Vol 46, No 2 (2017)

The process of the formation of carbon nanotube arrays on Ct–Me–N catalytic alloys of low nickel content (10–20 at %) by chemical vapor deposition, where Ct is a catalytic metal from the group of Ni, Co, Fe, and Pd, and Me is a transition metal of group IV–VII of the periodic table, was investigated. It is shown that CNT grow effectively when the alloy contains Ti, V, Cr, Zr, Hf, Nb, and Ta. The addition of nitrogen and oxygen to the alloy’s composition gives rise to a buildup of oxynitrides, expelling of the catalyst, and formation of its clusters on the surface. The replacement of metals in the alloy has an effect on the diameter of the CNT. Moreover, the alloy films 10–500 nm thick can be used for the CNT growth, which is responsible for high degree of homogeneity and the repeatability of the process. CNT growth was not observed when the alloy contained W and Re.

An approach to the formation of new composite material of the anode electrode for lithium-ion batteries composed of carbon nanotubes (CNTs) synthesized on a substrate coated with a silicon layer has been studied. The dependence of the cyclicity and specific capacity of such a material on the geometric parameters of a CNT array has been studied. Using a CNT/silicon composite, the battery prototypes have been assembled and their characteristics and behavior during prolonged storage have been studied.

This paper describes a technique for dry etching SiO₂ layers in MEMS technologies without the moving elements sticking. Etching the sacrificial SiO₂ in anhydrous HF (hydrofluoric acid in the gas phase) allows avoiding the subsequent complex operations of cleaning and drying, which are mandatory in the case of liquid etching. Using the HF/C₂H₅OH anhydrous mixture under low pressures makes it possible to prevent water condensation, which is due to etching in HF vapor, and allows one to employ gas-phase etching in surface MEMS technologies. The mechanisms and physicochemical processes taking place when etching thermal SiO₂ are discussed. The rate of etching thermal SiO₂ films is investigated at temperatures ranging from 30 to 50°С and under chamber pressures ranging from 10 to 20 kPa.

Quantum cryptography can provide almost complete security of the data transmitted in optical telecommunication systems by single photons based on the laws of quantum mechanics. The paper presents a brief overview of the element base and experimental investigations in the field of quantum cryptography and data transmission by single photons in atmospheric and optical fiber quantum communication lines. Two experimental setups for the single-photon quantum key distribution in the atmospheric and optical fiber quantum channels are described. The results of the quantum key distribution experiments performed on them are given.

One possible approach to the analytical solution of the 2D Poisson equation for potential in the workspace of a double-gate CMOS nanotransistor with a silicon-on-insulator structure with an inhomogeneously doped workspace as a Gaussian function is discussed. Based on the numerical solutions of the Poisson equation, the dependences of a number of major doping electrophysical characteristics, such as the potential distribution in the workspace, threshold voltage, and subthreshold current under different technological parameters on the dopant profile, are analyzed. For the selected topological standards, the optimization of the dopant profile parameters gives an additional opportunity to control the main characteristics, along with the thickness of the workspace and the thickness of the gated oxide of the front shutter, which is important in the analysis of the applicability of nanotransistor structures. The physical limitations to optimize the electrophysical characteristics, and in particular, the effective suppression of the short channel effects, are considered. The simulation results are in good accordance with the modeled data obtained using a commercially available for 2D simulation of the transistor structures ATLAS^TM software package.