Stanislav Moshkalev - Academia.edu (original) (raw)

Papers by Stanislav Moshkalev

Physics, Chemistry and Applications of Nanostructures, 2013

2014 IEEE 2nd International Conference on Emerging Electronics (ICEE), 2014

Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques, 2013

The thermal resistance of the contact between a metal and carbon nanotubes (CNTs) and between CNT... more The thermal resistance of the contact between a metal and carbon nanotubes (CNTs) and between CNT layers is estimated by the local heating of CNT arrays (films) of different thicknesses using a focused laser beam and measuring their local temperature via Raman spectroscopy. It is demonstrated that thermal contacts between nanotubes, and also between CNTs and an electrode, can be formed by means of laser annealing.

Bulletin of the Russian Academy of Sciences: Physics, 2014

The possibility of fabricating high quality thin (10-100 nm), flexible, semitransparent films of ... more The possibility of fabricating high quality thin (10-100 nm), flexible, semitransparent films of multilayer graphene and graphite nanoplates (ultrathin graphite) using a modified Langmuir-Blodgett method is demonstrated. The high quality of the resulting samples is confirmed via Raman spectroscopy and high resolution scanning electron microscopy. Measurements of the films' surface resistance show values of 100 Ω/sq or less.

28th Symposium on Microelectronics Technology and Devices (SBMicro 2013), 2013

ABSTRACT In this work we used a new approach for electrical contact improvement between multi-wal... more ABSTRACT In this work we used a new approach for electrical contact improvement between multi-wall carbon nanotubes and metallic electrodes by localized laser heating. The nanotubes were suspended, using the dielectrophoresis technique, over a gap of 1μm width and 5μm depth connecting the ends of the patterned electrodes. Subsequently, the as deposited nanotubes were directly heated, in ambient atmosphere, by a laser having a wavelength of 473nm. The Raman signal of the nanotubes, through its G band displacement, was used to determine the process temperature and this parameter was controlled by calibrating the incident power density. The changes in the nanotubes morphology were evaluated using scanning electron microscopy, Raman spectroscopy and electrical measurements. After calibration, this method was employed for improving the electrical contact between suspended multi-wall carbon nanotubes and different electrodes (W, Ti and Au). The reduction in the electrical resistance was between 80 - 99%, 80 - 95% and 10 - 90% for W, Ti and Au electrodes, respectively, resulting in contact resistivity as low as ~1 kΩμm2.

Journal of Nanoelectronics and Optoelectronics, 2014

Authors: Silveira, J. V.; Savu, R.; Canesqui, M. A.; Alves, O. L.; Filho, J. Mendes; Swart, J. W.... more Authors: Silveira, J. V.; Savu, R.; Canesqui, M. A.; Alves, O. L.; Filho, J. Mendes; Swart, J. W.; Filho, A. G. Souza; Moshkalev, S. A.

Microelectronic Engineering, 2014

A new approach for electrical and thermal improvement of contacts between carbon nanostructures (... more A new approach for electrical and thermal improvement of contacts between carbon nanostructures (multi-wall carbon nanotubes -MWCNTs and multi-layer graphene -MLG) and metal electrodes by localized laser heating is presented. The nanostructures were deposited over electrodes using the dielectrophoresis (DEP) technique. A focused laser beam was used for direct heating the samples in ambient atmosphere. The Raman spectroscopy was used to determine the process temperature by observations of the graphitic G-line downshift. In the laser annealing experiments, the G-line position was found first to downshift linearly with laser power indicating gradual heating of the sample proportional to the absorbed power. However, with increasing power the shift was found to saturate at levels that depend on the metal and the contact area. This saturation was attributed to gradual increase of the contact area and improvement of the thermal contacts between the nanostructures and metal electrode that can occur during sample heating. The maximum sample temperature in the beginning of the annealing process was always higher for MLG samples, due to smaller area of contact established between rigid multi-layer graphene and initially rough metal surface. The final result is the increased heat losses to the electrodes and, subsequently, the reduction of the samples temperature.

