The nucleation and growth of InSb nanocrystals formed at the Si/SiO2 interface of silicon-on-insulator structure, fabricated by bonding the Si and SiO2/Si substrates implanted with Sb+ and In+ ions, respectively, was investigated as a function of the annealing time at the temperature of 1100 degrees C. RBS, STEM, HRTEM, EDX, Raman and FTIR techniques were employed to analyze the In and Sb atom profiles, structural properties and the elemental composition of nanoparticles, as well as the optical phonons and the optical bandgap of InSb nanocrystals. The diffusion of In atoms from the SiO2 layer to Sb precipitates, formed in the top Si layer during the Sb atom segregation to the Si/SiO2 interface, was established. Cooling the InSb alloy with its subsequent crystallization results in the growth of hydrostatically stressed InSb nanocrystals in the Si matrix at the Si/SiO2 interface. As the annealing duration increases, the nucleation centers of InSb nanoparticles are formed at the Si/SiO2 interface, and a further nanocrystal growth occurs from the interface deep into SiO2. Despite the fact that the mismatch of the silicon and InSb lattices is 19 %, coincident Si[110]//InSb[001] and Si[110]//InSb[-114] directions were established for the interplane matching of InSb and Si lattices. The effect of the nanocrystal structure on the TO and LO phonon frequency was investigated as a function of the annealing time. From the FTIR analysis, the optical bandgaps of 0.43 and 0.31 eV were obtained for the InSb nanocrystals formed after the annealing time of 3-90 min, respectively.

Исследована фотолюминесценция в видимом спектральном диапазоне при комнатной температуре плёнок SiO2, имплантированных ионами In+ и As+ в зависимости от энергии ионов As+, температуры последующего отжига и длины волны возбуждающего излучения. Использовались ионы As+ с энергиями 40, 80 или 135 кэВ и ионы In+ с энергией 50 кэВ, при которых соотношение средних проективных пробегов ионов RpAs/RpIn составляло 1, 2 или 3 соответственно. Последующий отжиг проводился при температуре 900 и 1100 °C. Спектры фотолюминесценции возбуждались излучением лазера с длинами волн λ ex = 442 и 473 нм. В спектрах фотолюминесценции при возбуждении с λ ex = 473 нм наблюдался пик 550 нм, энергетическое положение которого смещалось к 520-530 нм при λ ex = 442 нм. Увеличение соотношения RpAs/RpIn сопровождалось уменьшением интенсивности фотолюминесценции, а также изменением соотношения интенсивности пиков в зависимости от температуры отжига. Наблюдаемый эффект обсуждается с точки зрения рекомбинации электронов и дырок в нанокристаллах InAs. The room-temperature visible photoluminescence of the In+ and As+ ion-implanted SiO2 films is investigated as a function of As+ ion energy, annealing temperature, and excitation wavelength. As+ ions at the energy of 40, 80, or 135 keV and In+ ions at the energy of 50 keV, providing an average range ratio RpAs/RpIn of 1, 2 or 3, respectively, are used. The subsequent annealing is carried out at a temperature of 900 and 1100 °C. The photoluminescence spectra are excited with a laser wavelength lex = 442 and 473 nm. The photoluminescence peak near 550 nm is obtained at an excitation wavelength of 473 nm. The wavelength position of this peak is shifted to 520-530 nm at lex = 442 нм. As the RpAs/RpIn ratio increases, the photoluminescence intensity drops down, and the photoluminescence intensity ratio as a function of the annealing temperature is changed. The resultant effect is discussed in the frame of the electron and hole recombination within InAs nanocrystals.

The visible room-temperature emission and excitation photoluminescence spectra were studied as a function of the indium and arsenic profiles in the In+ and As+ ion-implanted thermally grown SiO2 films before and after the annealing at the temperature of 900 degree celsius. As+ ions at the energy of 40 or 135 keV and In+ ions at the energy of 50 keV, providing a projective range ratio R-p(As)/R-p(In) of 1 or 3, respectively, were used. Four emission photoluminescence bands, peaked at similar to 347 nm (3.57 eV), similar to 440 nm (2.81 eV),similar to 450 nm (2.75 eV) and similar to 500 nm (2.48 eV), were obtained from the 40 keV As+ and 50 keV In+ ion-implanted samples under the excitation wavelength of 300 nm (4.13 eV), 350 nm (3.54 eV), 400 nm (3.10 eV) and 450 nm (2.75 eV), respectively. As the As+ energy increased to 135 keV, under the same excitation conditions, the emission bands peaked at 370 nm (3.35 eV), 420 nm (2.95 eV), 460 nm (2.69 eV) and 505 nm (2.45 eV) dominated in the photoluminescence spectra. The excitation spectra of the observed emission peaks were studied, too. We preliminarily interpret the observed photoluminescence peaks as a result of the T-1 -> S-0 transition of molecular-like clusters associated with the oxygen deficiency provided by In or In-As in ion-implanted SiO2.

