) consists of square-pyramidal molecules with apical H2O ligands, and close-lying F atoms in the sixth coordination sites. The major difference between this structure and the two other polymorphs previously reported is the nature and direction of hydrogen bonds. The yellow-green solid formed from Cu(hfac)2 with excess H2O is identified as the trihydrate. In crystalline form it is the previously unreported [trans-Cu(hfac)2-(H2O)2] ·H2O (3: P1; at 150 K, a = 8.3899(3), b = 9.6011(3), c = 11.4852(4) Å; α = 72.397(2), β = 79.161(2), γ = 87.843(2)°; Z = 2). There is no conclusive evidence in favor of any solid with the composition Cu(hfac)2· 2H2O

    Perception on the effects of an active lifestyle on mental health of Bachelor of Science in Nursing students at De La Salle Health Sciences Institute

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    A descriptive research using quantitative non-experimental research design was used in the research study. The target population was comprised of all male and female nursing students from level one to level four enrolled in academic year 2015-2016. Total population sampling was used as sampling method. An adapted-modified questionnaire was used as instrument and data was analysed using percentage, mean, standard deviation, t-test and f-test. The study concluded the following: (1) majority of the nursing students from De La Salle Health Sciences Institute were 18-20 years old, female, from first year level and having a monthly family income of Php 100,000-249,999; (2) the nursing students of De La Salle Health Sciences Institute had a very high perception on the effects of active lifestyle on mental health; (3) the perception on the effects of an active lifestyle on mental health of the respondents were the same regardless of their age, gender, year level, and monthly family income

    Rotational dynamics in a crystalline molecular gyroscope by variable-temperature C-13 NMR, H-2 NMR, X-ray diffraction, and force field calculations

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    A combination of solid-state C-13 CPMAS NMR, H-2 NMR, X-ray-determined anisotropic displacement parameters (ADPs), and molecular mechanics calculations were used to analyze the rotational dynamics of 1,4-bis[3,3,3-tris(m-methoxyphenyl)propynyl]benzene (3A), a structure that emulates a gyroscope with a p-phenylene group acting as a rotator and two m-methoxy-substituted trityl groups acting as a stator. The line shape analysis of VT C-13 CPMAS and broad-band H-2 NMR data were in remarkable agreement with each other, with rotational barriers of 11.3 and 11.5 kcal/mol, respectively. The barriers obtained by analysis of ADPs obtained by single-crystal X-ray diffraction at 100 and 200 K, assuming a sinusoidal potential, were 10.3 and 10.1 kcal, respectively. A similar analysis of an X-ray structure solved from data acquired at 300 K suggested a barrier of only 8.0 kcal/mol. Finally, a rotational potential calculated with a finite cluster model using molecular mechanics revealed a symmetric but nonsinusoidal potential that accounts relatively well for the X-ray-derived values and the NMR experimental results. It is speculated that the discrepancy between the barriers derived from low and high-temperature X-ray data may be due to an increase in anharmonicity, or to disorder, at the higher temperature values
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