The method of forming germanium nanoislands on vicinal silicon surfaces
Usage: in the field of nanoelectronics to create on the basis of structures nanostream (quantum dots) germanium on silicon semiconductor devices with ultra-high performance, as well as some of optoelectronic devices. The inventive method of forming germanium nanoislands on vicinal silicon surfaces is that the annealing vicinal si substrate at the stage precipitaciones training and during deposition Germany is produced by passing constant current in the direction perpendicular to the front steps of the vicinal faces of the silicon. The technical result of the invention is the formation of high-density highly organized and committed by the structure of the arrays of germanium nanoislands on vicinal silicon surfaces (III). 2 Il. The invention relates to the field of nanoelectronics and can be used to create on the basis of structures nanostream (quantum dots) germanium on silicon semiconductor devices with ultra-high performance, as well as some of optoelectronic devices.The most promising method of forming structures with nanotron the effect of self-organization of surface in heteroepitaxial systems due to the relaxation of elastic stresses, due to the mismatch of the parameters of crystal lattices of the film and substrate. For the system silicon-germanium samoformiruyushchikhsya the germanium nanoislands are characterized by relatively large lateral dimensions, which does not allow to fully manifest the effects of size quantization in such structures. In addition, localization of Islands in the plane of the heterojunction has a random character. Reducing the size of the Islands is generally achieved through the use of low temperatures of the substrate during deposition of the film Germany, which degrades the crystalline perfection of self-organizing nanostruc and increases their heterogeneity in size. Examples of the effect of DC to influence the size and the degree of ordering of nanostruc in the system silicon-germanium is unknown to us.In the formation of structures with germanium nanoislands on silicon is typically used following sequence of technological operations (see, for example, N. In. Vostokov, S. A. Gusev, I. C. Debts etc./FTP, T. 34, vol. 1, S. 8-12 (2000); O. P. Pchelyakov, Y. B. Bolkhovityanov, A. C. dvurechensky and other TEKHN, T. 34, vol.11, S. 1281-1299 (2000)): 1) to create an atomically clean surface Albom the flux of atoms of silicon in ultrahigh vacuum conditions; 2) is grown buffer layer of silicon of a thickness of 20-200 nm; 3) next, the substrate with the indirect source is heated to a certain temperature (usually 200-700oC), which will be deposited film Germany; 4) deposition of the film Germany effective thickness of from 3 to 15 monoatomic layers (1 ML =0.14 nm) at a rate of film growth is from 0.01 to 0.05 nm/s; 5) in some cases is more (pokerstove) annealing of the crystals after the deposition of Germany at the temperature of the substrate 500-700oFrom within 3-30 minutesFormed through the self-organization of the surface of the germanium nanoislands have the following major drawbacks: 1) at relatively high temperatures of the substrate during deposition Germany (500-700oC) samoformiruyushchikhsya Islands are characterized by large lateral dimensions (150-300 nm), significantly greater than the wavelength of de Broglie for this system that does not allow you to manifest the effects of size quantization in data structures; 2) reduce the size of the Islands can be achieved through the use of low temperatures of the substrate during deposition of the film Germany (200-300oC). However, the nature of the surface morphology is determined by kineticenergy islets in size; 3) and in the first and in the second case, the localization of the Islands in the plane of the interface film-substrate has a random character.The present invention is the formation of high-density, highly organized and committed by the structure of the arrays of germanium nanoislands on a vicinal surface of si (111).This object is achieved due to the fact that the heating vicinal si substrate is produced by passing constant current in the direction perpendicular to the front steps of the vicinal faces of silicon.In Fig. 1 shows the AFM image of the topography of the structure with germanium nanoislands on the surface of the silicon (111) formed in the following manner: a silicon substrate mark KES - 0.01 (111), which is a rectangular strip of 0.3415 mm, with double misorientation from the original plane was placed in a vacuum chamber. After reaching the working vacuum cleaned surface of the silicon layer from the natural oxides and inclusions of silicon carbide two-minute annealing of crystal direct transmission of direct current in the direction of the lower terraces (Fig.2) at a temperature of 1250oher but, on the contrary, the surface roughness was smoothed out. Further, the direction of the current was reversed and it was a 30-second annealing the crystal at a temperature of 1220oWith the aim of forming a stepped structure of the substrate. Then, by reducing the density passed through the sample DC (reducing the intensity of the electric field E is applied to the sample), the temperature of the substrate was lowered to 500oWith and produced coating film Germany with an effective thickness of close to 6 ML (0,9 nm) at a growth rate of 0.05 nm/s with further pokerstove annealing DC for 10 minutes. As a result, the surface of the formed system of highly ordered germanium nanoislands, built strictly along the front of nanostore substrate. The dimensions of the base of the Islands does not exceed 30 nm, the density of the islets close to 11011cm-2.The effect of ordering nanostruc is due to the fact that: 1) the deposition of Germany is on the shaped substrate, on which nanostore formed as a result of annealing of the crystal by passing constant current in the direction perpendicular FR is a major deviation from the original plane, annealing which leads to the formation of the steps with a sawtooth geometry of the front. Sawtooth edges formed steps in the future are centres of fixing adatoms Germany, forming nanostruc;
3) to enhance the directional flow of adatoms on the stages of the deposition film and pokerstove annealing is used, the effect of direct current (electromigration), builds nanostruc besieged Germany along the front of nanostore substrate.The use of the proposed method of forming germanium nanoislands on vicinal silicon surfaces provides in comparison with existing methods the following benefits:
1) makes it possible to obtain spatially ordered arrays of nanostruc high density;
2) allows to obtain the small islets at a relatively high temperature of the substrate (500oC), which reduces the likelihood of defects in the crystal structure in such objects.