The films of titanium nitride were deposited by direct current magnetron sputtering on the surface of singlecrystalline silicon samples in an Ar-N2 atmosphere for use as a diffusion barrier. The thickness and density of films were measured by X-ray reflectometry. The design of the MAGNA TM-200-01 installation has been changed to increase the supply of nitrogen into the chamber. The influences of sputtering conditions, including the flow rate of nitrogen and argon gases and their N2 /Ar ratios in the range of 1–60 in the chamber, magnetron power of 690–1400 W on the formation of TiNx films, their density and stoichiometric composition, were studied. It is shown that the value of x is affected not only by the N2 /Ar gas flow rate ratio, but also by the magnetron power. At the sputtering parameters 1200 W, N2 /Ar = 30, 0.8 Pa, 320 s and 100°C, a maximum density of 5.247 g/cm3 of a film was achieved, which corresponds to the composition TiN0.786 = Ti56N44. The presence of nanocrystalline film of titanium nitride and the absence of a nanocrystalline titanium phase were confirmed by photographic X-ray diffraction. It was found that for the synthesis of titanium nitride as close as possible to the stoichiometric composition TiN0.770 - TiN0.786, it is necessary to use magnetron power in the range of 900–1200 W, nitrogen rate of 30 cm3 /min with low argon flows of 1–5 cm3 /min.

The effect of annealing time on the InSb nanocrystal formation in a silicon-on-insulator structure, containing, near the Si/SiO2 interface, Si and SiO2 regions implanted with Sb+ and In+ ions, respectively, was studied. The annealing temperature was 1100 degrees C. A change in the nanocrystal growth direction was obtained as the annealing time increased from 1 to 90 min. After the 1 min annealing, the InSb nanocrystals grew within the Si matrix and were faceted. As the annealing time increased to 90 min, the nanocrystals grew from the Si/SiO2 interface into the SiO2 matrix; they had a half-spherical shape. A respective change in the phonon mode was observed, too. The origin of the obtained effect is discussed.

Visible photoluminescence from SiO _2 films implanted with In ^+ and As ^+ ions was studied at room temperature depending on the energy of As ^+ ions, the temperature of further annealing, and the exciting radiation wavelength. As ^+ ions with energies of 40, 80, or 135 keV and In ^+ ions with an energy of 50 keV, at which the ratio between the average projective ranges of ions R_p^As/R_p^In was 1, 2, and 3, respectively, were selected. Further annealing was performed at a temperature of 900 and 1100 ^∘ C. Photoluminescence spectra were excited with laser radiation with wavelengths λ_ex=442 and 473 nm. The spectra of photoluminescence under excitation with λ_ex=473 nm had a peak at 550 nm, whose energy position was shifted to 520-530 nm at λ_ex=442 nm. An increase in the ratio R_p^As/R_p^In was accompanied by a decrease in the photoluminescence intensity and a change in the ratio between the intensities of peaks depending on the annealing temperature. The observed effect was discussed from the viewpoint of recombination between electrons and holes in InAs nanocrystals.

The Raman spectroscopy and room-temperature photoluminescence were used to study the properties of the In+ and As+ ion-implanted SiO2 films as a function of annealing temperature Ta at 700-1100 degrees C. No features of the InAs phase were obtained in the Raman spectra of the native SiO2 films irrespective of Ta. In the ion-implanted SiO2 films encapsulated with Si3N4, three Raman peaks at 202 cm -1, 256 cm- 1 and 232 cm- 1 corresponding to transverse and longitudinal optical phonons in black As and to longitudinal optical phonons in InAs, respectively, were detected. The SiO2 encapsulation effect on the enhanced InAs phase formation is discussed. A photo-luminescence of around 556 nm was observed from the encapsulated ion-implanted SiO2 films and reached its intensity maximum after the annealing at 1000 degrees C.

