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This work is devoted to the development of a technique for obtaining an array of multi-walled vertically aligned carbon nanotubes (VACNT) with a thickness of up to 120 μm on Si/Al2O3/Fe substrates and to the study of their absorbing properties in the THz spectral region, as well as to the assessment of their prospects as a broadband THz radiation absorber based on calculations of the spectral dependence of absorption coefficient for traditional and inverted-type bolometric devices. It is shown that the absorption of the VACNT array transferred onto the Revalpha polymer substrate reaches 70–80% in the wavelength range of 40–200 µm. Calculations show that traditional bolometers with an absorber based on VACNT have the best sensitivity at wavelengths less than 100 μm, and inverted bolometers also having a VACNT layer have the best sensitivity at wavelengths exceeding 50 μm, which makes them complementary to each other.

The results of recent studies of the structural morphological transformations of Si(111) and Si(100) surfaces using in situ ultrahigh-vacuum reflection electron microscopy (UHV REM) are presented. It is established that high-temperature sublimation from extremely wide Si(111) terraces occurs at a smaller activation energy (3.77 eV) than from the vicinal surface (4.04 eV). A nonmonotonic change in the kinetics of step bunching during a smooth transition from sublimation to growth on the Si(100) surface is recorded. The structural transformations caused by electromigration of positively charged Sn adatoms on the reconstructed Si(111) surface are demonstrated. It is shown that Si(111) surface etching under exposure to a Se molecular beam occurs in a layer-by-layer mode due to the desorption of SiSe2 molecules with activation energy of 2.65 eV.

The article presents how the understanding of the fundamental processes of self-organization and morphological transformations of the atomically clean Si(111) surface as a result of the study using in situ ultrahigh vacuum reflection electron microscopy can be applied to metrology. The method of high-resolution transmission electron microscopy is used to show that the native oxide formed on the Si(111) surface in atmospheric conditions replicates the atomic step height with high accuracy. The techniques for creating vertical measures in the range 0.31–31 nm with an error of less than 0.05 nm in the entire measurement range are developed on this basis. It is shown that it is possible to create extremely wide atomically smooth surfaces (up to 230 $$\mu$$ m) and use them as reference mirrors in interferometric microscopes. Crystal samples containing a certain number of monoatomic steps and atomically smooth surface areas are included in the State Secondary Reference Standard as a measure of angstrom height and angstrom flatness.

Using in situ ultrahigh vacuum reflection electron microscopy, three modes of the etching kinetics of the Si(111) surface with a selenium molecular beam are revealed. In the low temperature region ( $$\lesssim$$ 650 $${}^{\circ}$$ C depending on the Se deposition rate), the etching kinetics is limited by the energy of formation and desorption of SiSe $${}_{2}$$ molecules and the surface is completely covered by an impurity-induced silicon selenide phase ‘‘1 $$\times$$ 1’’-Se. In the temperature range $${\sim}700{-}1100^{\circ}$$ C the etching rate is limited by the amount of Se deposition flow and does not depend on the temperature, surface structure, and etching mechanism (step-layer or two dimensional-island). At high temperatures ( $${\gtrsim}1150^{\circ}$$ C), the sublimation of Si atoms begins to make the main contribution to the silicon flux from the surface. A theoretical model describing the temperature and kinetics of transitions between etching modes is formulated.

In the present work, the low-fluence nonablating femtosecond laser irradiation (λ = 800 nm) of the GeO2 layer with Ge nanoclusters protected by SiO2 layers is studied by different types of microscopy (optical microscopy, atomic force microscopy, and scanning and transmittance electron microscopy) and Raman spectroscopy. After the laser modification, the multilayer thickness increased by 6%–29% depending on the laser fluence. It was found that the laser fluence of ∼40 mJ/cm2 was the optimal value for observing the swelling effect and was below the ablation threshold. Irradiation at this fluence led the Ge nanoclusters to decrease in size from 5–8 to ∼2 nm and crystallize, while the GeO2 matrix expanded due to the formation of GeO bubbles. The fabrication mechanism of the novel type of nanofoam consisting of a glassy matrix, cavities filled with gas, and semiconductor nanocrystals with reduced size dispersion is discussed. Presumably, this effect is associated with the selective absorption of IR (800 nm) laser radiation by Ge nanoclusters.

