Optical and Tribological Properties of PVD/CVD Diamond-like Carbon Films

The optical and tribological properties of diamond-like carbon (DLC) films deposited by the combination of magnetron sputtering of graphite and plasmochemical dissociation of methane were studied. It was established that at methane concentration in the gas mixture Ar/CH4 at about 5–10 % the formation of DLC films with refraction index n 2.0, microhardness larger than 1000 HK and friction coefficient of 0.06–0.08 becomes possible

Optical and Tribological Properties of PVD/CVD Diamond-like Carbon Films

The optical and tribological properties of diamond-like carbon (DLC) films deposited by the combination of magnetron sputtering of graphite and plasmochemical dissociation of methane were studied. It was established that at methane concentration in the gas mixture Ar/CH4 at about 5–10 % the formation of DLC films with refraction index n 2.0, microhardness larger than 1000 HK and friction coefficient of 0.06–0.08 becomes possible

Influence of the annealing temperature on the ferroelectric properties of niobium-doped strontium–bismuth tantalate

Characteristics of ferroelectric thin films of nio-bium-doped strontium–bismuth tantalite (SBTN), which were deposited by magnetron sputtering on Pt/TiO2/SiO2/Si substrates, are investigated. To form the ferroelectric structure, deposited films were subjected to subsequent annealing at 700–800°C in an O2 atmosphere. The results of X-ray diffraction showed that the films immediately after the deposition have an amorphous structure. Annealing at 700–800°C results in the formation of the Aurivillius struc-ture. The dependences of permittivity, residual polariza-tion, and the coercitivity of SBTN films on the modes of subsequent annealing are established. Films with residual polarization 2Pr = 9.2 μC/cm2, coercitivity 2Ec = 157 kV/cm, and leakage current 10–6 A/cm2 are obtained at the annealing temperature of 800°C. The dielectric constant and loss tangent at fre-quency of 1.0 MHz were ε = 152 and tanδ = 0.06. The ferroelectric characteristics allow us to use the SBTN films in the capacitor cell of high density ferroelectric random-access non-volatile memory (FeRAM)

Effect of Li+ doping on photoelectric properties of double perovskite Cs2SnI6: first principles calculation and experimental investigation

Double perovskite Cs2SnI6 and its doping products (with SnI2, SnF2 or organic lithium salts added) have been utilized as p-type hole transport materials for perovskite and dye-sensitized solar cells in many pieces of research, where the mechanism for producing p-type Cs2SnI6 is rarely reported. In this paper, the mechanism of forming p-type Li+ doped Cs2SnI6 was revealed by first-principles simulation. The simulation results show that Li+ entered the Cs2SnI6 lattice by interstitial doping to form strong interaction between Li+ and I−, resulting in the splitting of the α spin-orbital of I–p at the top of the valence band, with the intermediate energy levels created and the absorption edge redshifted. The experimental results confirmed that Li+ doping neither changed the crystal phase of Cs2SnI6, nor introduced impurities. The Hall effect test results of Li+ doped Cs2SnI6 thin film samples showed that Li+ doping transformed Cs2SnI6 into a p-type semiconductor, and substantially promoted its carrier mobility (356.6 cm2/Vs), making it an ideal hole transport material

Shape tailored Cu2ZnSnS4 nanosheet aggregates for high efficiency solar desalination

In this paper, the shape tailored high-purity kesterite phase Cu2ZnSnS4 (CZTS) nanosheet aggregates (NSAs) were prepared in a low cost one-pot solvothermal method, and further fabricated into a salt-blocking membrane for solar desalination. The designed CZTS NSAs membrane-based solar steam generation device featured high solar absorptivity, low thermal energy loss and long-term stability, achieving a remarkable water evaporation rate of 1.54 kg/m2h and solar steam conversion efficiency of 78.85%. It is noteworthy that the quality of artificial seawater desalinated by evaporation was better than that of distilled water, and organic dyes, in particular, could be degraded by nearly 100%. It indicates that the CZTS NSAs membrane is likely to be one of the greatest potential substitutes for seawater desalination as well as repurification of urban reclaimed water and chemical wastewater

