Vol 48, No 6 (2019)

A historical overview of the development of domestic ion beam technology is presented. It is shown that the wide application of the ion beam technology is facilitated by (i) the creation of a method for compensating the positive space charge inside an ion-source accelerating gap by the negative space charge of electrons held in crossed electric and magnetic fields, which makes it possible to increase the density of the extracted ion current by orders of magnitude over the Child–Langmuir limitations; (ii) the development of the original cold cathode sources forming ion beams from almost any compounds; and (iii) the creation of the reactive ion beam etching technique characterized by precise etching with inert gas ion beams and the selectivity of liquid etching. Based on these advances, a series of ion source modifications and technological equipment are developed for use in the manufacture of micro- and nanoelectronic products, optics, piezoelectric quartz technology, medicine, and other fields. The ways of improving the ion beam technology by creating high-energy neutral particle sources and technologies based on their use are shown.

A model that allows calculating the effective charge of native and impurity ions during electromigration at the tilt grain boundary of metal is proposed for the first time. It is considered in the model that the main factor resulting in the difference in the values of the effective charge during electromigration at the boundary and in the volume of the monocrystal is the difference in their atomic densities. It has an effect on the electron wind force determining the value of the effective charge. In this work, the procedure of calculating the form-factors of ions is improved to carry out the specified calculations, and also the model approximations enabling us to relate the atomic density at the tilt grain boundary with the parameters of its structure are developed. The effective charges of aluminum and copper ions at the grain boundary of aluminum as a function of the grain boundary’s misorientation angle, texture of the grains forming the boundary, and temperature are calculated in the model.

The issues of modeling the basic electrophysical characteristics of fully depleted surrounding-gate CMOS nanotransistors with an unevenly doped working region are discussed. The case of a Gaussian impurity distribution in the radial direction with the maximum in the center of the working area is analyzed. A mathematical model of the potential distribution following from an analytical solution of the 2D Poisson equation is treated. The results of model calculations of the potential distribution of a sub-50 nm structures are in good agreement with the data obtained using the commercially available ATLAS^TM software package for the 2D modeling of transistor structures. Based on the obtained potential distributions, the characteristics of the current are calculated using the tested approach formulated in the charge separation concept. For the topological norms chosen, optimization of the steepness of the doping profile provides an additional opportunity to control the key characteristics, together with the radius of the working region and the thickness of the gate oxide. This is important when analyzing the applicability of the analyzed nanotransistor structures.

Experimental studies on the influence of the electric mode (active and passive) on dose of the radiation resistance of microcircuits of different structural and technological types and functional classes are carried out. The analysis of the results presented makes it possible to evaluate the effectiveness of a “cold” backup and the possibility of simulating the effects of low irradiation intensity in the passive mode.

It was established that the variable-range-hopping mechanism of dc-conductivity takes place in the GaS single crystal at low temperatures. The parameters of localized states in the forbidden gap of studieGaS samples have been evaluated. Dielectric properties (loss tangent, real (ε') and imaginary (ε'') parts of complex dielectric permittivity and ac-conductivity across the layers of the GaS layered single crystals have been studied in the frequency range f = 5 × 10⁴ to 3.5 × 10⁷ Hz. The results demonstrate that the dielectric dispersion in the GaS single crystal has a relaxation nature. Over the studied frequency range, the ac-conductivity of the GaS crystal varies as f^0.8, characteristic of hopping conduction through localized states near the Fermi level. The Fermi-level density of states, the spread of their energies, and the mean hop distance and time have been estimated.