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It is advisable to control characteristics and rate of formation of nanoscale fi lms on InP by introducing chemostimulators, modifi ers, or both simultaneously during the thermal oxidation of semiconductors. The chemostimulating effect of the compounds is determined by their transit role as oxygen transmitters or their catalytic function. Modifi ers can affect the composition, surface morphology, structure, and properties of the fi lm without changing the fi lm growth rate. The effect of chemostimulators and modifi ers on a single process of fi lm synthesis with the desired properties was assumed to be productive. Purpose: Establishment of the effect of certain complex chemostimulators and modifi ers on the kinetics, growth mechanism, and properties of complex oxide fi lms on InP in the nanoscale thickness range. The object of the study was indium phosphide FIE-1A orientation (100). SnO2/InP and (40 % Co3O4+60 % MnO2)/InP heterostructures with a layer thickness of ~ 30 nm were formed by magnetron sputtering. Sulphate was deposited through the aerosol phase, followed by air drying and annealing at 200 °C for 30 min for the formation of the Bi2(SO4)3/InP heterostructures. SnO2/InP and InP samples were thermally oxidized under the infl uence of AlPO4 and Bi2(SO4)3, respectively, introduced into the gas phase in the temperature range 490-570 °C in an oxygen stream for 60 min. The thickness of the fi lms was controlled by laser and spectral ellipsometry and their phase and elemental composition were established by XRD and Auger electron spectroscopy, respectively. For the determination of the electrophysical properties of the films, the contacts were sprayed with aluminium and the resistivity was determined. The fundamental role of the physicochemical nature of the chemostimulator, its ability to transit interactions and the renewability of oxide forms in the process of InP thermal oxidation was established. The introduction of phosphate groups from AlPO4 into thermal oxide fi lms, with or without the deposition of SnO2 on the surface, led to the fi lm resistance similar to that for the oxidation of SnO2/InP heterostructures without the additional introduction of phosphates and was 8.5·107 Ohm·cm. Bi2(SO4)3, being a modifi er of the composition and properties of the fi lms, did not have a signifi cant chemostimulating effect. Films grown under its infl uence had a semiconductor characteristics (r ~ 106 Ohm·cm). The most effective was a 40 % Co3O4+ 60 % MnO2 complex chemostimulator, which determined the accelerated (up to 70 %) formation of fi lm by the catalytic-transit mechanism (up to 70 %), being a part of the synthesized fi lms and capable of purposefully modifying their properties by varying the content of components in it (XRD, SE).

The formation of oxide functional films on the surface of semiconductors is a serious technological challenge, which is even more complicated in the nanometre thickness range. It is necessary to form films with specified values of thickness, resistivity, and a certain surface morphology for practical applications. Such films are used in micro- and optoelectronics, environmental monitoring, and alternative energy devices. The goal of this work is to establish the features of the surface morphology of thin films formed as a result of the thermal oxidation of the MnO2/GaAs, V2O5/GaAs, V2O5/InP, MnO2/InP, TiO2/InP, and SnO2/InP heterostructures depending on the physicochemical nature of the components and the oxidation conditions. The synthesis of thin films on the InP and GaAs surfaces was carried out by thermal oxidation under the influence of magnetron-deposited layers of chemostimulator-modifiers. The thickness of the formed films and their composition were determined by laser ellipsometry, X-ray phase analysis, and infra-red spectroscopy. The scanning tunnel and atomic force microscopy were used to determine the morphological characteristics of the films and their dependence on the type of semiconductor substrate, the nature of the chemostimulator-modifier, and the conditions of the thermal oxidation. The application to the GaАs and InP surfaces of the most effective chemostimulator-modifiers (V2O5 and MnO2) of thermal oxidation and higher temperatures of the oxidation process contributed to the formation of smoother and nanostructured films.

Semiconductor devices of quantum electronics based on InP/GaInAsP heterostructures require the creation of non-defective chips for emitting devices and photodetectors. The production of such chips is impossible without a thorough technological study of the growth processes of epitaxial structures. One of the important problems in relation to the growth of such structures is the growth defects associated with the process of dissociation of indium phosphide on the surface during their growth. The aim of the work was the investigation of the process and mechanism of destruction (dissociation) of the surface of indium phosphide substrates in the range of growth temperatures of structures, as well as the study of methods and techniques that allow minimize the process of dissociation of surface of indium phosphide. The work provides studies of the growth processes of InP/GaInAsP heterostructures, from the liquid phase, taking into account the degradation processes of the growth surface and the mechanisms for the formation of dissociation defects. The schemes of the dissociation process of the InP on the surface of the substrate and the formation of the defective surface of the substrate were analysed. At the same time, technological methods allowing to minimize the dissociation of the surface compound during the process of liquid-phase epitaxy were shown. The original design of a graphite cassette allowing to minimize the dissociation of the indium phosphide substrate in the process of liquid-phase epitaxy was proposed