Applied Surface Science, 2008

A novel approach to produce electron-transparent multi-layer membranes over TEM grids for transmi... more A novel approach to produce electron-transparent multi-layer membranes over TEM grids for transmission electron microscopy analysis is presented. The membranes have been used to grow and analyze carbon nanostructured materials in a thermal-chemical vapor deposition process using Ni and Cu as catalysts and silicon oxide thin films as support layers, at temperatures as high as 900 8C. It is important that conditions of the synthesis using the electron-transparent multi-layer membrane system are similar to those for a conventional chemical vapor deposition process, where oxidized silicon wafers are employed. In particular, the thickness of the silicon oxide and the catalyst layers are the same, and similar carbon tubular structures were grown using both substrates. The use of membranes was crucial especially for the study of the nucleation mechanism for carbon nanotubes. These electron-transparent multi-layer membranes are relatively easy to obtain and they can be used for transmission electron microscopy studies of high-temperature synthesis of different nanostructured materials. #

Chemical Physics Letters, 2009

Multi-wall carbon nanotubes decorated by Ti nanoparticles were used for gas (N 2 , Ar, O 2 ) sens... more Multi-wall carbon nanotubes decorated by Ti nanoparticles were used for gas (N 2 , Ar, O 2 ) sensing at low temperatures. Chemiresistor sensor configurations with supported and suspended nanotubes were tested. Two gas sensing mechanisms (chemical and electrothermal) were demonstrated, with their relative contributions strongly depending on the sensor configuration. For suspended nanotubes, heating by Joule effect results in strong enhancement of chemical sensitivity to oxygen.

Sensor Letters, 2010

Mechanisms of gas sensing in sensors based on multi-wall carbon nanotubes decorated by Ti nanopar... more Mechanisms of gas sensing in sensors based on multi-wall carbon nanotubes decorated by Ti nanoparticles have been studied. Tests were performed with N 2 , Ar and O 2 at low temperatures. Chemi-resistor sensor configurations with supported and suspended nanotubes were tested. Contributions from two gas sensing mechanisms (chemical and electrothermal) were shown to depend strongly on a sensor configuration. For suspended nanotubes, their heating by Joule effect results in much stronger and faster sensor response to oxygen. Oxygen detection with high sensitivity in this case was achieved at room temperature.

2010 10th IEEE International Conference on Solid-State and Integrated Circuit Technology, 2010

... carbon nanotubes Jacobus W. Swart*1 and Stanislav A. Moshkalev2 1Center for Information Techn... more ... carbon nanotubes Jacobus W. Swart*1 and Stanislav A. Moshkalev2 1Center for Information Technology Renato Archer, Campinas, SP, 13069-901, Brazil 2Center for Semiconductor Components, UNICAMP, Campinas, SP, 13083-870, Brazil * Email: jacobus.swart@cti.gov.br ...

2008 9th International Conference on Solid-State and Integrated-Circuit Technology, 2008

Beilstein Journal of Nanotechnology, 2015

In this paper we study in detail the post-growth annealing of a copper-containing material deposi... more In this paper we study in detail the post-growth annealing of a copper-containing material deposited with focused electron beam induced deposition (FEBID). The organometallic precursor Cu(II)(hfac)2 was used for deposition and the results were compared to that of compared to earlier experiments with (hfac)Cu(I)(VTMS) and (hfac)Cu(I)(DMB). Transmission electron microscopy revealed the deposition of amorphous material from Cu(II)(hfac)2. In contrast, as-deposited material from (hfac)Cu(I)(VTMS) and (hfac)Cu(I)(DMB) was nano-composite with Cu nanocrystals dispersed in a carbonaceous matrix. After annealing at around 150-200 °C all deposits showed the formation of pure Cu nanocrystals at the outer surface of the initial deposit due to the migration of Cu atoms from the carbonaceous matrix containing the elements carbon, oxygen, and fluorine. Post-irradiation of deposits with 200 keV electrons in a transmission electron microscope favored the formation of Cu nanocrystals within the carbonaceous matrix of freestanding rods and suppressed the formation on their surface. Electrical four-point measurements on FEBID lines from Cu(hfac)2 showed five orders of magnitude improvement in conductivity when being annealed conventionally and by laser-induced heating in the scanning electron microscope chamber.

ABSTRACT Inductively Coupled Plasma (ICP) discharges currently are considered as the main tool fo... more ABSTRACT Inductively Coupled Plasma (ICP) discharges currently are considered as the main tool for plasma processing in the microelectronics industry. A comprehensive understanding of ICP's finctionality and behavior is fundamental for the evolution of this technology. This understanding requires its modeling as an electrical lumped circuit. Existing electrical models cannot explain all the characteristics of an ICP discharge, especially the E-to-H mode transition. In this work, preliminary results on the modeling of ICP plasma and the possibility to incorporate the plasma kinetics, particulary the effect of metastables on the transition, is discussed.