High Mobility Nitrides

2001 ◽  
Vol 693 ◽  
Author(s):  
K. Scott ◽  
A. Butcher ◽  
Marie Wintrebert-Fouquet ◽  
Patrick P.–T. Chen ◽  
Trevor L. Tansley ◽  
...  
Keyword(s):  
Indium Nitride ◽  
High Mobility ◽  
Lag Time ◽  
Growth Conditions ◽  
Growth Time ◽  
Ion Sputtering ◽  
System A ◽  
Polycrystalline Thin Films ◽  
Reactive Ion Sputtering ◽  
Stable Material

AbstractThe highest mobility nitrides ever grown were indium nitride polycrystalline thin films. The original reactive ion sputtering unit used to produce those films is still in existence and has been substantially upgraded. In this paper we describe some of the parameters that are important for high purity indium nitride growth, while providing the most recent results for films grown with the upgraded system. A long lag time (greater than 100 hours of growth time) has been observed before obtaining stable material properties for a given set of growth conditions.

Wear improvement and local structure in nickel-titanium coatings produced by reactive ion sputtering

1996 ◽  
Vol 283 (1-2) ◽  
pp. 67-74 ◽  
Author(s):  
T Girardeau ◽  
K Bouslykhane ◽  
J Mimault ◽  
J.P Villain ◽  
P Chartier
Keyword(s):  
Local Structure ◽  
Nickel Titanium ◽  
Ion Sputtering ◽  
Titanium Coatings ◽  
Reactive Ion Sputtering

scholarly journals Properties of Al2O3 thin films deposited on 4H-SiC by reactive ion sputtering

2019 ◽  
Vol 93 ◽  
pp. 290-294 ◽  
Author(s):  
P. Fiorenza ◽  
M. Vivona ◽  
S. Di Franco ◽  
E. Smecca ◽  
S. Sanzaro ◽  
...  
Keyword(s):  
Thin Films ◽  
Ion Sputtering ◽  
Reactive Ion Sputtering

The dynamics of reactive ion sputtering of SnSb and InSn alloys in an ArO2 atmosphere

1981 ◽  
Vol 76 (3) ◽  
pp. 283-287 ◽  
Author(s):  
E. Leja ◽  
A. Kołodziej ◽  
T. Pisarkiewicz ◽  
T. Stapiński
Keyword(s):  
Ion Sputtering ◽  
Reactive Ion Sputtering

Coherent island formation of Cu2O films grown by chemical vapor deposition on MgO(110)

2001 ◽  
Vol 16 (8) ◽  
pp. 2408-2414 ◽  
Author(s):  
P. R. Markworth ◽  
X. Liu ◽  
J. Y. Dai ◽  
W. Fan ◽  
T. J. Marks ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Strain Relaxation ◽  
Three Dimensional ◽  
High Mobility ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Growth Conditions ◽  
Island Formation ◽  
Transmission Electron

Cuprous oxide (Cu2O) films have been grown on single-crystal MgO(110) substrates by a chemical vapor deposition process in the temperature range 690–790 °C. X-ray diffraction measurements show that phase-pure, highly oriented Cu2O films form at these temperatures. The Cu2O films are observed to grow by an island-formation mechanism on this substrate. Films grown at 690 °C uniformly coat the substrate except for micropores between grains. However, at a growth temperature of 790 °C, an isolated, three-dimensional island morphology develops. Using a transmission electron microscopy and atomic force microscope, both dome- and hut-shaped islands are observed and are shown to be coherent and epitaxial. The isolated, coherent islands form under high mobility growth conditions where geometric strain relaxation occurs before misfit dislocation can be introduced. This rare observation for oxides is attributed to the relatively weak bonding of Cu2O, which also has a relatively low melting temperature.

scholarly journals A Computational Model of Bidirectional Axonal Growth in Micro-Tissue Engineered Neuronal Networks (micro-TENNs)

2018 ◽  
Author(s):  
Toma Marinov ◽  
Liang Yuchi ◽  
Dayo O. Adewole ◽  
D. Kacy Cullen ◽  
Reuben H. Kraft
Keyword(s):  
White Matter ◽  
Computational Model ◽  
Large Scale ◽  
Three Dimensional ◽  
Growth Conditions ◽  
Growth Time ◽  
Directional Growth ◽  
System Reconstruction ◽  
Realistic Neuron