The dislocation structure of diamond crystals grown in the Mg-Si-C system at pressure of 7.0–7.5 GPa and temperature of 1800 °C was studied by selective etching. We determined the dislocation density and identified individual features of etching for the growth sectors of {111} and {100} faces. On the {111} faces, all etch pits formed at the outcrops of different dislocations were found to be identical. The feature of grown diamond crystals is the presence of numerous large dislocation loops in the {100} growth sectors. The identified patterns of crystals etching and the internal crystal structure features are associated with the presence of a silicon impurity in the grown diamonds.

This article reports a study of the morphology of diamond crystals grown at 7.0 GPa and 1800 °C in the Mg-C system with the addition of silicon in an amount of 0.5 wt%. Step patterns on {111} and {100} faces were studied in a wide range of magnifications using optical microscopy (DIC), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Morphological studies revealed that a reduction in the growth rate and a change in the morphological significance of the {100} and {111} faces were associated with adsorption of a mobile impurity (silicon) leading to poisoning of kinks and (or) steps. This leads to roughing of the faces and formation of macrosteps as well as 2D and 3D nucleation islands. At a silicon concentration of 1.0 wt% or more, immobile impurity particles are apparently formed on macrostep terraces, and growth inhibition occurs according to the Cabrera-Vermilyea model.

The process of local anodic oxidation of thin GeO films has been studied using an atomic force microscope. The electron-probe microanalysis showed that oxidized areas of a GeO film were germanium dioxide. The effect of the voltage pulse duration applied to the probe–substrate system and the atmospheric humidity on the height of the oxide structures has been studied. The kinetics of the local anodic oxidation (LAO) in a semi-contact mode obeys the Cabrera–Mott model for large times. The initial growth rate of the oxide (R0) significantly increases and the time of starting the oxidation (t0) decreases as the atmospheric humidity increases by 20%, which is related to an increase in the concentration of oxygen-containing ions at the surface of the oxidized GeO film. It was shown that nanostructures in thin GeO layers can be formed by the LAO method.

A technique for reversible surface modification with an atomic-force-microscope (AFM) probe is suggested. In this method, no significant mechanical or topographic changes occur upon a local variation in the surface potential of a sample under the AFM probe. The method allows a controlled relative change in the ohmic resistance of a channel in a Hall bridge within the range 20–25%.

Modern lithographical methods used to create linear measures for nanometer-range dimensions and the main factors which limit the applications of such gages have been analyzed in the paper. Prospects for developing high-precision measures based on an atomically structured crystalline surface (containing monoatomic steps) whose parameters are bound to the crystallographic parameters of the crystal (traceable to the length measure) are shown. A method which can be used to create such measures based on controlling the surface morphology of monocrystalline silicon at an atomic level due to the effects of self-organization arising at the atomically clean surface as a result of annealing in ultrahigh vacuum is proposed. A description of the set of high-precision gages of vertical dimensions STEPP-IFP-1 in a size range of 0.31–31 nm with an error in the whole interval of gages of less than 0.05 nm is presented. The set of high-precision gages after carrying out state testing is included into the state registry of measuring means as measuring type no. 48115-11 (Federal Agency on Technical Regulating and Metrology order no. 6290 of October 31, 2011).

The effect of the electrolyte composition on the surface morphology and the dispersion dependences of the refractive index and extinction coefficient of ∼20-nm-thick anodic layers on InAs (111)III substrates is studied by atomic force microscopy and spectral ellipsometry. It is shown that oxidation in electrolytes with different acidities does not modify the surface morphology of the initial InAs substrates. The films formed upon oxidation exhibit close dispersion dependences, despite the difference in the chemical composition between the films. This makes possible the high-precision monitoring of the thickness of anodic layers on InAs substrates by means of ellipsometry with the optical model of a single-layer isotropic film on an absorbing substrate.

Various semiconductor devices created by molecular beam epitaxy and lithography were numerically modeled: a quantum point contact in the voltage gate-induced two-dimensional electron gas, a versatile tunable two-terminal quantum dot, a small three-terminal quantum dot, and ring interferometers. Three-dimensional electrostatics calculations, taking into account the design of structures, combined with the theories of Coulomb blockade and quantum ballistic transport, allowed explanation of the observed resistance features of nanodevices. Accumulated experience was used to design semiconductor artificial graphene.