Thin-film objects with a reproducible temperature dependence of the resistance, thermally stable, and easy to obtain can be used as the sensitive elements in semiconductor gas sensors. The aim of this study was to create thin films on the InP surface under the influence of an oxide chemostimulator + inert component (PbO + Y2O3, respectively) compositions and to determine their gas-sensitive properties and their dependence on the formula of the composition. Thin films were synthesised on the InP surface by the method of chemically stimulated thermal oxidation under the influence of various PbO + Y2O3 compositions. The thickness of the formed films, their elemental and chemical composition were determined (by laser ellipsometry, X-ray phase analysis, and infra-red spectroscopy). A number of experiments were carried out to establish the gas-sensitive properties of the obtained films with respect to ammonia with concentrations of 120, 100, and 80 ppm. By chemically stimulated thermal oxidation, we obtained thin films with semiconductor properties on the InP surface. It was determined that the samples had n-type conductivity. A gas-sensitive response was detected in the presence of ammonia in the atmosphere. The ability to create thin films with a predetermined value of sensory response was demonstrated

Photon activation of various physicochemical processes by the radiation of powerful pulsed xenon lamps (radiation range of 0.2-1.2 µm) is one of the promising areas of material science. The aim of this study was to determine the effect of preoxidative pulsed photon treatment on the process of thermal oxidation of indium phosphide with a nanosized layer of V2O5 on the surface, as well as its effect on the composition and morphology of the formed films. We determined the optimal mode of pre-oxidative pulsed photon treatment of magnetron-formed V2O5/InP heterostructures with a radiation density of 15 J/cm2. By laser and spectral ellipsometry methods, photon activation of V2O5/InP before thermal oxidation was found to increase the thickness of the formed films practically twofold. X-ray diffraction analysis confirms the intensification of the phosphate formation process. The morphological characteristics of the films were determined by atomic force microscopy. Pre-oxidative pulsed photon treatment with an optimal radiation density of 15 J/cm2 activates the thermal oxidation of V2O5/InP heterostructures. It is associated with the formation of new active centres and accelerated rearrangement of chemical bonds in the intermediate complexes of the V2O5 catalyst with semiconductor components

Purpose. YFeO3 is distinguished by a variety of important practical properties (multiferroic, semiconductor, photocatalyst) in the visible region and others. The economic feasibility of the use of materials based on it is due to the highest prevalence of Yttrium among the entire range of rare-earth elements. New properties may appear in fi lms of the nanoscale thickness range; however, their synthesis by simple, economical, and technologically advanced methods is not an easy task. The purpose of this work was the synthesis of fi lms of nanoscale fi lms (Y2O3–Fe2O3) system on InP monocrystals, the determination of their composition and surface characteristics. Methods and methodology. Films of the nanoscale thickness range (laser, spectral ellipsometry) of the system (Y2O3-Fe2O3) on monocrystal InP were formed by centrifugation from a nitrate solution. For their primary treatment, thermal annealing (TA) or pulsed photon processing (PPP) methods were used; for the subsequent thermal oxidation of the formed heterostructures, samples without annealing were used. The phase composition was determined by X-ray diffraction analysis (XRD) and the surface characteristics were determined by atomic force (AFM) and scanning tunneling microscopy (STM). Results. The results of the study demonstrated, that fi lms that were grown without annealing are single-phase and consist of YFe2O4. The fi lms that were thermally annealed at 200 °С for 120 min were two-phase fi lms, and contained YFe2O4 and Fe2O3 with Fe3O4 (X-ray diffraction analysis). The most promising fi lms for further use were fi lms subjected to PPP in the regime of 50 J/cm2 for 0.4 s and thermal oxidation with the process parameters of 450 –550 °С for 10–60 min, in which YFe2O4 and YFeO3 were present. The results of AFM and STM indicated that annealing of samples with deposited layers of ferrite with subsequent thermal oxidation promoted the reduction of the grain size on the surface of the grown fi lm, but increases the average surface roughness compared to unannealed samples. Conclusions. Nanoscale fi lms of the (Y2O3–Fe2O3) system on monocrystal InP were synthesized by centrifugation, their compositions that correspond to various types of pretreatment and surface characteristics before and after thermal oxidation were established. We concluded that the most promising fi lms for further use were those that underwent IPP or thermal oxidation and contained YFe2O4 and YFeO3. Regulation of the ratio of these phases in the grown fi lms of the nanoscale thickness range on InP opens up the possibility of targeted control of their characteristics.

