157 research outputs found
Mechanical impulse enhancement in a microsystem based on nanoporous silicon combustion
Nanostructured porous silicon impregnated by solid state oxidizer has been studied in order to provide the mechanical impulse for jet-propulsion microsystems. The system with jet-propulsion motion on a silicon chip has been tested for impulse measurements. The silicon chip has been fastened on a carrying platform through an elastic spacer. The elastic spacer promotes the combustion and prevents from explosion of porous silicon fast oxidation. It is shown that such a microsystem gains the impulse up to 200-220 mN•s
Mössbauer spectroscopy investigation of magnetic nanoparticles incorporated into carbon nanotubes obtained by the injection CVD method
This paper is devoted to the investigation of phase composition of the
magnetic filler located inside multi-wall carbon nanotubes (CNTs) using Mössbauer
spectroscopy, scanning electron microscopy (SEM) and transmission electron
microscopy (TEM). CNTs were obtained by the injection CVD method using ferrocenexylene
solution under various conditions (i.e., the ferrocene concentration cx (1%, 5%,
and 10%), slow or fast cooling down rates of the synthesis reactor, temperature in the
reaction zone during synthesis), which can influence the magnetic properties of CNTs
owing to different contribution of Fe-containing phases. SEM and TEM methods were
applied to investigate morphology and structure of the synthesized material. It was
shown that Fe₃C phase formation is favorable at high content of the catalyst in the
feeding solution (10%), relatively low temperatures (775 ºC) during CNTs synthesis, as
well as long duration of the CNTs growth process (5 min). The cooling rate of the reactor
after CNTs synthesis was not crucial to iron phase contribution in our experiments
Composite nanostructure of vertically aligned carbon nanotube array and planar graphite layer obtained by the injection CVD method
The carbon nanostructure composed of an array of vertically aligned carbon
nanotubes (CNTs) and a planar graphite layer (PGL) located at the top of the array has
been obtained by the injection chemical vapor deposition method, realized using high
temperature catalytic pyrolysis of xylene-ferrocene mixture. The carbon nature of the
planar layer was identified using Auger electron spectroscopy. Scanning electron
microscopy analysis enabled to ascertain peculiarities of CNT-PGL nanostructure
morphology, in particular, the internal layer-built structure of PGL and its links with the
underlying CNT array. The mechanism of CNT-PGL nanostructure formation was
considered
Local electrochemical deposition of Ni into vertical vias in Si/SiO2 substrate
Ni electrochemical deposition into a matrix of various
diameters (500–2000 nm) vertical vias in Si/SiO2 substrates with a
barrier layer at the vias’ bottom has been investigated. Morphological
study of Ni deposits in the vias showed they are deposited directly on
the surface of the barrier layer. Repeatability and stability in
combination with a homogeneous structure and 70% filling degree of
vias determine the prospects of the Si/SiO2/Ni system as a basic element
for the creation of three-dimensional micro-, nanostructures, and 3D
assembly of IC crystals
Quantum drift-diffusion models for dual-gate field-effect transistors based on mono- and bilayer graphene
At present, a great deal of interest is observed in devices based
on two-dimentional (2D) materials, especially graphene, in the field of
micro- and nanoelectronics. Graphene has robust hoheycomb lattice
structure and unique properties such as ambipolarity, high carrier
mobility, high conductivity. Nevertheless the properties of mono- and
bilayer graphene are different
Simulation of various nanoelectronic devices based on 2D materials
The development of field-effect transistors (FETs), resonant-
tunneling diodes (RTDs), vertical heterostructures and other device
structures on the basis of 2D materials is one of the important tasks for
producing a new element base for micro and nanoelectronics
Plasma assisted-MBE of GaN and AlN on graphene buffer layers
The possibility of using chemical vapor deposition (CVD) graphene as a 2D buffer layer for epitaxial growth of III-nitrides by plasma assisted-MBE on amorphous substrates (SiO2 prepared by thermal oxidation of Si wafer) was investigated. The comparative study of graphene-coated parts of the wafers and the parts without graphene was carried out by scanning electron microscopy and X-ray diffractometry. It was shown that epitaxial GaN and AlN films with close to 2D surface morphology can be obtained by plasma assisted-MBE on amorphous SiO2 substrates with a multilayer graphene buffer using the HT AlN nucleation layer
Study of the Thermal Stability of Copper Contact Junctions in Si/SiO2 Substrates
The results of a comprehensive study of the structural-
morphological and thermodynamic characteristics of the electrochemical
precipitation of Cu in transition holes with a barrier layer of TiN in
Si/SiO2 substrates by scanning electron microscopy (SEM) and
differential thermal analysis (DTA) are presented. The temperature
range that determines the heat resistance of copper (up to 750°C) and the
temperature range (up to 886°C) that determines the thermal stability of
the composite as a whole, as well as the ability to maintain the chemical
composition and ordered structure at elevated temperatures, are found
3D Silicon Photonic Structures Based on Avalanche LED with Interconnections through Optical Interposer
Design and manufacturing technology of 3-D silicon photonic structures with optical interconnections through microchannel vias interposers were developed. Silicon chips placed over each other were separated by the silicon microchannel vias interposer served as a light waveguide. Light emitting diodes and photodiodes were formed at the inner surfaces of silicon chips from nanostructured silicon clusters embedded into alumina matrix. The developed structure is characterized by the current conversion efficiency of 0.1 % and can operate in the GHz frequency range
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