In this chapter the ability to study atomic processes on the Si surface during sublimation, growth, oxygen etching, and gold adsorption by in situ ultrahigh vacuum reflection electron microscopy (a unique method developed in ISP SB RAS) are reviewed. Using this technique, a surface instability called the step-bunching phenomenon was discovered previously, it is however, still poorly understood due to many unknown parameters of adatom/advacancy step interactions. Observation of gold adsorption induced step-bunching depending on an annealing time at a temperature of T =900°C suggests that a surface-bulk defect exchange is also involved in the formation of instability. The dynamics of two-dimensional vacancy island formation on 120-µm step-free terraces shows that sublimation is defined by adatom detachment from steps up to a critical temperature of T crit ~1180°C, while adatom diffusion length falls from ~55 (970°C) to ~7 µm due to recombination with the vacancies. At T crit >1180°C, sublimation is dominated by the straightforward evaporation of surface atoms reserving vacancies that interact with steps. From the studies of Si growth on the step-bunched Si(111)-(7×7) surface, a crucial role of step permeability in 2D island nucleation and growth (2DNG) kinetics has been revealed. Step permeability is a key factor in pyramid-like growth on terraces exceeding the critical width for 2DNG. We show that quantitative parameters of adatom/vacancy diffusion and their interactions with steps (Schwobel barriers) can be determined.

“Step-and-terrace” surface morphology, with regular arrays of atomically flat terraces separated by monatomic steps was obtained by annealing GaAs(001) substrates in conditions close to equilibrium. The closeness of annealing conditions to equilibrium was determined by experiments on samples with lithographic marks. The annealing kinetics are characterized by full-length monatomic steps, and also by Fourier and autocorrelation analyses. A comparison of the experiment with Monte Carlo simulation enabled us to elucidate the main stages and microscopic mechanisms of the step-terraced morphology formation, and to evaluate the effective parameters which determined this process. The formation of straight dislocation-induced steps of monatomic height were studied under thermo-mechanical stress relaxation in GaAs/AlGaAs heterostructures bonded to glass.

The operating principles of subminiature semiconductor emitters are formulated in this chapter, and the research results of the performance for those emitters that have been developed and manufactured at the SB RAS Institute of Semiconductor Physics for the last 5 years are given. The results of developing single-mode vertical cavity surface emitting lasers with a wavelength of 795 nm future-oriented for application in a chip scale atomic clock operating at a transition of 5S1/2→5P1/2 of Rb87 atoms are reported, as well as the results of developing a fully semiconductor Bragg microcavity for single-photon emitters. The latter combines current pumping selectively positioned InAs quantum dots, high external quantum efficiency, and a low level of output radiation divergence.

A possibility of using a new method of film synthesis in a supersonic flow of a hydrocarbon plasma generated by a disk-type magnetohydrodynamic accelerator is demonstrated. Two methods are used for characterization of diamond-like carbon films: nondestructive spectroscopic ellipsometry and atomic-force microscopy.

The precision of measurements performed by atomic-force microscopy (AFM) and high-resolution electron microscopy (HREM) for solving problems of metrology and diagnostics of solid nanostructures is discussed. The HREM-measured height of a monatomic step on a Si(111) surface covered by a thin natural oxide film is demonstrated to be 0.314 ± 0.001 nm. The same accuracy is ensured by AFM measurements through controlling the Si surface relief with heating in ultra-high vacuum on specially created test objects with the distance between the steps being approximately 2 µm. It is shown that the geometric phase method can be used to quantify the strains in the crystal lattice of strained heterostructures on the basis of HREM images with accuracy to 10−4%, and in situ irradiation by electrons in HREM measurements can be used to visualize ordered clusterization of vacancies and self-interstitial atoms in {113} planes in Si samples.

The possibility of forming the Ge-based wires with the nanoscale’s lateral resolution using the local modification of GeO(sol) films by a scanning probe microscope was demonstrated for the first time. The property of the solid germanium monoxide films, namely, their metastability, was used to decompose the GeO film on Ge and GeO2 by running the high-density electric current under the probe of the atomic force microscope.