Purpose. The purpose of this work was to establish the infl uence of bismuth phosphate introduced through the gas phase on the InP thermal oxidation process and the determination of the composition of the formed fi lms. Methods and Methodology.Oxidation was performed on (100)-oriented polished single-crystal indium phosphide wafers (with a concentration of main charge carriers at 300 K of at least 5×1016 cm–3 and intrinsic n-type conductivity). The oxidation of InP was conducted at 475, 500, 530, and 550 °С in 30 L/h oxygen for 10–60 min using postoxidation. The thickness of the formed oxide fi lms was determined by laser ellipsometry (l = 632.8 nm) with an absolute error of ±1 nm. Results.The accelerating effect of bismuth phosphate on the process of fi lm formation was established. The magnitude of the acceleration is from 1.5 to 2 times and the maximum fi lm growth is achieved in the fi rst 10 min of oxidation. The transit mechanism of action of BiPO4 was established. The determining process is the formation of indium phosphate due to the secondary interaction of the oxide forms of the components of the substrate. The limiting stage is the diffusion of oxides in the solid phase, as evidenced by the values of n (0.22) and EEA (188 kJ/mol). The authors established a decrease in the EEA compared with the process of InP’s own thermal oxidation, which provides the accelerated formation of a fi lm on the surface of a semiconductor with chemostimulated thermal oxidation. IR spectroscopy, EPXMA, and X-ray phase analysis were used to study of fi lms on the surface of InP. The main components of the fi lms on the InP surface are indium oxide and indium phosphates of different composition. With an increase in temperature and oxidation time, the content of indium oxide in fi lms decreases, and the variety and amount of indium phosphates increases. Conclusions.This indicates the transformation of some phases to others during solid phase transformations and corresponds to the consumption of indium oxide during secondary processes in the fi lm without a signifi cant increase in its thickness. Bismuth phosphate plays the role of a chemostimulator of the thermal oxidation process of InP and may be a modifi er of the composition, and hence the properties of fi lms on its surface.

Purpose. At present, AIIIBV type compounds are considered to be the most promising semiconductors in modern electronics. They are widely used to create high-speed optoelectronic and microelectronic devices. One way to protect the surface of semiconductors is chalcogenide passivation, which to some extent prevents the negative effects of self-oxidation and reduces the density of surface states at the internal interface. The proposed method for modifying the InP surface is the simplest, since it does not require ultra-high vacuum conditions and allows controlling the process parameters. The purpose of this work is to establish the effect of the pre-treatment of the InP surface with sulphur vapours on the oxidation speed, the distribution of components in the fi lm, and the morphological characteristics and electrophysical properties. Methods and methodology. The modifi cation from the gas phase with sulphur vapour was carried out at the temperature of 170°C for 60 minutes, followed by thermal annealing of the samples for 10 minutes at the temperatures of 280 °C and 360 °C. Thermal oxidation of sulphurmodifi ed InP was carried out at a temperature of 530 °C for 60 minutes. Results. The modifi cation from the gas phase with sulphur vapour followed by thermal annealing of the samples for 10 minutes at the temperatures of 280 °C and 360 °C results in fi xing of the sulphur layer on the InP surface (the content is about 7 at. %). The study of the kinetic data of thermal oxidation of sulphur-modifi ed InP established the effect on the growth rate of the formed oxide fi lms. According to the AES data, the sulphur content in the synthesized fi lms was not detected, however, the difference in the distribution profi les of the substrate components and oxygen with the reference indicated the effect of preliminary surface treatment with sulphur on the process of thermal oxidation. The surface morphology of the fi lms formed by thermal oxidation of sulphur-modifi ed InP after annealing at 360 °C improves, which is manifested in an increase in grain order and decrease in fi lm roughness compared to both the controlled and modifi ed InP after annealing at 280 °C. Conclusions. The modifi cation by sulphur vapour of the InP surface positively affects the parameters of fi lm formation and improves their morphology. Films synthesized by thermal oxidation of surface-modifi ed InP possess semiconductor properties.

