scholarly journals Влияние асимметрии расположения металлических масок на согласование нижнего электрода с высокочастотным генератором смещения при реактивно-ионном травлении массивных подложек

2021 ◽  
Vol 55 (12) ◽  
pp. 1255
Author(s):  
С.Д. Полетаев ◽  
А.И. Любимов
Keyword(s):  
Charge Density ◽  
Current Density ◽  
High Frequency ◽  
Sharp Increase ◽  
Reactive Power ◽  
Lower Electrode ◽  
Near Surface ◽  
Electric Charge Density ◽  
Chemically Active Plasma ◽  
Theoretical Results

The effect of the degree of asymmetry in the arrangement of metal masks on the matching of the lower electrode with a high-frequency displacement generator during selective reactive-ion etching of massive substrates in plasma-forming gas mixtures based on freon-14 is studied theoretically and experimentally. Theoretically, the absence of the influence of the asymmetry of the mask location on the specific reactive power is shown. It is shown that at the edge of the substrate, especially with a mask, there is a sharp increase in the RF current density, which proves mainly the surface (end) nature of its flow. The influence of the mask location on the behavior of the electric charge density, which correlates with the distribution of the RF current density in the near-surface layer of the substrate, is established. No redistribution of the charge density of the chemically active plasma particles at the edge of the mask was detected. In accordance with the theoretical results obtained, it is experimentally shown that metal masks with a side length ratio of 36/0 mm reduce the power reflection coefficient within 5%.

scholarly journals Влияние металлических масок на согласование нижнего электрода с высокочастотным генератором смещения при реактивно-ионном травлении массивных подложек

2021 ◽  
Vol 47 (11) ◽  
pp. 44
Author(s):  
С.Д. Полетаев ◽  
А.И. Любимов
Keyword(s):  
Reflection Coefficient ◽  
High Frequency ◽  
Reactive Power ◽  
Reactive Ion Etching ◽  
Substrate Holder ◽  
Lower Electrode ◽  
Ion Etching ◽  
Power Reflection Coefficient ◽  
Power Component

The effect of metal masks on the matching of the lower electrode with a high-frequency bias generator during selective reactive-ion etching through the mask of massive substrates in freon-14 has been studied theoretically and experimentally. It is shown that masks with a substrate coating above 30% lead to an increase in the reactive power component at distances from the center close to the substrate radius. The absence of influence on the specific reactive power of the thickness and material of the masks is established. It is experimentally shown that masks with any practically significant coating coefficient of the substrate, connected to the lower electrode through the substrate holder, improve the matching, reducing the power reflection coefficient.

High-frequency, "quantum" and electromechanical effects in quasi-one-dimensional charge density wave conductors

2013 ◽  
Vol 183 (1) ◽  
pp. 33-54 ◽  
Author(s):  
Vadim Ya. Pokrovskii ◽  
Sergey G. Zybtsev ◽  
Maksim V. Nikitin ◽  
Irina G. Gorlova ◽  
Venera F. Nasretdinova ◽  
...  
Keyword(s):  
Charge Density ◽  
High Frequency ◽  
Charge Density Wave ◽  
Density Wave ◽  
One Dimensional ◽  
Electromechanical Effects

ИССЛЕДОВАНИЯ АКУСТИЧЕСКИХ ХАРАКТЕРИСТИК ВЕРХНЕГО СЛОЯ МОРЯ МЕТОДОМ МНОГОЧАСТОТНОГО АКУСТИЧЕСКОГО ЗОНДИРОВАНИЯ

2020 ◽  
Author(s):  
V.A. Bulanov ◽  
I.V. Korskov ◽  
A.V. Storozhenko ◽  
S.N. Sosedko
Keyword(s):  
High Frequency ◽  
Wave Motion ◽  
High Spatial Resolution ◽  
Wind Waves ◽  
Acoustic Parameter ◽  
Sea Surface ◽  
Near Surface ◽  
Acoustical Properties ◽  
Acoustic Spectroscopy ◽  
Sea Bottom