In this work we revealed correlation between presence of surface defects and peculiarities in ellipsometric spectra and hence in optical properties of AlN films grown by ammonia MBE technique. We propose to use this fact for the fast and non-destructive checking of film quality. Principal criterions of AlN films quality was both magnitude of phase deviation in maximum and/or a value of false (effective) absorption in transparency field of AlN calculated in according with our model. Our experiments were based on using of spectroscopic ellipsometry (SE). Atomic force microscopy (AFM) was used for determination of geometric size of overlayer roughness. Quantitative parameter related with surface morphology γs was proposed and influence of surface defects upon phase of light reflected was studied to evaluate surface quality from ellipsometric spectra at once, i.e. without any model calculations. Besides, an impact of surface defects upon film extinction coefficient is demonstrated in case when roughness is not taken into account. This approach could be useful for sorting identical films produced in routine growth procedure.

The mechanism of the formation of phase contrast in atomic force microscopy (AFM) is studied for various conditions of an oscillating tip interacting with the surface. A phase shift is detected in oscillations of the resonating AFM tip during its interaction with the substrate surface when the AFM tip moves over the surface. We substantiate kinetic mechanism of the formation of phase contrast in AFM, which is initiated when the velocity of the AFM tip moving over the substrate surface increases as a result of increasing friction force. A dependence of the kinetic contrast in AFM on the effective roughness of the surface is discovered. Images of the distribution of copper impurity over the silicon surface under atmospheric conditions are obtained using the method of kinetic phase contrast in AFM.

A study of the surface structure and electronic properties of (010) KGd0.95Nd0.05(WO4)2 (Nd:KGW) using RHEED analysis and XPS is presented. It is shown that Nd doping has a negligible effect on the core levels of the basic elements. A bombardment of the Nd:KGW crystal with 3-keV Ar ions results in surface amorphization accompanied by the generation of tungsten ions in lower valence states.

In the present work we study the electron transport properties of small (≈ 100 nm) ring interferometers fabricated by the local anodic oxidation of a AlGaAs / GaAs heterostructures containing 2D electron gas. Owing to the small size of the rings the Aharonov-Bohm (AB) oscillations in them can be observed at temperatures as high as 9 K. It has been found that the temperature dependence of AB oscillations amplitude in these rings is sensitive to the modification of the microscopic potential realization resulting from thermal recycling of the structure.

Small-radius (110 nm) ring interferometers were fabricated by the local anodic oxidation of AlGaAs/GaAs heterostructures containing 2D electron gas. Measurements and modeling show that a small ring asymmetry, which is detected by an atomic force microscope, leads to a small amplitude of Aharonov-Bohm oscillations, while a stronger asymmetry completely suppresses these oscillations.

Atomic force and reflection electron microscopes have been applied to investigate tip-induced local anodic oxidation of the titanium and silicon films. The number of parameters such as applied voltage, oxidation time, relative humidity and host material was under consideration. The special treatments were applied to reduce the roughness of the studied surfaces achieving the average roughness of the surface less than one angstrom. Some examples of nanostructures fabrication are demonstrated.

Peculiarities of the fabrication of field effect transistor (FET) at nanoscaled size on ultrathin silicon-on-insulator (SOI) was studied in details. Two types of FET transistor were successfully realized: in-plane-gate FET (IPGFET) with 40 nm minimum channel size and multichannel top-gate MOSFET on silicon-on-insulator. The deep submicron top-gate of Ti/Au embraces each of the conductive oxidized silicon wires placed with 400 nm pitch. The type and concentration of carries in a conductive channel of the ultrathin SOI was controlled by a bottom gate. The fabricated transistors demonstrated high transconductance and low threshold voltage. Some results of electron properties of the nano-FET transistors are presented.

Morphology and crystallographic characteristics of (001) KTiOPO4 air-annealed surface were investigated. The autoepitaxy of nanosized KTiOPO4 islands was revealed in samples annealed at 550°C for 2–20 h. When annealing at 650°C takes ∼20 h, the TiO2 particles are observed to form on the substrate surface. This indicates the onset of the thermal decomposition of KTP at this temperature.