The effect of various planes was studied when growing epitaxial layers by liquid-phase epitaxy (LPE) on the profiled InP substrates. The studies allowed obtaining buried heterostructures in the InP/InGaAsP system and creating highly efficient laser diodes and image sensors. It was found that protruding mesa strips or in-depth mesa strips in the form of channels formed by the {111}А, {111}B, {110}, {112}A, or {221}A family of planes can be obtained with the corresponding selection of an etching agent, strip orientation, and a method of obtaining a masking coating. It was noted that in the case of the polarity of axes being in the direction of , the cut of mesa strips was conducted along the most densely packaged planes. This cut led to the difference in rates of both chemical etching and epitaxial burying of profiled surfaces. The cut was made along the planes at a low dissolution rate {111}A for a sphalerite lattice, to which the studied material, indium phosphide, belongs. Analysis of planes {110} and {Ī10} showed that the location of the most densely packaged planes {111}A and {111}B relative to them is different.

The thermal oxidation process of gallium arsenide and indium phosphide under the infl uence of binary oxides compositions has been studied (chemostimulator+chemostimulator and chemostimulator+inert component). Oxides-chemostimulators were oxides of p- and d-elements’ (Sb2O3, Bi2O3, PbO, CrO3, V2O5, MnO2, MnO), inerts components were – Ga2O3, Al2O3и Y2O3. The nonlinear effects of the oxide fi lm thickness on the GaAs and InP surfaces from the compositions oxides-chemostimulators have been studied and interpreted. Nonlinear effects are characterized by different signs of deviation from the additive straight – negative, positive and alternating. There is a clear correlation between the existence of acid-base and oxidation-reduction interactions in the compositions chemostimulators and nonlinear effect’s sign. If there is acid-base and oxidation-reduction interactions between the compositions of the oxides, then a positive nonlinear effect will be observed, increasing with growing time and temperature of oxidation. With the weakening of acid-base and oxidation-reduction interactions, a positive deviation from additive function is replaced by alternating signs. In case of the complete absence of interaction between the oxides in the composition, there is a negative deviation from additive function, increasing with growing time and temperature of oxidation. The possibility of obtaining the additive function for the entire range of compositions action of the oxide fi lm thickness on the GaAs surfaces from the compositions oxide-chemostimulator+inert component has been proven (inert component – Y2O3). The study of GaAs thermal oxidation under the infl uence of Sb2O3+ Ga2O3 compositions showed a signifi cant negative departure of the oxide fi lm thickness from the additive line for low Ga2O3 concentrations. When the Ga2O3 concentration in the compositions was higher than 40 mol %, the oxide fi lm thickness grown on GaAs was an additive function of the activator composition. The nonlinear effects observed were caused by the infl uence of small Ga2O3 additions on the vaporization dynamics of antimony oxide through the enhancement of Sb2O3 sintering during the experiment. The spation localization of binding interactions between oxideschemostimulators was revealed, which leads to the nonlinear effects. The solid-phase interactions enhance the chemostimulating activities of both oxides (a positive nonlinear effect takes place). The gas-phase interactions cause a marked negative deviation from the additive chemical stimulation effect The solid-phase interactions between the chemostimulators (during the evaporation of their mixtures) somewhat extend the lifetime of molecular oxide species in the vapor, giving rise to a positive thermal oxidation effect. The gas-phase interactions between the (chemostimulators are mainly dissociative. They reduce the chemostimulating effect and make a negative contribution to the nonlinear effects. The thin fi lms of the GaAs and InP surfaces synthesized using this method have better electrophysical properties and exhibit a gas-sensitive response in a reducing gases atmosphere.

The use of oxides as chemostimulators of AIIIBV thermal oxidation alters the mechanism of the process of thermal oxidation of semiconductors from its own to that of transit or catalytic. The mechanism of the process is determined by the chemical nature of the oxide-chemostimulator and the way it is introduced into the system (from the gas phase or deposition on the semiconductor surface). The oxides of p-metal (PbO, Sb2O3, Bi2O3), having redominantly one stable oxidation state, realize a transit mechanism of semiconductors oxidation, regardless of the way they are introduced into the system. The oxides of d-metals (MnO2, V2O5, CrO3) introduced through the gas phase act on the processes of thermal oxidation of GaAs and InP as the chemostimulator-transitors. The effect of nanosized NiO and Co3O4 layers in the processes of InP and GaAs thermal oxidation develops as a transit type, which is confi rmed by EEA values, which are of the same order of magnitude as the EEA of own oxidation of semiconductors, the consumption of oxide-chemostimulators with the passing of the process in time, a signifi cant decrease in the relative increase in fi lm thickness during the advanced stage of the process. For nanosized layers of vanadium oxide (V) the mechanism of their effect on the process of oxidation of AIIIBV is determined to a large extent by the deposition method (within the framework of one way). Thermal oxidation of AIIIBV under the infl uence of vanadium pentoxide layers deposited by soft methods implements the transit mechanism of the process, this is indicated by the expenditure of V2O5 in fi lms during thermal oxidation without subsequent regeneration. The catalytic nature of the effect of the magnetron-deposited (hard method) layers of V2O5 in the oxidation processes of InP and GaAs is confi rmed by a sharp decrease in EEA in comparison with the own oxidation of semiconductors and the independence of its value from the thickness of the deposited V2O5 layer, the cyclic regeneration of vanadium V5+ ↔ V4+, and the dynamics of the change in the relative increase in fi lm thicknesses. In this case, the processes of phosphate and arsenate formation take place at low temperatures (450-480 °C), an effective kinetic and chemical blocking of the diffusion of unoxidized indium into a fi lm occurs, and segregation of arsenic at the inner interface prevented. All of the above leads to a signifi cant improvement in the electrophysical parameters of the fi lms.

