The processes of gettering of fast-diffusing metal impurities and structure defects in silicon, mainly used in the production of integrated circuits, power high-voltage devices, nuclear-doped silicon, are considered. The getters based on structural defects and gas-phase getters based on chlorine-containing compounds are analyzed. It is noted that for the formation of getters on the basis of structural defects, it is necessary to create internal sources for generation of dislocations and formation of precipitate — dislocation clusters. It is shown that dislocations are generated in the mouths of microfractures, which then form a sedentary dislocation grid on the non-working side of the plates. In the second case, defects are created in the area of the plate adjacent to the active layer of the electronic component. The process of creating an internal getter is based on the decomposition of a supersaturated solid oxygen solution in silicon, due to which a complex defect medium consisting of various precipitate-dislocation clusters is formed in the crystal. The packing defect as oxide precipitate with a cloud of Frank’s loops is formed. Two variants of creating an internal getter are considered — first is associated with the distillation of an oxygen impurity from the near-surface region of the plate, the second is associated with a fine adjustment of the distribution of vacancies along the plate thickness. The analysis of the influence of the getter as the defect structure reducing the magnitude of mechanical stress of the beginning of the generation of dislocations, which ultimately can determine the mechanical strength of the silicon wafer.

This paper also considers the mechanism of gas-phase medium impurities and defects gettering with the addition of chlorine-containing compounds. It is shown that at elevated temperatures, due to the interaction of silicon atoms with chlorine in the near-surface region of the plate, it is possible to create vacancies that penetrate the sample volume with some probability. As a result, the case DСv > 0, DCi £ 0 is realized, that leads to a change in the composition of microdefects and their density. The examples of practical application of heat treatment in chlorine-containing atmosphere silicon wafer during application of the oxide film, in the case of the target the need for dissolution of the microdefects and of the withdrawal of fast diffusing impurities from the crystal volume, and to prevent the formation of generation-recombination centers in the manufacturing process of devices and in a nuclear doping silicon.

Nowadays new high-energy emission detection technologies with use of materials doped with rare-earth activators appear. There is still a great need for the development of new inorganic scintillators for medical application in particular detection of X-rays and -grays. In this case, the scintillation materials must meet basic requirements: high optical quality, high light output, fast response time and et al. One of these materials is the scintillation crystal Gd₃Al₂Ga₃O₁₂ : Ce (GAGG : Ce) investigated in this work. Analysis of the literature data showed that the optical characteristics of Gd3Al2Ga3O12 : Ce have not been studied enough. Hence the GAGG : Ce optical parameters (spectral transmission and reflection) were measured by optical spectroscopy in the wavelength range 200—750 nm. We calculated values of the absorption and extinction coefficients, refractive indices and the optical band gap of the Gd₃Al₂Ga₃O₁₂ : Ce. We used two spectrophotometric methods to determine the values of the refractive index: Brewster angles (jB) and the reflection coefficients at a small incidence angle of light close to normal (R0). The obtained results were used to build dispersion dependences graphs of the refractive indices.

Finding the conditions of high-speed single crystal growth with an appropriate quality is a priority for the industrial production of crystalline materials. Crystals of potassium dihydrogen phosphate (KDP) are important optical materials, they are grown from an aqueous solution and an increase in the rate of growth and quality of a single crystal is of great practical importance.

In this paper, mathematical simulation of hydrodynamic and mass transfer processes in growing KDP crystals is performed. The flow and mass transfer are modeled within the framework of continuous medium, which is considered as an aqueous solution of a special salt — potassium dihydrogen phosphate. This salt dissolves in water to a saturation level at a high temperature. Then, such supersaturated solution is used to grow crystals at lower temperatures in non-flowing and flowing crystallizers. The mathematical model is considered in a conjugate formulation with allowance for mass transfer in the

«solution—crystal» system. Local features of hydrodynamics and mass transfer in a solution near the surface of a growing crystal are determined, which can affect on the local (for a particular place and direction) crystal growth rate and the formation of defects. The requirements to the crystallizers that provide the «necessary» hydrodynamics in the solution are discussed. Its validation is shown for the flow around a long horizontal plate simulating the growing facet of the crystal. The rate of precipitation of salt was evaluated by the proposed mathematical model, which matches the calculation of solution flow according to the Navier-Stokes equations for an incompressible fluid with a thermodynamic condition for the normal growth of a face under conditions of two-dimensional nucleation. The action of the flowing crystallizers was analyzed for various solution inflows (axial and ring) and its outflow through the axial bottom hole.

