Surface nanostructures based on tantalum and aluminum oxides

Generalized results from investigations into the processes of formation of tantalum and aluminum oxide nanostructures and their multilayered systems produced by the method of molecular lamination on a (100) silicon surface and aluminum are reported. Conditions for the layer-by-layer growth of oxide structures and multilayered low-dimensional systems with alternating zones of the said oxides are determined. Dielectric characteristics of the synthesized nanostructures are evaluated.     

Electrophysical properties of doped epitaxial CdSe films

The electrophysical properties of epitaxial films of cadmium selenide doped with zinc or gallium are investigated. It is shown that in doped films intercrystalline barriers are absent, and the mechanism of electron scattering is close to the scattering mechanism in single crystals. It is suggested that the removal of the intercrystalline energy barrier is due to localization of part of the activator at intercrystallite boundaries and neutralization of acceptor states in neutral complexes. The difference between the doping effect of zinc and gallium is shown.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 52–56, March, 1977.     

Nanotechnology of low-dimensional oxide and nitride systems

The possibility of using correlation equations with inductive parametric constants for evaluating the reactivities of the functional groups on the surface and predicting the conditions of surface reactions employed in chemical nanotechnological processes in silicon oxide and nitride nanostructures was demonstrated.     

Molecular Layer Deposition of Silicon Nitride with Glow Discharge Activation

Russian Journal of Physical Chemistry A - The formation of silicon-nitrogen nanolayers obtained by molecular layer deposition on the GaAs surface with (100) and (110) orientations in the...     

Features of current carrier scattering in epitaxial films

The properties of epitaxial cadmium selenide films obtained by condensation in a vacuum on mica substrates under almost equilibrium conditions are investigated. The temperature dependences of the conductivity and current carrier mobility and concentration are studied. The electron concentration in the films depended on the gas phase composition (coevaporation of CdSe + Se or CdSe + In) and varied between 5·10¹⁰cm^–3 and 3.5·10¹⁸. It is shown that the current carrier scattering mechanism depends on their concentration and production conditions. For n₁ 10¹⁶ cm^–2 (T_S520C),n₂ < 10¹⁵ (T_S=630C), scattering on intercrystallite barriers predominated. For n₁ and n₂ greater than the quantities mentioned, scattering by ionized defects becomes dominant. It is established that the magnitude of the intercrystallite barrier in films with 10¹⁵ < n < 10¹⁶ cm^–3 is comparatively small and does not exceed 4·10^–3 eV, whereupon scattering at the barriers is not explicitly manifest. Concentrations of the ionized centers, magnitudes of the intercrystallite barriers, and ionization energies of the donor levels are determined for films obtained under different conditions.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 98–103, September, 1977.     

Dielectric multilayer nanostructures of tantalum and aluminum oxides

This paper reports on the experimental results of investigations into the mechanism of formation and dielectric characteristics of multilayer nanostructures prepared through the molecular layer-by-layer growth of tantalum and aluminum oxides. It is demonstrated that the permittivity of the multilayer nanostructures varies almost linearly with a change in the content of the components. The electrical conductivity depends on the ratio between the Al₂O₃ layer thickness d_i and the Ta₂O₅ layer thickness d_j. For a layer thickness d_i (d_j)<5 nm, the tunneling phenomena contribute significantly to the permittivity and conductivity of these nanostructures.     

Atomic-layer deposition of cadmium chalcogenides on silicon

The results of studies of the synthesis of ultrafine layers of cadmium selenide and telluride by atomic-layer deposition on the silicon surface of different orientations were summarized. The main tendencies of the chemisorption of the components and conditions of layer growth during the formation of nanostructures of these compounds were determined.     

Conductivity peculiarities in epitaxial layers of cadmium selenide

Electrophysical properties are studied in epitaxial cadmium selenide films produced by condensation on common mica and fluorophlogopite substrates over a wide range of substrate temperatures (T_s). It is shown that under conditions close to equilibrium highly perfect layers are produced with charge carrier mobility up to 300 cm²/V · sec and concentration ～ 10¹⁶ cm^?3. The temperature dependence of carrier concentration and mobility are studied in undoped and doped CdSe films. The values of the intercrystallite energy barriers are determined in layers condensed at differing T_s. It is shown that at T_s>630?C the charge carrier diffusion mechanism is close to that of a monocrystal, while for a barrier diffusion mechansim (T_s<630?C) the character of the energy barriers for the cubic and hexagonal phases in CdSe is somewhat different. Donor-level ionization energy and ionized center concentration are determined.