Abstract. Considered the problems that do not allow to fully realize the enormous potential of application of indium phosphide and gallium arsenide in solid-state electronics.The classical and modern results of the thermal oxidation of AIIIBV semiconductors with consideration of process stimulation by photon processing, magnetic pulses, etc. are analyzed and generalized. Particular attention is paid to the fundamental approach to solving the problem of the formation of nanoscale functional fi lms on AIIIBV, consisting in the use of reasonably selected chemical stimulators introduced into the system in various ways with the aim of changing the mechanism of the thermal oxidation process of semiconductors to chemical stimulated. This ensures the occurrence of new interface reactions with kinetically conjugated and heterogeneously catalytic stages, which in a single process allows: 1) to block the negative communication channel between the reactions of componentwise oxidation under thermal oxidation of pure AIIIBV; 2) acceleration of the fi lms formation in comparison with the process of pure AIIIBVoxidation, including branching through the products of the chemical stimulator conversion; 3) lowering the operating parameters of the process (temperature, time) and preventing degradation of the fi lms; 4) purposeful changes in the composition and properties of the nanoscale fi lms with the achievement of target characteristics. Deposited on the GaAs and InP surface nanoscale layers of d-metals (Ni, Co, and V) have a purposeful multifunctional effect on the composition and properties of the formed fi lms, changing the mechanism of the thermal oxidation of semiconductors from mechanism of pure AIIIBV oxidation to transit or catalytic. Effective kinetic and chemical blocking of the negative communication channel between the stages of pure InP and GaAs oxidationby used of a chemical stimulator prevents the diffusion of unoxidized indium into fi lms (0.3-0.5 % In versus 17 % native oxide, LE, XRD, IRS, USXRES data), segregation arsenic at the inner interface (the content of As in the form of As2O3, As2O5, [AsO4]3- increases 2-5 times XRD, IRS, and USXRES data) and provides the formation of nanoscale fi lms with semiconductor and dielectric characteristics (electrical strength up to 7 × 106 V/cm).

The article presents the research on interactions between phases in the Ge–Au, Ge–TiBx and Au–TiBxAu contacts to n–n+–n++-InP, both before and after rapid thermal annealing, and also the output parameters of Gunn diodes based on the InP structure with Au–TiBx–Au–Ge contact metallization in the –40...+60 °С temperature range. It is shown that ohmic contacts to InP layer are formed as a result of diffusion of Ge and Au atoms deep inside the layer. The output parameters of Gunn diodes with Au–TiBx–Au–Ge cathode contacts agree with the data obtained for InP Gunn diodes made with the use of more complicated technology.

It is experimentally confirmed that the temperature dependence of specific contact resistance of ohmic contacts Au—TiB2—Ge—Au—n—n+—n++-InP is described with the current transport model with a high density of dislocations in the contact region of the semiconductor. The samples used in the experiment were obtained at different annealing temperatures.

The paper studied the possibility of using nanostructures based on indium phosphide as a material for the manufacture of solar cells. The technology of obtaining textured p-InP surface. [ABSTRACT FROM AUTHOR]

The work describes the features of the band structure of deformed InP nanowires with different diameters. It is shown that the bending of quantum wires is capable of creating local minima in the conduction and valence bands which are separated from the surface of the cylindrical wire. This result opens up new possibilities for controlling both the lifetime of photoexcited carriers by keeping them at these minima and the magnitude of the photovoltage in solar energy conversion devices based on quantum wires. The work lies within a common goal aiming to develop new methods of functionalization of nanostructured surfaces using mechanical deformations. [ABSTRACT FROM AUTHOR]