In the heat «cooling» investigated the temperature dependence of the specific heat capacity and thermodynamic functions doped strontium alloy AK1М2 in the range 298,15—900 K. Mathematical models are obtained that describe the change in these properties of alloys in the temperature range 298.15—900 K, as well as on the concentration of the doping component. It was found that with increasing temperature, specific heat capacity, enthalpy and entropy alloys increase, and the concentration up to 0.5 wt.% of the alloying element decreases. Gibbs energy values have an inverse relationship, i.e., temperature — decreases the content of alloying component — is up to 0.5 wt.% growing.

The etching of wafers of cadmium telluride in aqueous and nonaqueous solutions before the epitaxial process of building structures CdxHg1-xTe and its influence on the surface quality of epitaxial layers. As the etchants investigated 2—20 % solution of bromine in isobutyl alcohol, 5 % solution of bromine in methanol, dimethylsulfoxide, ethylene glycol, solutions of bromine in hydrobromic acid and mixed with glycerin, a saturated solution of potassium dichromate in sulfuric acid. The speed of etching was varied from 0.2 to 9 µm/min. Polishing Set nature of the etching substrate of cadmium telluride in 5 % solution of bromine in i-butanol, the dissolution process is diffusion in nature and is limited by the mass transfer of the reactants in the temperature range of 10—60 °C, depending on the concentration of bromine and the viscosity of the solution. Studied the morphology and surface finish of epitaxial layers of CdxHg1-xTe, depending on the method of etching the original substrate. Found the optimal compositions of etchants for precipitaciones processing of obtaining structures with a height of asperities of the surface at 0.1 atm.

Polycrystalline Sr₂FeMoO_6-δ specimens have been obtained by solid state synthesis from partially reduced SrFeO_2.52 and SrMoO₄ precursors. It has been shown that during oxygen desorption from the Sr₂FeMoO_6-δ compound in polythermal mode in a 5%H₂/Ar gas flow at different heating rates, the oxygen index 6–δ depends on the heating rate and does not achieve saturation at T = 1420 K. Oxygen diffusion activation energy calculation using the Merzhanov method has shown that at an early stage of oxygen desorption from the Sr₂FeMoO_6-δ compound the oxygen diffusion activation energy is the lowest Е_а = 76.7 kJ/mole at δ = 0.005. With an increase in the concentration of oxygen vacancies, the oxygen diffusion activation energy grows to Е_а = 156.3 kJ/mole at δ = 0.06. It has been found that the dδ/dt = f(Т) AND dδ/dt = f(δ) functions have a typical break which allows one to divide oxygen desorption in two process stages. It is hypothesized that an increase in the concentration of oxygen vacancies V ·· leads to their mutual interaction followed by ordering in the Fe/Mo–O1 crystallographic planes with the formation of various types of associations.

The non-local dispersion of longitudinal ultrasonic waves is shown to appear in the heterogeneous solids due to continuous spatial distributions of their density and/or elasticity (gradient solids). This dispersion gives rise to the diversity of ultrasonic transmittance spectra, including the broadband total reflectance plateau, total transmission and tunneling spectral ranges. The ultrasonic wave fields in gradient solids, formed by interference of forward and backward travelling waves as well as by evanescent and antievanescent modes are examined in the framework of exactly solvable models of media with continuously distributed density and elasticity. Examples of transmittance spectra for both metal and semiconductor gradient structures are presented, and the generality of concept of artificial non-local dispersion for gradient composite materials is considered. It should also be noted that the wave equation for acoustic waves in gradient media with a constant elasticity modulus and a certain predetermined density distribution reduces to an equation describing the electromagnetic wave propagation in transparent dielectric media. This formal similarity shows that the concept of nonlocal dispersion is common for both optical and acoustic phenomena, which opens the way to the direct use of physical concepts and exact mathematical solutions, developed for gradient optics, to solve the corresponding acoustic problems.