Thermally Induced Viscous Flow of Borophosphosilicate-Glass Thin Films on Stepped Surfaces,Part 2: Generalized Parameters for ULSI Glass Flow Characterization

New flow parameters termed flow effectiveness andthermal budgetare used for the characterization of the thermal flow of borophosphosilicate glass serving as a premetal dielectric in ULSI circuits. Their practical value is discussed. It is concluded that the approach proposed reduces the cost of measurement, facilitates the interpretation of measured data, works for both furnace and rapid thermal annealing, is applicable to ULSI gap filling as well as glass planarization, and enables one to optimize the annealing temperature for thin films of low-fusible multicomponent glasses.     

Correlations in the director-orientation fluctuations in the presence of microscopic impurities in a nematic liquid crystal

The model of a spatially restricted liquid-crystal system with microscopic impurities homogeneously distributed in the system is considered. The thermodynamic correlations of the director-orientation fluctuations and the correlations of the scalar order parameter characterizing impurities in the system are investigated for this system. It is shown that the impurity correlations are weaker than in a pure isotropic liquid. The correlations in the director deviations depend essentially on the wavevector and can be substantially weakened in the presence of impurities.     

Einige Gesetzmäßigkeiten der spontanen Umwandlung der Wasserstofform des Montmorillonits in die Aluminium-form

Ohne Zusammenfassung     

Interaction and adhesion properties of polyelectrolyte multilayers

The growth, morphology, and interaction/adhesion properties of supported poly(sodium 4-styrenesulfonate)/poly(allylamine hydrochloride) (PSS/PAH) and DNA/PAH multilayers were investigated by means of surface plasmon resonance spectroscopy, atomic force microscope (AFM) imaging, and AFM-related force measurements. Multilayers were assembled on a prelayer of poly(ethylenimine) (PEI) both with and without drying. SPR results showed a linear growth of the assembly in the case of PSS/PAH multilayers and nonlinear growth for DNA/PAH multilayers. Measurements of forces acting between a bare glass sphere and a multilayer-coated surface indicated repulsive or attractive forces, depending on surface charge, which suggests that, on approach, electrostatic forces dominate. On separation, we observed large pull-off forces in the case of positively charged multilayers and weak pull-off forces in the case negatively charged multilayers. Multiple adhesions and plateau regions observed on separation were interpreted in terms of a bridging of multiple polymer chains between the glass particle and the multilayer and a stretching of the polyelectrolyte loops. The dependence of the pull-off force on the number of deposited layers shows regular oscillations.     

Simulation of electron transport in GaAs/AlAs superlattices with a small number of periods for the THz frequency range

The electron transport in superlattices based on GaAs/AlAs heterostructures with a small number of periods (6 periods) is calculated by the Monte Carlo method. These superlattices are used in terahertz diodes for the frequency stabilization of quantum cascade lasers in the range up to 4.7 THz. The band structure of superlattices with different numbers of AlAs monolayers is considered and their current–voltage characteristics are calculated. The calculated current–voltage characteristics are compared with the experimental data. The possibility of the efficient application of these superlattices in the THz frequency range is established both theoretically and experimentally.     

The Influence of Film Thickness on Annealing-Induced Grain Growth in Pt Films

Technical Physics - Pt films with thickness h = 20–100 nm deposited on oxidized с-Si(100) substrate have been subjected to vacuum annealing at 500°C for 1 h, which resulted in...     

RAFT synthesis of thioether-based,AB diblock copolymer nanocarriers for reactive oxygen species–triggered release

A well-defined AB diblock copolymer of 2-vinyl-4,4-dimethylazlactone (VDA) and N,N-dimethylacrylamide (DMA) was generated by reversible addition-fragmentation chain transfer (RAFT) radical polymerization. The VDA-DMA diblock copolymer was reacted with 2-(methylthio)ethylamine (MTEA) and 3-(methylthio)propylamine (MTPA) to yield two novel thioether functional diblock copolymers whose structure was confirmed using ¹H NMR and FTIR spectroscopy. Both diblock copolymers formed micelles (20–30 nm) in aqueous media as confirmed by dynamic light scattering (DLS) and transmission electron microscopy. The self-assembled micelles were loaded with Nile Red, a model hydrophobic drug to study their ROS-triggered release mechanism. On addition of hydrogen peroxide (H₂O₂), the most common ROS species, the hydrophobic thioether core of these micelles oxidized, and both diblock copolymers became more hydrophilic. This triggered their disassembly and subsequent cargo release as characterized by UV–visible spectroscopy. The Nile Red loaded micelles demonstrated similar in-vitro ROS-mediated release when exposed to endogenous oxidants in a model inflammation environment simulated by the presence of activated macrophages. The responsive nanomaterials developed in this article have promising potential as drug carriers in applications where ROS-triggered delivery of cargo is required such as in inflammatory conditions.     

Measurement of the relative probability of the decay φ → η′γ in the channel η′ → ηπ0π0, η → γγ

The process e ⁺ e ^? → η′γ, η′ → η π⁰π⁰, η → γγ is investigated by an SND detector in experiment on a VEPP-2M equipment with colliding electron-positron beams. The analysis of experimental data yields a value of B(? → η′γ)=(6.7 _?4.2 ^+5.0 ±1.5)×10^?5 for the decay probability. Taking into account a previous measurement of this quantity by an SND detector in the decay channel η′ → π⁺π^?η, one finally obtains B(?→η ′γ)=(6.7 _?2.4 ^+2.8 ±0.8)×10^?5.     

Borophosphosilicate glass films in silicon microelectronics,part 2: Structure and applications

The second part is presented of a review that summarizes the results of the 20-year research into CVD thin films of borophosphosilicate glass intended to serve as the premetal dielectric in multilevel metallization systems. The structure of the films and some aspects of their application are considered.Translated from Mikroelektronika, Vol. 34, No. 2, 2005, pp. 83–97.Original Russian Text Copyright © 2005 by Vasilev.Previously transliterated as Vassiliev and Vasilev.