The method of forming germanium nanoislands on vicinal silicon surfaces, which consists in annealing in vacuum silicon substrate (III) with a double misorientation from iact by passing a constant current perpendicular to the front steps of the vicinal faces of silicon in the direction providing the unevenness of the surface, subsequent annealing the silicon substrate at the change of current direction on the opposite for forming a stepped structure, temperature reduction, spraying, Germany, followed pokerstove annealing DC.
FIELD: semiconductor technology; production of microelectronic devices on the basis of substrates manufactured out of III-V groups chemical element nitride boules.
SUBSTANCE: the invention is pertaining to production of microelectronic devices on the basis of substrates manufactured out of III-V groups chemical element nitride boules and may be used in semiconductor engineering. Substance of the invention: the boule of III-V groups chemical element nitride may be manufactured by growing of the material of III-V groups the chemical element nitride on the corresponding crystal seed out of the same material of nitride of the chemical element of III-V of group by epitaxy from the vapor phase at the speed of the growth exceeding 20 micrometers per hour. The boule has the quality suitable for manufacture of microelectronic devices, its diameter makes more than 1 centimeter, the length exceeds 1 millimeter, defects density on the boule upper surface is less than 107 defects·cm-2.
EFFECT: the invention ensures manufacture of the microelectronic devices of good quality and above indicated parameters.
102 cl, 9 dwg
FIELD: non-organic chemistry, namely triple compound of manganese-alloyed arsenide of silicon and zinc arranged on monocrystalline silicon substrate, possibly in spintronics devices for injection of electrons with predetermined spin state.
SUBSTANCE: electronic spin is used in spintronics devices as active member for storing and transmitting information, for forming integrated and functional micro-circuits, designing new magneto-optical instruments. Ferromagnetic semiconductor hetero-structure containing zinc, silicon, arsenic and manganese and being triple compound of zinc and silicon arsenide alloyed with manganese in quantity 1 - 6 mass % is synthesized on substrate of monocrystalline silicon and has formula ZnSiAs2 : Mn/Si. Such hetero-structure is produced by deposition of film of manganese and diarsenide of zinc onto silicon substrate and further heat treatment of it.
EFFECT: possibility for producing perspective product for wide usage due to combining semiconductor and ferromagnetic properties of hetero-structure with Curie temperature significantly exceeding 20°C and due to its compatibility with silicon technique.
3 ex, 2 dwg
FIELD: electronic engineering; materials for miscellaneous semiconductor devices using gallium arsenide epitaxial layers.
SUBSTANCE: intermetallic compounds chosen from group incorporating tin arsenide SnAs, palladium antimonide PdSb, manganese polyantimonide Mn2Sb, nickel stannate Ni3Sn2, nickel aluminate Ni2Al3, nickel germanate Ni2Ge, and cobalt germanate Co2Ge are used as materials of substrates for growing gallium arsenide epitaxial layers.
EFFECT: enhanced structural heterogeneity of gallium arsenide layers being grown.
SUBSTANCE: invention relates to vacuum technology and the technology of making carbon nanotubes, such as carbon nanotubes at ends of probes, which are used in probe microscopy for precision scanning. The method of making probes with carbon nanotubes is realised by depositing carbon films with nanotubes through magnetron sputtering in a vacuum at direct current of 100-140 mA using a carbon target with a nanotube growth catalyst. Work pieces of the probes are put into a vacuum installation. A carbon film with nanotubes is then sputtered in a residual atmosphere of inert gas.
EFFECT: invention allows for obtaining probes with carbon nanotubes, lying perpendicular the surface of the probe, in required amounts without using explosive substances and complex devices.
