This article is a review of the technology for the formation of three−dimensional structures in silicon carbide substrates. The technological solution of these problems ion−stimulation plasmochemistry etching in its various modifications, the most successful being by ICP sources (sources of inductively coupled plasma).

Silicon carbide consists of silicon and carbon which produce volatile fluorides in reaction with fluorine. Therefore for plasmochemistry etching of silicon carbide one uses fluorine−containing gases, most often sulfur hexafluoride (SF6), and sometimes with additions of oxygen and argon. During plasmochemistry etching of silicon carbide one  uses the  mask  the  material  of which does not interact with fluorine.  As a rule these are thin films of metals, e.g.  Cu, Al and Ni, and sometimes films of silicon oxides.

The most  important technological trend of this process is making through holes  by etching of SiC substrates with GaN epitaxial layers, and their subsequent metallization.

In this review we will present examples of ICP source applications for the formation of micro− and nano−sized three−dimensional structures in silicon carbide substrates, including  making  through holes  in SiC substrates with GaN epitaxial layers.

A historical  review of the  market of polysilicon  from the 1980th has been provided and a periodization of market development has been proposed. 2 development stages of solar power and world polysilicon production have been separated. A description of the historical dynamics of the polysilicon market, including technological estimates, possibilities of delivery, production expenses and application tendencies has been given. It is noted that a new oligopolistic structure of polysilicon market has appeared and new producers, especially in Asia, entered the limited scope of participants. This resulted in a greater than 10−fold increase in top−tier manufacturing capacity to an absoluteтamount of 320.000 MT/year in the period 2005—2015.

A prolonged and detrimental overcapacity−induced price reduction has followed with an average annual price decline of 30% over the past four years. The current average selling prices (ASP) of polysilicon are so low that do not promote the appearance of new participants of the market. However, in the absence of macroeconomic delay of economy, there is a high probability that an overproduction of poly−silicon will be balanced by a growth in its consumption in the next 3−4 years. Then today’s low polysilicon prices will not allow polysilicon industry to transfer into the category of investment attractive ones. Investment attractiveness in the market is a necessary condition of the transition to the following third development stage of the polysilicon market because the construction of modern polysilicon  production enterprises requires considerable expenses and  the  role of this factor  will ever  increase. Estimates of investment attractiveness of polysilicon price using the Internal Rate of Return  (IRR) have been offered. The area of the most  probable indicators (ASP, IRR, outputs, various unit invests  and cash−costs) has been outlined. These indicators have to be reached so that to achieve the 3rd stage of polysilicon market development.

Characteristics of crystal doping with electrically active impurities by the thermomigration method for two− and three−component liquid zones in comparison with diffusion alloying (for the example of silicon) have been analyzed.

We have  found  that  the  concentration range of doping for the  two− component migration zone is much narrower than the range of diffusion doping. Introduction of a third component into the liquid phase allows extending the range of doping thermomigration to values  exceeding the diffusion doping range for the same impurity. For silicon crystals this technological advantage of thermomigration is achieved with the use of three zones, GaxAl1−xSi and SnxAl1−xSi.

We show  that  the  speed of crystal  doping by the  thermomigration method in technologically relevant situations is by orders of magnitude higher  than that of diffusion alloying. Thermomigration doped layers with steadily moving liquid zones have higher structural perfection than diffusion doped layers.

We show that the thermomigration alloying method can be used in the technology of semiconductor device  structures, provided that  their planar dimensions and thickness are tens  micrometers or more. Quantitative results obtained for the example of liquid zone migration in silicon, but the features of thermomigration as a doping method are true for other  semiconductor materials.

Experimental results demonstrating the possibility of obtaining solar grade silicon by recrystallization of metallurgical silicon in fusible metals, e.g. tin, and pulling of single crystal silicon ingot obtained from silicon scales by the Czochralski method have been presented. Experiments for the purification of a fusible metal (tin) after the end of a cycle of silicon scales obtaining for the purpose of its reuse have been carried out. We purified tin by vacuum decontamination of tin melt, its filtration and finally zone recrystallization. Qualitative and quantitative analysis of the initial materials (silicon and tin) and their structure after sequential stages of the technological process has  been carried out by X−ray fluorescent analysis  on an Elvax light device. The structural features of the  silicon scales have  been examined using  scanning electron microscopy on a REMMA106I device. The conductivity  type and the electrical resistivity of the obtained single crystal silicon ingot have been measured using the four−probe method on a PIUS−1UM−K device. We show that the composition of the pulled single crystal ingot is not worse than 99.999 wt.% Si, it has the n type of conductivity  and its electrical resistivity is not less than 2.0 Оhm•сm. These parameters meet the requirements to solar grade silicon and confirm the possibility of its obtaining from metallurgical silicon by recrystallization in fusible metals, e.g.  tin.

This work presents a series of experimental studies aimed at validating  the  main theoretical aspects of ion−electron emission. Possibilities of practical implementation of the  method of operative control  of reactive ion−beam etching of different dielectric thin film materials for electronics have been found.

