Translation. Region: Russian Federal
Source: Peter the Great St Petersburg Polytechnic University – Peter the Great St Petersburg Polytechnic University –
Representatives of the Higher School of Engineering and Physics of SPbPU – professor, advisor to the rector’s office Alexey Filimonov and associate professor Vyacheslav Bondarenko – took part in the work of the XV International Scientific and Technical Conference “Micro- and Nanotechnologies in Electronics”, which was held in the Elbrus Educational and Scientific Complex of the Kabardino-Balkarian State University named after Kh. M. Berbekov.
At the conference, representatives of the scientific community from different regions of Russia, as well as Azerbaijan and Belarus, discussed current issues in research into the structure and properties of nanomaterials and nanosystems, and prospects for their application. 82 reports were presented on topics such as: physical and chemical properties of materials and structures of micro- and nanoelectronics; phase equilibria and transformations in materials of electronic equipment; technologies of nanomaterials and thin-film structures for micro- and nanoelectronics; devices and instruments; information and digital intelligent technologies and mathematical modeling in micro- and nanoelectronics.
Alexey Filimonov gave a plenary report on the topic “Nanoheterogeneous structures in solid solutions of antiferroelectrics and their dynamic nature”. Antiferroelectrics and their solid solutions have been known for almost 70 years. For a long time, the main attention was attracted by solid solutions of the PbZrxTi1-xO3 (PZT) type in the field of morphotropic compositions demonstrating ferroelectric properties and high values of piezoelectric coefficients. In the last two decades, compounds that are antiferroelectrics at room temperature have attracted great interest. The reason is the broad prospects for using such materials in fast capacitor-type electrical energy storage systems, as well as for creating electrocaloric devices or the basis for information storage systems on nanodomains and, first of all, on domain walls. The reason for using these materials is their high “compliance” with respect to external influences, due to the complex mesoscopic structure of the compounds.
Alexey Filimonov presented the results of a comprehensive study of incommensurate, modulated and nanodomain structures in PbZr1-xTixO3 crystals using synchrotron radiation scattering methods, which have been carried out for many years at the SPbPU Research and Educational Center for Physics of Nanocomposite Materials in Electronic Engineering together with colleagues from the Ioffe Institute of the Russian Academy of Sciences. The speaker presented the formation of antiphase domains of the antiferroelectric phase, antiphase domain boundaries and the effect of an electric field on them. In solid solutions of such compounds, polar antiphase domain boundaries with a width of about 4 nm are formed in the antiferroelectric phase, which can be oriented in a given direction upon cooling and application of an electric field. In solid solutions of antiferroelectrics of this group, a complex system of modulated and disproportionate structures arises, which are very labile with respect to external influences, which determines their high prospects for practical use.
Vyacheslav Bondarenko in the report “Natural size effect on the surface of alloyed III-nitrids in conditions of self-compensation” highlighted the problem of contact phenomena on the boundaries of semiconductor structures that is relevant for modern microelectronics. Nitriand technologies conquer the world. Already now, on the basis of the III-nitrides (Aln, Gan, Inn), devices of power microwave electronics and optoelectronic devices in the short-wave region of the spectrum are produced. Due to a number of electrophysical parameters of the indicated nitride materials, for example, the corresponding powerful field transistors with high -moving two -dimensional electronic gas can operate at frequencies of up to 100 GHz at temperatures up to 400 degrees. However, the widespread introduction of nitride materials is still prevented by the complexity of the technology for growing crystals of the III-nitrides due to the lack of suitable substrates. The presence of the difference in the parameters of the lattices means that synthesized crystals, as a rule, contain more than a billion linear defects (dislocations) of inconsistencies on a square centimeter of the surface. Dislocations in the III-nitrides-electrical defects-have a compensating effect and form random electric fields that modify the properties of the surface of the semiconductor data and contact structures, where the dimensional effects are significant. In the previously conducted studies, it was found that in the wide range of semiconductor systems on the surface and in contacts, there is a natural dimensional effect – the comparability of the lengths of screenings and the average distance between charged defects.
The report considered the natural size effect on the surface of alloyed III-nitrides using n-type gallium nitride as an example. It was shown that at high degrees of self-compensation, inhomogeneities of charged dislocation fields dominate on the surface. Thus, technologically permissible densities of misfit dislocations were established.
The conference participants went on an excursion to the Baksan Neutrino Observatory of the Institute for Nuclear Research of the Russian Academy of Sciences. This is the first (operating since 1973) and one of two large-scale underground laboratories operating in the world today, including a complex of unique installations that complement each other for interdisciplinary research at the intersection of fundamental physics, astrophysics and geophysics. Only in laboratories located deep underground can an extremely low level of background radiation be achieved, which is necessary for the majority of key studies in the field of neutrino physics and experiments aimed at searching for rare events in the physics of elementary particles. Only underground laboratories can provide conditions for the creation of ultra-low-background gamma spectrometers for determining trace amounts of radioactive impurities in materials used in low-background experiments.
In general, the works presented at the conference covered both the results of fundamental studies of the structure and properties of nanomaterials and nanosystems, and methods of their practical application. Based on the results of the conference, a collection of materials was published, posted on the Internet and indexed in the Russian Science Citation Index.
Photo: KVSU.ru
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