N.L. Dmitruk, T.A. Mikhailyk, V.R. Romaniuk
Morphology and Optical Properties of Island Metal FilmsThe local electrochemical deposition technology for preparing of island metal films on semiconductor surface have been elaborated. Morphology of coating in the range from isolated metal clusters to some fractal structures have been investigated by transmission electron microscopy and atomic force microscopy. Gold islands on the surface of GaAs have shape of truncated spheres with the height to diameter ratio of 1/3, approximately. As optical measurements we used the reflectance spectra of p-polarized visible light at several angles of incidence and monochromatic multi-angle-of-incidence ellipsometry. These data are interpreted by the modified Maxwell-Garnett theory taking into account the pair dipole interaction between nanoparticles (at low filling factor) or by the symmetrical Bruggeman approximation (at large gold covering). Using the obtained effective optical parameters we have calculated the dielectric function and the plasma frequency and the resistivity scattering frequency of gold in the cluster phase.
I
nvestigation of the Electrical and Optical Properties Zno:In Polycrystalline LayersNational University “Kharkov Polytechnic Institute”, Ukraine, 61002
Kharkov, Frunze Str, 21
boyko @ fmeg. kpi. kharkov. ua, root@fmeg.kpi.kharkov.ua
In activity the optical and electrical properties of ZnÎ:In layers of a substrate, obtained at temperatures, from 200
0Ñ up to 400 0Ñ were investigated by jet high-frequency magnetron sputtering of the metal Zn:In target with the contents 98 at of % Zn and 2 at of % In. Is established, that of a ZnO:In films the obtained at the temperature of substrates 400 0Ñ, have optimum electrical and optical parameters: the size of specific resistance, recordings by a thickness 1400 nm makes 18? 10-4 Îm? ñm at the transparency in a visible part of a spectrum 89 %.43009 Lutsk, Ukraine, E–mail: pikr@lab.univer.lutsk.ua
Investigation of: Eight polythermal sections of the quasiternary Cu2Se – ZnSe – Cu2SnSe3 system have been investigated using differential thermal, X-ray phase and microstructural analyses. The projection of the liquidus surface and the isothermal section at 670 K have been constructed. The quaternary compound Cu2ZnSnSe4, which melts inconngruently at 1061 K is formed in the system. It corresponds to the adamantine semiconductors and is an analogue of stannite. The compound crystallizes in the tetragonal stracture with the lattice parametres a=0,5855 (1) nm and c=1,1379 (3) nm. The character of mono- and nonvariant processes passing and their coordinates were determined.
The procedure and results of study of the spinel inversion degree and iron ion valent states in magnesium-zinc ferrites by X-ray structure analisys are presented. The changes in the valent states has been confirm by X-ray spectroscopy.
The influence of interdiffusion on optical properties of amorphous multilayer structure a-Se/As2S3 was investigated. Especially the changes of absorption coefficient a (hn ) and the index of refraction n were examined. One-oscillator model of Wemple and Di Dominico was for the calculations of the dispersion energy Ed, electron oscillator energy E0 for initial and phototreated samples. One-oscillator optical-refractometric equation was used determine the interconnetion between the index of refraction and bandgap width at interdiffusion processes in such multilayer.
By methods of an electronic Auger-spectroscopy, nuclear gamma - resonance, the radiographic analyses and metallography are explored oxidizings of epifilms of telluride of tin at izochrones and isothermal annealing in atmospheric oxygen.
Disperse of Increasing Films Chemical Compounds
*Donetsk National university, ** Donbass machine-building Academy,
*** Severodonetsk an institute of technology
83015, Donetsk, (062) 3384673, E-mail:volya@abc.donbass.com
On a base of the theory and analysis of experimental datas on 35 chemical compounds, increasing on crystalline substrates with the help of jet raising dust, the dependence of a disperse of their structure on a supersaturation of a mother phase by a diffusing componentr, temperature of increase , value of mismatch of conjugated crystal lattices, resilient constants of an increasing phase and specific free boundary energy is detected.
The common legitimacy is placed: with augmentation of an odds of products Rv T lnP
eff and 0,5 (D à/à)? E/n the dimensions of critical nuclei (especialy twodimensional) of increasing chemical compounds are reduced.The disperse of films estimated on a base of datas on the dimensions of critical nuclei of increasing phases. The dimensions of nuclei of compounds are in an interval 0,5 - 57 nm. The compounds with a low and high disperse are detected and the pathes of achievement of a required disperse increasing phases are defined
The offered model of quazychemistry reactions of natural nuclear defects formation in tin telluride crystals with simultaneous existence one and two-charging defects behind Schottky. On the basis of the analysis of a requirement of an electroneutrality the dependence of defects concentration both carriers of current from temperature and fractional pair pressure of a tellurium is found at embodying of two-temperature annealing.
