Investigation on multilayered chemical vapor deposited Ti/TiN films as the diffusion barriers in Cu and Al metallization J.Hardness enhancement by compositionally modulated structure of Ti/TiN multilayer films

No abstract

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The alignment of a nematic liquid crystal, 4'-n-pentyl-4-cyanobiphenyl (5CB), on several smooth metal (Cr, Cu, Ag, and Au) surfaces was observed experimentally. Perpendicular (homeotropic) induced alignment was observed for Cu and Ag boundary layers, whereas parallel alignment was observed for Cr and Au. These differences are discussed in relation to the differences in chemical bonding interactions at the surfaces as described by theoretical calculations performed for the cases of Cu, Cr, and Au. Several differences in orbital interactions, as well as a sensitivity to bonding configurations, are illustrated with the aid of extended Huckel calculations on hypothetical organometallic complexes and extended-Huckeltight-binding calculations of the interface for parallel versus perpendicular adsorbate orientations.

Optical techniques have been used to study the extended persistence of luminescence in willemite phosphors coactivated with Mn and As. Absorption and photoluminescence excitation spectroscopy establish that the MnnormalZn2+ impurity ground state lies 3.9±0.1 normaleV below the conduction bandedge in willemite. Laser pulse excitation at energies > 3.9 eV has been used to generate MnnormalZn2+ luminescence decay curves. At short times false(t<100 normalmsfalse) , the shape of these decay curves depends strongly on both temperature and As concentration in the samples false(NnormalAsfalse) . These pulse response curves have been analyzed using a bimolecular kinetic model. The behavior of the model parameters as a function of NnormalAs is interpreted in terms of a diffusion‐controlled recombination between trapped electrons and ionized Mn centers. When NnormalAs <1×1019 cm−3 , the recombination is dominated by thermal emission of electrons to the conduction band. When NnormalAs>2 ×1019 cm−3 , diffusion by intertrap tunneling is dominant.