SUBSTANCE: invention can be used in manufacturing organic light-emitting diodes, liquid-crystal displays, plasma display panel, thin-film solar cell and other electronic and semi-conductor devices. Claimed is element, including target of ionic dispersion, where said target includes processed MoO2 plate of high purity. Method of such plate manufacturing includes isostatic pressing of component consisting of more than 99% of stoichiometric MoO2 powder into workpiece, sintering of said workpiece under conditions of supporting more than 99% of MoO2 stoichiometry and formation of plate which includes more than 99% of stoichiometric MoO2. In other version of said plate manufacturing component, consisting of powder, which contains more than 99% of stoichiometric MoO2, is processed under conditions of hot pressing with formation of plate. Method of thin film manufacturing includes stages of sputtering of plate, which contains more than 99% of stoichiometric MoO2, removal of MoO2 molecules from plate and application of MoO2 molecules on substrate. Also claimed is MoO2 powder and method of said plate sputtering with application of magnetron sputtering, pulse laser sputtering, ionic-beam sputtering, triode sputtering and their combination.
EFFECT: invention allows to increase work of output of electron of ionic sputtering target material in organic light-emitting diodes.
16 cl, 5 ex
SUBSTANCE: in method for growing of silicon-germanium heterostructures by method of molecular-beam epitaxy of specified structures due to silicon and germanium evaporation from separate crucible molecular sources on the basis of electronic-beam evaporators, silicon evaporation is done in automatic crucible mode from silicon melt in solid silicon shell, and germanium is evaporated from germanium melt in silicon insert, which represents a previously spent hollow residue, produced as a result of silicon evaporation in automatic crucible mode, and arranged in crucible cavity of cooled case of crucible unit of electron-beam evaporator used to develop molecular flow of germanium. At the same time process of epitaxy is controlled with account of germanium deposition speed selection, determined from given dependence.
EFFECT: increased stability and expansion of assortment of generated high-quality silicon-germanium heterostructures as a result of improved control of molecular-beam epitaxy of heterostructures due to accurate control of silicon and germanium deposition mode in the optimal range of speed values, reduction of concentration of uncontrolled admixtures in heterostructures produced by proposed method, and reduction of resource expenditures for preparation of process equipment.
2 cl, 3 dwg
SUBSTANCE: invention relates to the field of nanotechnologies and may be used to form nanostructures from evaporated microdrop by exposure to acoustic fields. Complex for formation of nanostructures comprises a nanostructures shaper, an optical microscope, a data display facility and information processing and complex control facility. The nanostructures shaper comprises a foundation and a source of shaping action, at the same time the foundation is formed as piezoelectric with the possibility to apply initial substrate on its surface, and the source of nanostructure-shaping action is represented by surface acoustic waves (SAW), besides, to develop a SAW line, a pair of interdigital transducers (IT) is located on the piezoelectric foundation with the possibility to excite the acoustic field between them, and the shaper is installed in the object area of the optical microscope, at the same time the axis of the microscope sighting is aligned relative to the foundation at the angle φ, besides, the complex also includes a generator of high-frequency oscillations and a wideband amplifier connected to it and to IT.
EFFECT: provision of universality as regards a class of objects exposed to nanostructuring.
12 cl, 1 dwg, 1 tbl
SUBSTANCE: invention relates to the field of nanotechnologies and may be used to make ordered nanostructures, used in micro- and nanoelectronics, optics, nanophotonics, biology and medicine. The proposed method may be used to manufacture single-layer and multilayer nanostructures, also the ones containing layers of different composition, and also two-dimensional, three-dimensional ordered structures of various materials. According to the method, the substrate and the initial substrate, containing nanoparticles, are arranged to form a space between them. The substrate is sprayed in the specified space in the form of a cloud of drops, every of which contains at least one nanoparticles. Creation of a substrate in the form of a sprayed cloud of drops is done by means of ultrasound exposure, when the source of ultrasound effect is located relative to the substrate with the possibility to arrange a sprayed cloud of drops in the specified space. Control of motion in the specified space and drops deposition onto the substrate is carried out through their exposure to external electric and/or magnetic fields.
EFFECT: wider class of materials, which could be used to form ordered nanostructures, higher accuracy of nanoobjects reproduction, stability of nanostructures formation process in one technological space.
FIELD: power engineering.
SUBSTANCE: films and layers of tellurium with single-crystal structure are produced on crystal faces by means of tellurium conversion into a monatomic steam and growth of single-structure specimens from it, at the same time the process of deposition is carried out in atmosphere of hydrogen at PH2=1.8 atm, temperature of initial tellurium T2=600°C and temperature of substrate zone T1=400°C.
EFFECT: production of films and layers of tellurium of single-crystal structure at orienting substrates.
SUBSTANCE: vacuum sputtering plant comprises a resistive source of an evaporated material connected to a power supply unit, and facing with the first side towards the substrate, on which a semiconductor structure is generated, and with the second one - to a receiver of charged particles connected to a negative terminal of a source of accelerating voltage, to a positive terminal of which voltage is connected. The receiver of charged particles may be arranged in the form of a plate of a refractory metal.
EFFECT: higher stabilisation of an evaporation speed, reproducibility of sputtered material layers by thickness and higher quality of manufactured structures.
4 cl, 1 dwg