Описано применение акустического зондирования для исследования акустических характеристик верхнего слоя моря с использованием широкополосных остронаправленных инвертированных излучателей,устанавливаемых на дно. В основу метода положен принцип регистрации обратного рассеяния и отраженияот поверхности моря акустических импульсов с различной частотой, позволяющий одновременно измерятьрассеяние и поглощение звука и нелинейный акустический параметр морской воды. Многочастотное зондирование позволяет реализовать акустическую спектроскопию пузырьков в приповерхностных слоях моря,проводить оценку газосодержания и получать данные о спектре поверхностного волнения при различных состояниях моря вплоть до штормовых. Применение остронаправленных высокочастотных пучков ультразвукапозволяет разделить информацию о планктоне и пузырьках и определить с высоким пространственным разрешением структуру пузырьковых облаков, образующихся при обрушении ветровых волн, и структуру планктонных сообществ. Участие планктона в волновом движении в толще морской воды позволяет определитьпараметры внутренних волн спектр и распределение по амплитудам в различное время.This paper represents the application of acoustic probingfor the investigation of acoustical properties of the upperlayer of the sea using broadband narrow-beam invertedtransducers that are mounted on the sea bottom. Thismethod is based on the principle of the recording of thebackscattering and reflections of acoustic pulses of differentfrequencies from the sea surface. That simultaneouslyallows measuring scattering and absorption of the soundand non-linear acoustic parameter of seawater. Multifrequencyprobing allows performing acoustic spectroscopy ofbubbles in the near-surface layer of the sea, estimating gascontent, and obtaining data on the spectrum of the surfacewaves in various states of the sea up to a storm. Utilizationof the high-frequency narrow ultrasound beams allows us toseparate the information about plankton and bubbles and todetermine the structure of bubble clouds, created during thebreaking of wind waves, along with the structure of planktoncommunities with high spatial resolution. The participationof plankton in the wave motion in the seawater columnallows determining parameters of internal waves, such asspectrum and distribution of amplitudes at different times.

scholarly journals A Method for Processing Acoustic Doppler Current Profiler Velocity Data from Towed, Undulating Vehicles

2008 ◽  
Vol 25 (9) ◽  
pp. 1710-1716 ◽  
Author(s):  
Jiayi Pan ◽  
David A. Jay
Keyword(s):  
Surface Waters ◽  
High Frequency ◽  
Acoustic Doppler Current Profiler ◽  
Small Time ◽  
Ocean Current ◽  
Near Surface ◽  
Vertical Range ◽  
External Reference ◽  
Current Profiler ◽  
Adcp Measurements

Abstract The utility of the acoustic Doppler current profiler (ADCP) for sampling small time and space scales of coastal environments can be enhanced by mounting a high-frequency (1200 kHz) ADCP on an oscillating towed body. This approach requires both an external reference to convert the measured shears to velocities in the earth coordinates and a method to determine the towed body velocities. During the River Influence on the Shelf Ecosystems (RISE) project cruise, a high-frequency (1200 kHz) and narrowbeam ADCP with mode 12 sampling was mounted on a TRIAXUS oscillating towfish, which steers a 3D path behind the ship. This deployment approach extended the vertical range of the ADCP and allowed it to sample near-surface waters outside the ship’s wake. The measurements from a ship-mounted 1200-kHz narrowbeam ADCP are used as references for TRIAXUS ADCP data, and a method of overlapping bins is employed to recover the entire vertical range of the TRIAXUS ADCP. The TRIAXUS vehicle horizontal velocities are obtained by removing the derived ocean current velocity from the TRIAXUS ADCP measurements. The results show that the method is practical.

Effect of operating conditions on current density distribution and high frequency resistance in a segmented PEM fuel cell

2012 ◽  
Vol 37 (9) ◽  
pp. 7736-7744 ◽  
Author(s):  
Dietmar Gerteisen ◽  
Nada Zamel ◽  
Christian Sadeler ◽  
Florian Geiger ◽  
Victor Ludwig ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Density Distribution ◽  
Current Density ◽  
High Frequency ◽  
Current Density Distribution ◽  
Pem Fuel Cell ◽  
Operating Conditions

Influence of ion treatment modes on the physical and mechanical properties of zirconia ceramics

2020 ◽  
Vol 10 ◽  
pp. 5-18
Author(s):  
S. А. Ghyngаzоv ◽  
◽  
V. А. Коstеnко ◽  
A. K. Khassenov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Current Density ◽  
Ion Beam ◽  
Physical And Mechanical Properties ◽  
Oxygen Stoichiometry ◽  
Continuous Mode ◽  
Zirconia Ceramics ◽  
Surface Layers ◽  
Near Surface ◽  
Ion Treatment