By methods of two-crystals spectrometry and topography explore parameters of real structure (quantity of blocks of a mosaic, field of a coherent dispersion, nonuniform microstrain, mosaic structure, parameter of a lattice) epitaxial films of tin tellurium besieged by a method of a hot wall on fresh planes (111) monocrystals BaF2. The influence of technology factors of cultivation to these structural performances of a condensate sets.
The dependence of specific electrical conductivity (
s), efficient thermal electromotive forñe (a), and specific thermal capasity from composition of both solid solution PbTe-Gd2Te3 and PbTe-Tb2Te3 is investigated. The composition with optimal value of thermoelectric parameters is determined. The crystall-quasychemistry description of defect subsystem of the base matrix of solid solution is proposed.The possibility of essential modification of the near-surface layer of lead chalcogenides films placed under high temperature in vacuo is theoretically shown, when the stoichiometric composition and type of conductivity of a layer changes with the intense of evaporation of chalcogen. The spice-time distribution of chalcogenide’s and lead’s concentrations in the near-surface layer is investigated. The numerical calculations are fulfilled for a case of PbS films of p-type. The main results correspond to experimental data of a vacuum annealing of PbS films.
Interaction of AV2BVI3 Semiconductor
Compounds
with Metals
1
Institute for Semiconductor Physics NAS Ukraine, Prospect Nauki41, Kyiv, UkraineIt is shown that as well as in the cases of II – VI, III – VI, IV – VI and I – VI group semiconductors the comparison of experimental results about phase relations of AV2BVI3 semiconductor compounds with metals and given thermodynamic calculations testifies that the calculations of thermodynamic Gibbs potential changes in the systems AV2BVI3 – Me allow to determine the presence or absence of exchange interaction in each particular system with sufficient reliability. Such estimation becomes more reliable at the simultaneous examination of the phase diagrams of binary systems limiting each particular ternary system and taking into account the stability of all existing binary and ternary phases. The reasons of discrepancies between experimental data and thermodynamic calculations are discussed.
The discrete transpiration receives condensates of thin films from ZnSe to ZnSe+30% ml. Cu2Se. Are explored and are analysed electronoscopic photos and electronogrammes of condensates. Is shown, that of a film condence in cubic and hexagonal phase. Film was consist of separate grains, which sizes average 50-100 Å
. The adding in fusion mixture of copper selenide in amounts more than 20 % a ml sets, that Cu2Se gives in gradual increase of a germs coalescence role. Is detected, that in films ZnSe +30% ml. Cu2Se with orientation {111} vacancies complexes practically miss.In the article hypothesis of the colloid structure of a crystal glass materials is considered. The simplest model of the colloid structure of the hightemperature solution is presented. It is mentioned that micelle system rebuilding from complex to simple is arisen by solution temperature mires.
Processing of oxide systems in the magnetic field which are dispersed from the point of view of the colloid structure is proposed. It is pointed out that by power fields influence original changes in the structure of micelle. It should be stressed that changes in a structure define obtaining the glass with the best exploiter properties.
The process of homoepitaxy on screw dislocations including the role of kinetic processes on steps has been investigated. Analytical expressions have been obtained for dependence of spiral element velocity on radius of its effective curvature and for the radius of critical two-dimensional nucleus in the diffusion field of the first coil of the spiral under the condition that steps move in the diffusional-kinetic mode. On the basis of expressions obtained the numerical simulation of the process of polygonal spiral formation was made. It is shown that the dependence of distance between spiral coils on the radius of two-dimension critical nucleus has a non-linear character and is determined by not only thermodynamic factors (supersaturation, temperature, linear tension of steps), but depends on relation between velocities of diffusion supply of crystal growth units to steps and speed of their building in kinks on steps.
The analysis of the Ga2Se3 oxidation have been performed. It was established, that the processes of own oxide formation take place at the temperatures, higher than 600°
Ñ. The non - crystalline gallium oxide is formed as the product of the oxidation in the temperature range 600-850° Ñ. The crystallization of the gallium oxide with the formation of the crystalline b - modification takes place in the temperature range 800-850° Ñ. This process has been compared with crystallisation of Ga2Î3 during the oxidation of another’s gallium- containing semiconductors.The influence of different modes heat treatment on phase structure, structure and mechanical properties of a foundry alloy Al-5,5%Mg-2,5%Zn by the component of copper in an amount 0,35% is investigated. The positive influence of the copper and alloying composition AlC0,8Ti0,7 on a level of mechanical properties of a researched alloy is shown. For the given alloy the mode heat treatment is recommended which allows to raise a level of mechanical properties, in comparison with a used standard mode.