To obtain results on electron emission we have conducted a series of experiments with a specially  synthesized thin−film multilayer hetero- geneous compositions, i.e. Si₃N₄/Si, Ta₂O₅/Al/Si and Al/TiO₂/Si. Assessment of the effect of induced surface potential in the dielectric film on the integral signal of secondary electrons during reactive ion− beam etching allows one to confirm the dependence of the emission properties of thin dielectric films on the  electric field formed in the dielectric by the  surface potential induced by the  ion beam during reactive ion−beam etching.

We have noted that the secondary electron current emitted from the surface of dielectric films deposited on substrates of different materials differs in magnitude, i.e., it is determined by the emission properties of the substrate.

The electric field produced in the dielectric film by the induced potential creates preconditions for the  emergence of Malter emission deter- mined by the properties of the dielectric and the substrate.

Magnetoimpedance (MI) effect in amorphous ferromagnetic microwires represents is the ideal base for sensing technology and is currently used to develop high sensitive sensors of weak  magnetic fields with a resolution up to few micro−Oersteds. The effect  of heat treatment on off−diagonal MI in glass coated ferromagnetic amorphous microwires has been studied in order to improve MI sensitivity and temperature stability. We have shown the dependence of sensor signal on temperature. The wires had Co−based composition and internal stress induced helical or circumferential anisotropy. We have demonstrated that annealing of the entire sensing element including the electric contacts and the detection coil may improve the sensitivity of the output signal  to an external magnetic field by about 25% and  decrease its temperature sensitivity almost twofold in the −30…+80 °C range. These improvements require strict control  of the annealing parameters. The best results are obtained for annealing at 160 °C for 2−3 minutes. The experimentally observed changes  are  related with stress relaxation during  annealing; in particular; relaxation of the  stresses occurring during  solidification  due  to the  difference in the  thermal expansion coefficients of the metal core  and the glass sheet.

Methods and  results of studying diphenyl−2,2’,4,4’−tetraamine surface morphology and  structure obtained during  making the thin−film target of the Pyroelectric Thermal Image Transducer have been described. Quatum−chemical simulation  (HF/MP2,  cc−pVDZ base) of diphenyl−2,2’,4,4’−tetraamine (DPhTA) properties allows making conclusions on the nature of the pyroelectric properties of this polycrystalline material, since the hydrogen bonds between polycrystalline molecules are weaker than the intramolecular bonds.

The  research techniques were  X−ray  diffraction  analysis, optical  microscopy in polarized light, scanning electron microscopy, Fourier−transform IR spectroscopy, surface charge measurements of pyroelectric sample during  heating with the  use  of synchronous detection, testing of Pyroelectric Thermal  Image  Transducer targets on purpose−made high−vacuum technology equipment.

The methods of making  pyroelectric targets have  been described.

We have  manufactured the  Pyroelectric Thermal  Image  Transducer (λ =  8–14  microns, 18 mm diam.  target, 640х480 pixels) based on DPhTA in a metalloceramic case with a compact infrared imager having a resolution to 320х240 and a temperature sensitivity about 0.2 К in panning mode.

We have  studied the  phase and  impurity composition of Pd—Ba  and  Pt—Ba cathode alloys obtained on an A 535.02TO arc melting plant using a technology developed by AO Shokin NPP Istok. The study  showed that  the  concentration of detrimental impurities (C; Zn; Cu; Al) in the specimens is within the allowed range. Pd—Ba tapes are rich in Ba but this does not compromise their quality. We have confirmed the earlier found domination of two−phase composition in Pd—Ba and Pt—Ba alloys where  one of the phase is an intermetallic compound (Pd5Ba, Pt5Ba) and the other  is a noble metal(the matrix). The intermetallide is distributed in the  platinum  metal  matrix quite inhomogeneously, this tangibly impairing the operation parameters of cathodes produced from these alloys. For the first time we have shown the high efficiency  of transmission electron microscopy for studying Pd—Ba and  Pt—Ba cathode alloys. We have  for the first time found the Pd2О phase in Pd—Ba. It may significantly reduce the secondary electron emission coefficient and the quality of devices based on this alloy. We have determined the Pd and Pd5Ba grain size in the Pd—Ba alloys and the Pt and Pt5Ba grain size in the Pt—Ba alloys. All the Pd and Pt5Ba grains contain high densities of randomly arranged dislocations, and Pt5Ba grains  contain internal  stresses. Recommendations have been given concerning the improvement of the current Pd—Ba and Pt—Ba cathode alloy tape  technology.

We have analyzed the effect of volume and surface defects SiC substrates on structure and some electrophysical parameters of AlGaN/GaN epitaxial layer heterostructures grown on them. Regions with internal  stresses usually  induced by carbon rich disk−shaped inclusions were  detected in the  initial substrates. We show  experimentally that the presence of internal stresses in SiC could affect the microroughness of epitaxial  films in regions above stressed areas. Abrupt deterioration of electrophysical parameters was observed in regions of epitaxial films growing above areas with internal stresses in the substrate. AlGaN/GaN layers contain impurities  delivered to their bulk during epitaxy or preparatory operations.