The article considers the influence of the treatment modes by N2+ and Ar+ ions beams on the physical and mechanical properties of zirconia ceramics. Surface modification of zirconia ceramics was performed using two modes of ion treatment — pulsed and continuous. The pulse mode of treatment by N2+ ions was realized at an accelerating voltage of 250 – 300 kV, current density j = 150 – 200 A/cm2, and energy density W = (3.5 and 5) ± 5 % J/cm2. The continuous mode of treatment by Ar+ ions was realized at an accelerating voltage of 30 kV and an ion current density of 300 and 500 μA/cm2. The fluence of the Ar+ ion beam varied from 1016 to 1018 cm–2. It is established that the pulsed mode of ion treatment leads to the melting and recrystallization of the surface of ceramics. It is shown that this treatment leads to a violation of the oxygen stoichiometry in ceramics and, as a result, there is an appearance of electrical conductivity in the near-surface layers, the layers of zirconia ceramics become conductive. It was established that the continuous mode of ion treatment does not lead to the melting and recrystallization of the ceramics surface, but is accompanied by its slight etching. It is shown that under the action of continuous ion treatment, microhardness increases (by 14 %). Hardening of the surface layers of ceramics is observed at a depth that exceeds the average projected range of Ar+ ion by 103 times.

Rainfall-Induced Variation of Seismic Waves Velocity in Soil and Implications for Soil Response: What the ARGONET (Cephalonia, Greece) Vertical Array Data Reveal

2020 ◽  
Vol 110 (2) ◽  
pp. 441-451
Author(s):  
Zafeiria Roumelioti ◽  
Fabrice Hollender ◽  
Philippe Guéguen
Keyword(s):  
Ground Motion ◽  
High Frequency ◽  
Surface Velocity ◽  
Depth Interval ◽  
Seasonal Effect ◽  
Surface Wave Dispersion ◽  
Near Surface ◽  
Soil Response ◽  
Earthquake Records ◽  
Shallow Sediments

ABSTRACT We apply interferometry by deconvolution to compute the shear-wave velocity in shallow sediments (0–83.4 m) based on earthquake records from a vertical accelerometric array (ARGOstoli Network [ARGONET]) on Cephalonia Island, Greece. Analysis of the time variation of measured values reveals a cyclical pattern, which correlates negatively to rainfall and a soil moisture proxy. The pattern includes a sharp reduction in velocity at the beginning of rainy seasons and a gradual rise toward dry periods, the overall variation being around 20%–25% within the shallowest depth interval examined (0–5.6 m) and estimated to reach 40% within the top 2 m. The variation itself and its amplitude are verified by surface-wave dispersion analysis, using ambient vibration data. Synthetic standard spectral ratios suggest that this seasonal effect leaves an imprint on soil response, causing differences in the level of high-frequency ground motion between dry and rainy seasons, and this is verified by earthquake records. Furthermore, the near-surface velocity decrease due to soil saturation can be of the same order of magnitude as the nonlinear coseismic variation, masking the physical process of the nonlinear response of the site due to weak-to-strong-motion shaking. Thus, seasonal variations of seismic-wave velocities in shallow sediments may be important for a number of site-effect related topics, such as high-frequency ground-motion variability, soil anisotropy, kappa measurements, nonlinear site response, and so on.

scholarly journals Investigation of AC-Measurements of Epoxy/Ferrite Composites

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 492 ◽  
Author(s):  
Moustafa A. Darwish ◽  
Alex V. Trukhanov ◽  
Oleg S. Senatov ◽  
Alexander T. Morchenko ◽  
Samia A. Saafan ◽  
...  
Keyword(s):  
Experimental Data ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
High Frequency ◽  
Precipitation Method ◽  
Semiconductor Behavior ◽  
Ferrite Composites ◽  
Co Precipitation ◽  
Theoretical Results ◽  
Composite Samples

A pure ferrite and epoxy samples as well as the epoxy/ferrite composites with different 20 wt.%, 30 wt.%, 40 wt.%, and 50 wt.% weight ferrite contents have been prepared by the chemical co-precipitation method. AC-conductivity and dielectric properties such as the dielectric constant and dielectric loss of the prepared samples have been studied. The obtained results showed that the samples had a semiconductor behavior. The dielectric constant of the composites has been calculated theoretically using several models. For the composite sample that contains 20 wt.% of ferrites, these models give satisfactory compliance, while for the composite samples with a higher percentage of nanofillers, more than 30 wt.% theoretical results do not coincide with experimental data. The investigated polymer has very low conductivity, so this type of polymer can be useful for high-frequency applications, which can reduce the losses caused by eddy current. Thus, the prepared samples are promising materials for practical use as elements of microwave devices.

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