AbstractMicro-Tissue Engineered Neural Networks (Micro-TENNs) are living three-dimensional constructs designed to replicate the neuroanatomy of white matter pathways in the brain, and are being developed as implantable microtissue for axon tract reconstruction or as anatomically-relevant in vitro experimental platforms. Micro-TENNs are composed of discrete neuronal aggregates connected by bundles of long-projecting axonal tracts within miniature tubular hydrogels. In order to help design and optimize micro-TENN performance, we have created a new computational model including geometric and functional properties. The model is built upon the three-dimensional diffusion equation and incorporates large-scale uni- and bi-directional growth that simulates realistic neuron morphologies. The model captures unique features of 3D axonal tract development that are not apparent in planar outgrowth, and may be insightful for how white matter pathways form during brain development. The processes of axonal outgrowth, branching, turning and aggregation/bundling from each neuron are described through functions built on concentration equations and growth time distributed across the growth segments. Once developed we conducted multiple parametric studies to explore the applicability of the method and conducted preliminary validation via comparisons to experimentally grown micro-TENNs for a range of growth conditions. Using this framework, this model can be applied to study micro-TENN growth processes and functional characteristics using spiking network or compartmental network modeling. This model may be applied to improve our understanding of axonal tract development and functionality, as well as to optimize the fabrication of implantable tissue engineered brain pathways for nervous system reconstruction and/or modulation.

scholarly journals Спонтанное формирование кластеров In в эпитаксиальных слоях InN, выращенных методом молекулярно-пучковой эпитаксии

2018 ◽  
Vol 44 (4) ◽  
pp. 42
Author(s):  
Т.А. Комиссарова ◽  
В.Н. Жмерик ◽  
С.В. Иванов
Keyword(s):  
Molecular Beam ◽  
Indium Nitride ◽  
Growth Conditions ◽  
Nitrogen Plasma ◽  
Nitrogen Flow ◽  
Model Approximation ◽  
Mbe Growth ◽  
Flow Rates ◽  
Sapphire Substrates ◽  
The Magnetic Field

AbstractWe have studied the influence of growth conditions on the number of metallic indium clusters formed spontaneously in indium nitride (InN) layers grown by nitrogen plasma-assisted molecular-beam epitaxy (PAMBE). InN epilayers of N-and In-polarity were grown on c-sapphire substrates and GaN and AlN templates, respectively. N-polar layers were obtained in the standard PAMBE regime, while In-polar layers were grown using a three-stage regime including the stages of epitaxy with enhanced atomic migration and interruption of growth under nitrogen flow. A series of samples were prepared at various growth temperatures and relative In/N flow rates. Measurement of the magnetic-field dependences of the Hall-effect coefficient and its model approximation were used to determine the percentage content of In clusters in various InN layers and the minimum amount of such inclusions that can be achieved by varying the conditions of MBE growth.

AN APPLICATION OF R-HiPIMS METHOD FOR TiO2-AND TiO2:Cu-BASED MEMRISTORS: CONTROLLING Cu DOPING USING DC PULSE METHOD

2020 ◽  
pp. 2050041
Author(s):  
BANAFSHEH ALIZADEH ARASHLOO ◽  
HASAN EFEOGLU
Keyword(s):  
Thin Films ◽  
Data Storage ◽  
High Power ◽  
Oxygen Deficiency ◽  
High Mobility ◽  
Pulse Method ◽  
Degree Of Crystallinity ◽  
Growth Time ◽  
Transition Elements ◽  
Cu Doping

Nowadays, the High-Power Impulse Magnetron Sputtering (HiPIMS) as an additional technique to plasma-based sputtering, is applied to depositing or coating of thin films. HiPIMS is based on applying high-power and low-duty-cycle unipolar pulses to the magnetron target by a low repetition frequency, which are produced from the high ionization part of sputtered atoms by high discharge power. By applying voltage to substrate and bombarding it in the presence of an inert gas such as Ar, the growth of the film is controlled by the acceleration of the sputtered material across the highly dense plasma. To deposit compound materials, metal targets are sputtered with gases such as CH4, N2, O2, etc. or by Reactive HiPIMS (R-HiPIMS) techniques. The transparent metal oxide (TiO[Formula: see text] film depositions by R-HiPIMS are denser and have flatter surfaces due to a higher degree of crystallinity than other sputtering methods. The applicable potential of TiO2 thin films and similar metal oxides on the ultra-high-density electronic devices due to the presence of oxygen deficiency, leads them to be chosen for memristor devices. As theory predicted, a current-controlled memristor is possible with metal–TiO2–metal structures. But stability and repeatability with high ON/OFF ratios remain as problems. A high ON/OFF ratio due to filament formation is revealed by Cu doping of TiO2 thin films which leads to two state functions to be applicable for the traditional digital electronics. On the other hand, an ideal memristor has a potential for gray scale with no limitation. This approach has a big potential impact on data storage and computation in electronics. A new spotlight for this prediction is recognized by the high mobility of transition elements such as Cu in semiconductors. In this work, a nano-scale memristor based on Cu-doped TiO2 is fabricated from metallic targets (i.e. Ti and Cu) by the R-HiPIMS method. Cu doping is synchronously controlled by using pulsed DC sputtering onto the TiO2 structure. DC pulse duration and its frequency are used for adjusting the Cu doping concentration during the growth time of TiO2. The memristor properties of Cu–Pt–TiO2–p[Formula: see text]Si–Al and Cu–Pt–TiO2:Cu–p[Formula: see text]Si–Al devices are considered. The electrode change effect on the memristive properties and performance of Cu-doped memristor is investigated. The [Formula: see text]–[Formula: see text] characteristic of the Cu-doped memristor with Cu top electrode is recognized to be asymmetric in comparison with Cu-doped TiO2-based memristor with Pt top electrode. The structural, optical and electrical characterizations are carried out and preliminary findings are given in detail.