Raman and photoluminescence spectra were investigated in the In+ and As+ ion-implanted SiO2 films encapsulated with Si3N4 layers as a function of annealing temperature. The optical phonon frequency, as a function of the InAs nanocrystal size, was also calculated within the confined phonon model. The Raman scattering band of around 231 cm-1, close to the low-frequency shifted longitudinal optical phonon mode in the InAs matrix, was observed as the annealing temperature increased to 900 degrees C. The InAs nanocrystal size of 3 nm was estimated. The strong room-temperature photoluminescence peaking at 550 nm (2.25 eV) was also obtained under the 473 nm wavelength excitation. Its intensity reached a maximum value as the annealing temperature increased to 1000 degrees C. Its peak position was blue-shifted as the excitation wavelength decreased. The direct irradiative electron and hole recombination in the InAs nanocrystals was proposed as a possible mechanism of this photoluminescence.

The high-resistance silicon layers were formed by the CO+ ion implantation of silicon substrates and a subsequent annealing at 1100 degrees C. The structural and electric properties of the ion-implanted layers were studied. The formation of 3C-SiC and 6H-SiC nanocrystals was obtained in the ion implanted layers. It was shown that the formation of SiC precipitates results in the positive charge compensation in the buried SiO2 layer of a silicon-on insulator structure. The origin of the obtained results is discussed.

The thermal stability of silicon-on-insulator films with a thickness of 4.7  and 2.2 nm is studied as a function of annealing temperature in the range of Т = 800–1200°C by scanning electron microscopy and spectral ellipsometry. No signs of film melting were found; the films remain continuous over this annealing temperature range. A decrease in the thickness of the films and a change in their phase composition with an increase in temperature are discovered. According to the data of spectral ellipsometry, as the annealing temperature is increased, the content of the crystalline phase in the films decreases and the content of the amorphous phase increases. The activation energy of the process of film amorphization is estimated. The revealed properties are discussed from the viewpoint of diffusion of oxygen atoms into a silicon film and rearrangement of Si–Si bonds.

The formation of InSb nanocrystals at the bonding Si/SiO2 interface of silicon-on-insulator structure was obtained as a result of the In and Sb atom diffusion from the ion-implanted SiO2 and Si regions, respectively, toward the interface. After the annealing at 1000 degrees C, the Raman scattering peaks corresponding to the transverse and longitudinal optical phonon mode in the monocrystalline InSb matrix were obtained. As the annealing temperature grew to 1100 degrees C, the transverse optical phonon mode vanished and the longitudinal optical phonon mode dominated in the spectrum. This effect is explained by matching InSb and Si lattice constants under ion beam synthesis conditions.

Изучена диффузия Ge из захороненного слоя SiO2 структуры кремний-на-изоляторе в зависимости от температуры отжига. Показано, что при температуре отжига ниже 900oC практически весь Ge сосредоточен в области имплантации в слое SiO2. После отжига при температуре 1100oC миграция ионно-имплантированного Ge сопровождается несколькими процессами: диффузией в SiO2, накоплением на границах раздела Si/SiO2, диффузией в кремний и испарением из кремния. При 1100oC диффузия Ge из SiO2 к границе сращивания структуры кремний-на-изоляторе происходит с коэффициентом диффузии ~ 2·10-15 см2/с, что на 2 порядка величины выше его равновесного значения. После отжига при 1100oC, в зависимости от толщины слоя кремния, обнаружено формирование фазы Ge или SiGe. Ключевые слова: SiGe, ионная имплантация, диффузия, кремний-на-изляторе.

The thermal stability of silicon-on-insulator films with a thickness of 4.7 and 2.2 nm was studied as a function of the annealing temperature in the range T = 800−1200◦ C by scanning electron microscopy and spectral ellipsometry. No melting features of the films were found. The films remained continuous over the annealing temperature range. A decrease in the thickness of the films and a change in their phase composition with an increase in temperature were found. According to spectral ellipsometry, as the annealing temperature increased, the content of the crystalline phase in the films decreases, and the content of the amorphous one increases. The activation energy of the film amorphization was estimated. The revealed properties are discussed in the frame of the oxygen atom diffusion in the silicon films and in the rearrangement of Si-Si bonds.

