Dmitri Kulikov | Saint Petersburg Academic University (original) (raw)

Papers by Dmitri Kulikov

physica status solidi (a)

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms

ABSTRACT The influence of the implantation sequence on the defect and implant distribution during... more ABSTRACT The influence of the implantation sequence on the defect and implant distribution during (SiC)1−x(AlN)x formation was studied by Rutherford backscattering spectrometry/ion channelling (RBS/C) and elastic recoil detection. It is shown that the implantation sequence aluminum followed by nitrogen lead to an improved crystallinity compared to the reverse implantation sequence for implantation temperatures above 400°C. The results obtained are discussed in relation to the defects distributions calculated by using a developed model which includes the effect of stress self-consistently.

Technical Physics Letters

ABSTRACT A physical model is proposed for the growth of GaAs nanowhiskers (NWs) with inhomogeneou... more ABSTRACT A physical model is proposed for the growth of GaAs nanowhiskers (NWs) with inhomogeneous crystal structures during the molecular beam epitaxy. Numerical calculations performed using this model give the temporal variation of the growth rate and the height of NWs and indicate the moments of switching from one crystal phase to another. The results of calculations coincide with the available experimental data.

Vacuum

A model is proposed of c-BN growth during the ion Beam assisted deposition procces. This phase ap... more A model is proposed of c-BN growth during the ion Beam assisted deposition procces. This phase appears when N and B atoms in h-BN create inserted ab-planes that increase the density of the material, resulting in transition from h-BN to c-BN. The aim is to simulate the processes that occur in growing BN films that lead to the phase transition.

Bulletin of the Russian Academy of Sciences: Physics

ABSTRACT The processes of nucleation and growth of GaN, Ge, and InAs nanoclusters in molecular be... more ABSTRACT The processes of nucleation and growth of GaN, Ge, and InAs nanoclusters in molecular beam epitaxy (conventional and nitrogen-ion-assisted) have been investigated by computer simulation methods. Physical models are proposed to explain the regularities of nanostructure evolution, depending on the epitaxy conditions. The role of nitrogen-ion irradiation, leading to radical changes in the epitaxial growth regime, is revealed.

physica status solidi (b)

Materials Science Forum, 2016

Computer simulation of the concentration profiles evolution in SiC/Si heterostructures during gro... more Computer simulation of the concentration profiles evolution in SiC/Si heterostructures during growth and subsequent ion sputtering is presented. Simulation is based on a complex self-consistent approach combining kinetic and ballistic methods. Within the framework of the proposed method concentration depth profiles in SiC/Si heterostructure with pre-deposited Ge impurity are calculated and compared with experimental sputtering profiles obtained by secondary ion mass spectrometry.

Proceedings of SPIE - The International Society for Optical Engineering

The diffusion processes in silicon carbide under Al+ and N+ ion implantation and subsequent annea... more The diffusion processes in silicon carbide under Al+ and N+ ion implantation and subsequent annealing have been investigated. The influence of an internal stress field due to point defect clusters has been taken into account. The clusters of interstitials, ions, and impurities have been created during irradiation. The compression stress field due to these complexes has decreased the diffusion of interstitials. The defect profiles have been calculated which have been in good agreement with experimental RBS/C results.

International Workshop on New Approaches to High-Tech Materials: Nondestructive Testing and Computer Simulations in Materials Science and Engineering, 1998

ABSTRACT Neutron irradiation of HTSCs creates a wide spectrum of defect sizes. In this work, the ... more ABSTRACT Neutron irradiation of HTSCs creates a wide spectrum of defect sizes. In this work, the influence of small defects on the critical temperature and critical current density Jc is investigated. The characteristic behavior of Tc and Jc under this treatment is satisfactorily explained by a theoretical model considering the creation, migration and annihilation of small defects in the oxygen sublattice.