scholarly journals X-ray investigation of polytype distribution in InAs nanowires during MBE growth

2014 ◽  
Vol 70 (a1) ◽  
pp. C748-C748
Author(s):  
Ullrich Pietsch ◽  
Andreas Biermanns ◽  
Emmanouil Dimakis ◽  
Lutz Geelhaar ◽  
Anton Davydok ◽  
...  
Keyword(s):  
Time Evolution ◽  
Stacking Faults ◽  
Growth Conditions ◽  
Growth Mode ◽  
Ex Situ ◽  
Growth Time ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Liquid Indium

The monolithic integration of III-V semiconductors with Si is the ideal way to combine the superior optoelectronic properties of the compound semiconductors with the mature Si technology. This integration can be realized by growing epitaxially dislocation-free III-V NWs on Si substrates either in the vapor-liquid-solid (VLS) or in the vapor-solid (VS) mode associated with the presence or absence, respectively, of group-III liquid droplets on the NW tips [1]. In this work, we investigate the correlation between the growth mode and the forming polytypes in InAs NWs grown on Si(111). The growth was performed in the molecular beam epitaxy chamber of beamline 11XU at Spring8 [2], while the structural dynamics was probed by in situ x-ray diffraction. Specifically, the time evolution of the formation of wurtzite (WZ) and zincblende (ZB) polytypes was monitored during the NW growth. Despite the As-rich growth conditions, a spontaneous build-up of liquid In on Si was found to be present in the nucleation phase, where the InAs nuclei mainly grow in the WZ phase with low number of stacking faults. Shortly after the nucleation, the liquid In is consumed by the excessive As, and the growth continues in the VS mode with an increasing density of stacking faults forming in the NW crystal. The time evolution of the liquid Indium signal (Fig. (a)) correlates well with the time evolution of wurzite growth rate (Fig (b)). The latter saturates at a time where the liquid indium disappers, i.e. where the VLS changes into the VS mode, whereas the zinc-blende polytypes grow almost continuous in both VLS and VS growth mode. The dynamics of stacking faults density was determined quantitatively by ex-situ X-ray diffraction measuring thestacking fault induced increase of the peak width of wurtzite reflections at InAs nanowire samples of different length ; i.e. growth time [3].

TEM identification of secondary phases in non-stoichiometric polycrystalline CuInSe2 thin films

1990 ◽  
Vol 48 (4) ◽  
pp. 604-605
Author(s):  
J.P. Goral ◽  
M.M. Al-Jassim ◽  
D. Albin ◽  
J.R. Tuttle ◽  
R. Noufi
Keyword(s):  
Thin Films ◽  
Low Cost ◽  
Growth Conditions ◽  
Chalcopyrite Structure ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Cationic Sublattice ◽  
X Ray ◽  
Polycrystalline Thin Films ◽  
Deposition Parameters

Polycrystalline thin films of CuInSe2 and CuGaSe2 are currently being developed as low-cost photovoltaic devices. These films are vacuum-deposited onto molybdenum metallized alumina substrates. The film composition may be varied by manipulation of the deposition parameters. For photovoltaic applications, the desired phase has a stoichiometry close to CuInSe2. This compound is a zincblende variant, the cations and anions occupying separate fcc sublattices. Under certain growth conditions, the Cu and In atoms adopt an ordered configuration within the cationic sublattice resulting in the tetragonal chalcopyrite structure. Even when the deposition parameters are manipulated to produce nominally stoichiometric films, powder x-ray traces often exhibit anomalous peaks indicative of the presence of impurity phases. The identification of these minority phases by x-ray diffraction alone is not possible in this materials system due to low peak intensity and overlap considerations. The formation of the secondary phases has a detrimental effect on the electrical and optical properties of the thin film device.

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