Electron beam nitriding of titanium in medium vacuum

We describe a novel method for electron-beam nitriding of metal (titanium) under medium (fore-vacuum) pressures (2–8 Pa) of nitrogen. Titanium sample was heated by a dc electron beam generated by a fore-vacuum plasma-cathode electron source with current up to 100 mA and energy up to 8 kV; this beam also generated beam-produced plasma with active nitrogen atoms, ions and other reactive species near the sample. SEM chemical composition analysis of the nitride layer have shown the presence of approximately 25 wt% of N, wt. 68% of Ti and only wt. 6% of O atoms within the processed layer. The X-ray diffraction spectrum of the nitride sample showed that the modified layer has a crystalline structure predominantly orientated along the crystallographic directions (111), (200), (220), characteristic of δ-TiN with a face-centered lattice. Besides the δ-TiN phase, there are present in the nitrided layer a γ phase of Ti2N (tetragonal nitride) with predominant orientation (200). These results show the advantage of using forevacuum sources for electron beam and plasma nitriding of metals

Электрофизические свойства пленок оксида ванадия, нанесенных методом реактивного магнетронного распыления

The aim of this work was to study the effect of the gas composition during sputtering on the electrophysical properties of vanadium oxide films deposited by pulsed reactive magnetron sputtering of a vanadium target in an Ar/O2 medium of working gases.The dependences of the magnetron discharge voltage, deposition rate, resistivity, temperature coefficient of resistance (TCR), and the band gap of vanadium oxide films on the oxygen concentration in the gas mixture are obtained. It was found that amorphous films of vanadium oxide are formed during reactive magnetron sputtering. It is shown that the properties of the deposited vanadium oxide films have a strong dependence on the oxygen concentration in the Ar/O2 gas mixture, which is associated with the formation of a mixture of various intermediate vanadium oxides in the film. It was found that from the point of view of using vanadium oxide films as thermosensitive layers of microbolometers, the films must be deposited at oxygen concentrations in the gas mixture of 17 to 25 %. At the given oxygen concentrations without heating the substrates, vanadium oxide films with a resistivity (0.6–4.0)·10-2 Ohm·m, TCR 2.2–2.3%/°C and a band gap for direct transitions of 3.7–3.78 eV. The obtained characteristics make it possible to use these films as thermosensitive layers of microbolometers.Целью работы являлось исследование влияния состава газовой среды в процессе распыления на электрофизические характеристики пленок оксида ванадия, нанесенных методом импульсного реактивного магнетронного распыления ванадиевоaй мишени в среде Ar/O2 рабочих газов.Получены зависимости напряжения разряда магнетрона, скорости нанесения, удельного сопротивления, температурного коэффициента сопротивления (ТКС), ширины оптической запрещенной зоны пленок оксида ванадия от концентрации кислорода в смеси газов. Установлено, что при реактивном магнетроном распылении формируются аморфные пленки оксида ванадия. Показано, что электрофизические свойства нанесенных пленок оксида ванадия имеют сильную зависимость от концентрации кислорода в Ar/O2 смеси газов, что связано с образованием в пленке смеси различных промежуточных оксидов ванадия. Установлено, что с точки зрения использования пленок оксида ванадия в качестве термочувствительных слоев пленки необходимо наносить при концентрациях кислорода в смеси газов от 17 до 25 %. При данных концентрациях кислорода без нагрева подложек получены пленки оксида ванадия с удельным сопротивлением (0,6–4,0)·10-2 Ом·м, ТКС 2,2–2,3 %/°C и шириной запрещенной зоны для прямых переходов 3,7–3,78 эВ. Полученные характеристики позволяют использовать данные пленки в качестве термочувствительных слоев микроболометров

Модель процесса реактивного магнетронного распыления двухкомпонентной составной мишени