Oscillations of the magnetoresistance commensurate with the spatial modulation period of the growth surfaces were observed in selectively doped GaAs quantum wells with AlAs/GaAs superlattice barriers grown by molecular beam epitaxy. The experimental data obtained are explained by the lateral potential modulation of the two-dimensional electron gas in narrow GaAs quantum wells with corrugated heteroboundaries and agree with the two-dimensional distribution of the local capacitance in such structures.

The topmost surface of crystal during Ti-indiffused LiNbO 3 waveguide preparation was studied using atomic force microscopy and high energy electron diffraction. The formation of the flat terraces with high step ∼0.24 nm as a result of high temperature annealing has been detected. The global changing of surface morphology induced by Ti diffusing was observed. No new phase formation on the surface was detected.

The method to change surface potential by atomic force microscope (AFM) probe is demonstrated and used. The possibilities of two dimensional electron gas reversible modulations are demonstrated on the example of nanoscale local AFM tip-induced surface nanomodification of heteroepitaxial AlGaAs/GaAs. The surface potential modulation is shown to be 100 mV with sample resistance change being 20–40 KOhm. Surface potential change is detected by Kelvin Scanning Probe Microscopy (KSPM).

Decomposition of germanium monoxide (GeO) films under the impact of an atomic force microscope (AFM) tip was observed for the first time. It is known that GeO is metastable in the solid phase and decomposes into Ge and GeO(2) under thermal annealing or radiation impact. AFM tip treatments allow us to carry out local decomposition. A novel tip-induced local electrical decomposition (TILED) method of metastable GeO films has been developed. Using TILED of 10 nm thin GeO film, Ge nanowires on silicon substrates were obtained.

Tip‐induced local anodic oxidation on Ti, GaAs and Si films surfaces in ambient conditions is presented. Oxide patterns on smooth Ti, GaAs and Si surfaces were obtained. The thickness of the oxide layer is studied as a function of the applied probe‐sample voltage and the velocity of the tip. To reach the best resolution, the extremely flat silicon surfaces were prepared in an UHV chamber of electron microscope by using electromigration effect. The average roughness of surfaces was less than 1 angstrom. Tip‐induced direct nanoscratching on GaAs surfaces is presented. The depth of the nanocuts is studied as a function of the applied tip‐sample extra force. An example of nanofabricated oxide patterns for a nanoelectronic device is presented.

The topmost surface of crystal during Ti-indiffused LiNbO/sub 3/ waveguide preparation was studied using atomic force microscopy and high energy electron diffraction. The formation of the flat terraces with height step /spl sim/0.24nm as a result of high temperature annealing has been detected. The global changing of surface morphology induced by Ti diffusing was observed. No new phase formation on the surface was detected.

Availability of self-assembly effects occurring at the atomically clean Si(1 1 1) surface during high temperature anneals in an ultrahigh vacuum chamber for fabrication of a precise calibrator at nanoscale measurements is discussed. These effects provide formation of ordered monatomic step arrays assembled by step bunches divided by almost singular surface areas with widely spaced monatomic steps suitable for calibration of atomic force microscopes. The monatomic step height at the Si(1 1 1) surface and its replication by the native oxide layer was attested by the high-resolution transmission electron microscopy followed by Digital Micrograph analysis and found to be equal to interplanar spacing (0.314 nm) in the volume of Si crystal with ±0.001 nm of accuracy. Excellent replication of the monatomic step height by oxide film covering the Si surface makes available precise AFM calibration at the nanoscale at ambient conditions. The averaged step height measured by AFM scanning of 1 × 1 µm2 is found to be 0.314 ± 0.003 nm (~1% of uncertainty). However, when the scan area becomes bigger than 2 × 2 µm2, the height measurement uncertainty increases sharply 15 times (0.310 ± 0.034 nm). We assume that this is due to differences between piezo element calibrations at small and large scan areas. The height measurement uncertainty for step bunches with well-defined quantity of steps (28) even at a large scan area (18 × 18 µm2) turns out to be 0.3%.

The temperature dependence of the Aharonov-Bohm oscillations of small quasi-ballistic ring interferometers (effective radius R = 90–110 nm) is studied in a wide temperature range of (0.34–9) K. It is found that this dependence is determined not only by the size of the interferometer, but also by its microscopic state. It is shown that the effect may be associated with the influence of the fluctuation potential leading to different, but not completely stochastic, realizations of the scattering potential in conducting channels of the ring.