The Laws of a Dispersion and Transport Phenomena
in Electronic Crystals of the Lead Selenide Physics-Chemical Institute at the V.Stefanyk Precarpathian University
Shevchenko str., 57, Ivano-Frankivsk, 76000The main mechanisms of carrier scattering in the crystals of n-PbSe at the temperature range 4,2-300K in the concentration interval 1016-1020 cm-3 with usage of the quadratic and nonquadratic laws of the dispersion from variable effective mass are investigated. The best correspondence with experimental data of the quadratic law of a dispersion is received. The probable contribution of inelastic mechanisms in a scattering of charge carriers is analysed.
O.V. Bogatskiy Physics-Chemical Institute, Lyustdorfska Str., 86,
65080, Odessa,
Tel. 0482- 61- 82-
25, E-mail:
Data for short- wavelength (l 1) and long- wavelength (l 2) limits of the optical transparency intervals of some complex selenosulphides of spinel type MM'2S2Se2 ( M - Zn, Eu, M' - Ga, In) as well as Tl2Ge2(S,Se)5 have been given. Values of l 1 and l 2 were determined from the diffusion reflectance spectra and transparency spectra and they lie within limits 0,50? 0,60 m m and 20- 25 m m, respectively. Conclusion about the different type of chalcogen atoms co-ordination in the zinc and europium chalcospinels was made. Semiconductor character of conductivity of the some metal selenosulphides in the crystal and molten states was established. Due to the energetic parameters of conductivity ZnIn2S2Se2 was stated as the conductor with jumping mechanism, while at melting its substitution for quasizonic one is occurred. The composition Tl2Ge2(S,Se)5 in the molten state behaves itself as ionic- electronic conductor and does not appear as individual compound. The successful attempt to obtain thin- film coating by thermal vacuum evaporation of ZnIn2S2Se2 was realised and the value of l 1 of coating has been determined.
Investigation of Stability of Two Dimensional Crystal Lattice
Ivano-Frankivsk State University of the Oil and Gas, Karpatska Str., 15, 76000, Ukraine
In this paper, on the two-dimentional model it was shown that the crystal lattice can be unstable under influence of small shear deformation in specific conditions. It was found that the cause of this are, the first, potential geometry of the interatomic interaction and, the second, magnitude of thermal energy of atoms. In case of using the spherically symmetric potential for computer modeling crystall lattice the repulsive forces arise between the atoms and their nearest neighbours, which balanced by the attractive forces between atoms and their secondary neighbours. Such crystal lattice is unstable. Atomic planes slipes under small external forces. A group of atoms displace into position of lower potential energy.
Vasyl Stefanyk Precarpathian University, Shevchenko str., 57, Ivano-Frankivsk, 76000
The paper present features of design and process engineering in the forming memory schemes on the "Flash" and "Flotoõ" cells with use of system process engineering of microelectronics
.The problems of the modern technology dealing with the electronic-beam processing of the substrates from optical glass are discussed. To investigate the influence of the electronic-beam processing the ellipsometrical method in used.
The influence of the optical anisotropy of surface layers induced by mechanical pressure and microrelief of a surface substrates made from a glass
Ê-8 after electron beam processing on the ellipsometrical parameters is investigated. The developed technique allows to carry out precomputation of the micropressure influence in a surface layer. The undertaking of the computing experiment has shown that stress in the glass Ê-8 surface layers do not influence upon the results of the ellipsometrical measurements. The presence of a surface microrelief has a significant influence on the ellipsometrical parameters and it should be taken into account. Root-mean-square height of roughnesses complies with qualitative processing.Is explored features structure formation of titanium at its diffuse saturation by carbon in a mode thermocyclical processing (TCP) in an interval of temperatures 850-950 C envelops a point of polymorphic transformation of titanium (882 C). The physicochemical properties of titanium after the indicated chemical-heat treatment (CHT) – wear and high temperature oxidation are explored. By methods of a X-ray diffraction analysis set phase composition protective covers, generated at a temperature cycling and isothermal mode of cementation.
The thermoelectric properties of system Sn-Fe-Te in temperature range 300-900
Ê are explored. Set, that with growth of the content of a dope the thermoelectric properties of system are considerably improved. Is rotined, that in the field of 600 Ê are watched the best thermoelectric parameters for a composition x=0,05 at. % Fe2Te3.On the bases of three layers Petric model was made estimation of surface contribution on value carrier mobility for films p-PbTe, p-PbS.