The Ge diffusivity from the buried SiO2 layer of silicon-on-insulator structure as a function of annealing temper- ature was studied. It was shown that at an annealing temperature below 900◦C, almost all Ge is localized in the implantation region in the SiO2 layer. As annealing temperature reached 1100◦ C, the migration of ion-implanted Ge is accompanied by several processes: diffusion in SiO2, accumulation at the Si/SiO2 interface, diffusion into Si as well as evaporation from silicon. The Ge diffuses from SiO2 to the bonding interface of the silicon-on-insu- lator structure with the diffusion coefficient of ∼ 2 · 10−15 cm2/s that is two orders of magnitude higher than its equilibrium value. Depending on the thickness of the silicon layer, the formation of the Ge or SiGe phase after annealing at a temperature of 1100◦C was detected.

Термическая стабильность пленок кремний-на-изоляторе толщиной 4.7 и 2.2 нм исследовалась в зависимости от температуры отжига в интервале T=800-1200oС методами сканирующей электронной микроскопии и спектральной эллипсометрии. Никаких признаков плавления пленок не наблюдалось, пленки оставались протяженными в указанном интервале температур. Обнаружено уменьшение толщины пленок и изменение их фазового состава с ростом температуры. По данным спектральной эллипсометрии, с увеличением температуры отжига доля кристаллической фазы в пленках уменьшается, а доля аморфной растет. Определена энергия активации процесса аморфизации пленок. Обнаруженный эффект обсуждается с точки зрения диффузии атомов кислорода в пленку кремния и перестройки Si-Si-связей. Ключевые слова: кремний-на-изоляторе, термическая стабильность, наноструктуры, аморфизация.

Ge diffusivity from a buried SiO2 layer of a silicon-on-insulator (SOI) structure has been studied as a function of annealing temperature. It has been shown that, at an annealing temperature lower than 900°C, almost all Ge is localized in the implantation region of the SiO2 layer. As the annealing temperature is raised to 1100°C, migration of ion-implanted Ge is accompanied by several processes: diffusion into SiO2, accumulation at Si/SiO2 interfaces, diffusion into silicon, and evaporation from silicon. At 1100°C, Ge diffuses from SiO2 to the bonding interface of the SOI structure with the diffusion coefficient of ~2 × 10−15 cm2/s, which is 2 orders of magnitude higher than its equilibrium value. Depending on the thickness of the silicon layer, formation of a Ge or SiGe phase is detected after annealing at a temperature of 1100°C.

The diffusion of indium atoms in silicon-dioxide films previously implanted with arsenic ions with different energies is studied in relation to the temperature of postimplantation annealing. It is established that the diffusion properties of indium depend on the presence of arsenic atoms in the film and their energy. An increase in the As content in the region of the average projective range of In+ ions prevents the diffusion of In towards the SiO2 film surface at high annealing temperatures and stimulates the diffusion of In deep into the film in the form of a monovalent interstitial site. The experimentally observed effects are interpreted on the assumption of the formation of In–As pairs in neighboring substitutional positions in the SiO2 matrix.

In this paper, we examine carrier transport mechanisms in Silicon-on-Insulator (SOI) structures, containing InSb nanoparticles in SiO2 layer, before and after annealing at 1273 K. The comparison of temperature dependences of current-voltage (I-V) characteristics allowed us to determine the mechanisms of carrier transport (hopping and zonelike) in this nanostructures and estimate some transport parameters in the temperature range of 2-300 K. The measurements have confirmed the presence of Fouler-Nordheim and hopping mechanism contributions into lowtemperature I-V characteristics of the studied SOI structures.

Интерес к созданию и изучению нанокристаллов InSb на основе кремния обусловлен необходимостью создания гибридных интегральных схем, объединяющих в себе элементы с различными функциональными свойствами. Локализация оптических фононов в кристаллах с пониженной размерностью может оказывать влияние как на оптические, так и на электрические свойства этих кристаллов. В данной работе проведен сравнительный анализ свойств оптических фононов в нанокристаллах InSb, ионно-синтезированных в решетке Si, а также в нанокристаллах InSb в пленках SiO2, созданных методами ионно-лучевого синтеза и радиочастотного магнетронного распыления. Свойства оптических фононов в нанокристаллах InSb объяснены с точки зрения влияния структурных свойств окружающей матрицы. Ключевые слова: InSb, кремний, оксид кремния, нанокристаллы, синтез.

Разработаны физические основы технологии создания структур «кремний на изоляторе» с захороненным high-k-диэлектриком нанометровой толщины методом водородного переноса. Продемонстрированы возможности создания двухзатворных пьезоэлектрических транзисторов на основе созданных структур.