SPIE Proceedings, 1999

ABSTRACT Interest of conductive cluster physics is stimulated by its possible applications to nan... more ABSTRACT Interest of conductive cluster physics is stimulated by its possible applications to nano- and micro-electronics. Modification of Diamond Like Carbon (DLC) properties by introduction of metallic nanoclusters (e.g. copper) is of great interest because of the possibility to vary useful properties of the material and to give deeper insight into its structure. One of the way to make DLC film is to grown it by ion co-sputtering of graphite and copper. The grown films have been investigated by electron microscopy (TEM), Selected Area Electron Diffraction (SAED) and optical absorption. In present work the model is proposed of evolution of copper nanoclusters during DLC film growth. The size distribution function of these clusters have been obtained with satisfactory agreement with experimental results. The value of surface activation migration energy of copper has been estimated. The main assumptions of the model are the following: (1) Numerical estimations show that during film growth copper and carbon atoms fall on film surface with low energy insufficient to deep penetrate into the sample. Therefore only surface processes are taken into account. (2) Copper atoms may diffuse only on film surface, because copper diffusion in bulk DLC is negligible. So all diffusion processes occur during growth of one or two monolayers of the film. (3) Diffusing copper atoms may create bi-clusters and join to already existing clusters to form clusters with bigger sizes. So copper clusters with different sizes exist in the film.

Fourth International Workshop on Nondestructive Testing and Computer Simulations in Science and Engineering, 2001

The response of ferroelectric materials to high energy irradiation is of great interest because o... more The response of ferroelectric materials to high energy irradiation is of great interest because of their possible application in radiation environments such as thermonuclear reactors. In the present work a physical model for the defect evolution in PLZT ceramics under neutron ...

ABSTRACT A model describing the changes of the Curie-Weiss temperature in lead-zirconate thin fil... more ABSTRACT A model describing the changes of the Curie-Weiss temperature in lead-zirconate thin films under neutron irradiation is proposed. The Curie-Weiss temperature in the irradiated material decreases which is connected to charges caused by neutron irradiation. The charges located near the surfaces due to Schottky effect and in the bulk of the film results in different rates of the Curie-Weiss temperature decreases with neutron fluence. However the influence of the Schottky layers seems to be more pronounced. Satisfactory agreement between the theoretical results and the experimental data is obtained for different neutron fluences.

International Workshop on Nondestructive Testing and Computer Simulations in Science and Engineering, 1999

The (SiC)1(AlN) system is being extensively investigated due to the full miscibility of the two c... more The (SiC)1(AlN) system is being extensively investigated due to the full miscibility of the two constituents, SiC and A1N, their good thermal and lattice matches, and the the possibility of modifying the band gap of the resulting structure over a wide range of 2.9 eV (6H-SiC) to 6.2 eV (2H-AIN) [1]. From a practical viewpoint, the solid solutions of SiC and A1N are promising materials for advanced high-temperature electronic and optoelectronic devices. One novel method of producing thin layers of(SiC)1(AlN) potentially suitable for microelectronic applications is the use of N and Al co-implantation into 6H-SiC at elevated temperatures followed by annealing, i.e. ion-beam synthesis. Hitherto, to the best of our knowledge, there has been only one report on the formation ofburied (SiC)1(AlN) layers in 6H-SiC by ion-beam synthesis [2]. This work is an attempt to model the fundamental processes that occur when 6H-SiC is implanted at elevated substrate temperatures with high doses of N and J ions to form thin buried layers of (SiC)1(AlN) having predetermined composition and dimensions. Results from the calculations have been correlated with those obtained by Rutherford backscattering/ channelling spectrometry (RBS/C).

ABSTRACT The (SiC)1-x(AlN)x binary system is widely investigated now. In reference 1 the possibil... more ABSTRACT The (SiC)1-x(AlN)x binary system is widely investigated now. In reference 1 the possibility of using of ion implantation (Al+ and N+) in 6H-SiC under high temperatures to create (SiC)1-x(AlN)x is first reported. The samples having been heated to 200 degrees Celsius, 400 degrees Celsius, 600 degrees Celsius and 800 degrees Celsius have been irradiated by ions, and after it the RBS-profiles of generated defects have been obtained. Then the samples have been annealed at 1200 degrees Celsius and RBS- spectra have been obtained again. The main results obtained in reference 1 and 2 are presented. In reference 2 - 4 we suggested the model of defect structure evolution in silicon carbide under ion irradiation. The aim of this work is to develop this model taking into account internal stress field.

Bulletin of the Russian Academy of Sciences: Physics, 2010

ABSTRACT Structures grown using the technique of molecular-beam epitaxy during deposition of carb... more ABSTRACT Structures grown using the technique of molecular-beam epitaxy during deposition of carbon and/or germanium atoms on an Si(111) surface were investigated experimentally and theoretically. Experimental profiles of in-depth component distribution were obtained using SIMS-profiling, whereas a complex technique of computer simulation taking into account diffusion and ballistic processes was applied for the calculated profiles.