The article proposes a model for predicting the content of metal components of complex oxide films deposited by reactive magnetron sputtering of a two-component composite target in Ar/O2 gas mixture. The model takes into account the sputtering yield and ion-electron emission coefficients of the sputtered metals and their oxides, the distribution of the ion current density on the target, and the rate of the chemical reaction of the formation of oxides of these metals. To verify the proposed model, studies of the elemental composition of titanium-aluminum oxide films deposited by magnetron sputtering of a Ti-Al composite target in Ar and Ar/O2 gas mixture were carried out. It has been established that the model adequately describes the change in the content of metals in the deposited films with a change in the oxygen flow into the chamber. The simulation error does not exceed 10 %, this makes it possible to use the proposed model for predicting the content of metals in a film during reactive sputtering of two-component composite targets.В статье предложена модель для прогнозирования содержания металлических составляющих пленок сложных оксидов, наносимых методом реактивного магнетронного распыления двухкомпонентной составной мишени в среде Ar/O2 рабочих газов. В модели учитывались коэффициенты распыления и ионно-электронной эмиссии распыляемых металлов и их оксидов, распределение плотности ионного тока на мишени и скорости химической реакции образования оксидов этих металлов. Для верификации предложенной модели проведены исследования элементного состава пленок оксида титана-алюминия, нанесенных магнетронным распылением Ti-Al составной мишени в среде Ar и Ar/O2 рабочих газов. Установлено, что модель адекватно описывает изменение содержания металлов в нанесенных пленках при изменении потока кислорода в камеру. Погрешность моделирования – не более 10 %, что позволяет применять модель для прогнозирования содержания металлов в пленке при реактивном распылении двухкомпонентных составных мишеней

ФОРМИРОВАНИЕ ОБЪЕМНЫХ ВЫВОДОВ ПОЛУПРОВОДНИКОВЫХ ПРИБОРОВ МЕТОДОМ ЭЛЕКТРОХИМИЧЕСКОГО ОСАЖДЕНИЯ

Using nonstationary regimes electrolysis for electrodepositing silver solder bump semiconductor blocked has reduced lateral expansion of different height on the plate, to improve the qualitative characteristics of the product, increase the number of devices produced on a semiconductor wafer, and thereby improve process performance and achieve economies of precious metals.Исследовано влияние состава электролита и программируемых импульсно-реверсных режимов на скорость и равномерность формирования объемных серебряных выводов полупроводниковых приборов. Показано, что использование нестационарных режимов электролиза позволяет снизить их боковое разрастание и разновысотность по пластине, улучшить качественные характеристики изделий, увеличить количество приборов, получаемых на одной полупроводниковой пластине, и, тем самым, повысить производительность технологического процесса и обеспечить экономию драгметаллов

Анодная композиционная наноструктура: формирование, морфология, оптические и фотолюминесцентные свойства

Two-layer Al/Nb (1000/200 nm) was deposited by sputtering using a DC magnetron method on Si wafers. The anodizing was in 0.2 M oxalic solution at 53 V, re-anodized in the 0.5 M boric acid in potentiodynamic mode at increase of potential until 400 V. For forming anodic composite nanostructure, the porous anodic aluminum oxide was partially removed in 50 % aqueous solution of phosphoric acid at 50°C for 1200 s. The morphology, photoluminescence, and optical reflection of an anodic composite nanostructure were investigated. The anodic composite nanostructure showed effective optical reflection in the wavelength range from 540 to 1000 nm, and the maximum reflective efficiency was observed at a wavelength of 850 nm, 52 % reflectance occurs. The photoluminescence maximum was observed at a wavelength of 453 nm.Двухслойная система Al/Nb (1000/200 нм) на кремниевой подложке была проанодирована в 0,2 М водном растворе щавелевой кислоты при постоянном напряжении 53 В. После завершения этапа анодирования алюминия производили замену электролита на 0,5 М водный раствор борной кислоты и затем реанодировали подслой ниобия до напряжения 400 В. Для создания анодной композиционной наноструктуры проводили удаление большей части анодного оксида алюминия методом химического травления в течение 1200 с в 50 % растворе ортофосфорной кислоты при температуре 50 °С. Исследована морфология, фотолюминесценция, оптическое отражение анодной композиционной наноструктуры. Анодная композиционная наноструктура показала эффективное оптическое отражение в диапазоне длин волн от 540 до 1000 нм, а максимальная отражающая эффективность наблюдалась на длине волны 850 нм и составляет 52 %. Пик фотолюминесценции наблюдался на длине волны 453 нм.