New conductive IBAD buffer for HTS applications

2001 ◽  
Vol 689 ◽  
Author(s):  
Karola Thiele ◽  
Sibylle Sievers ◽  
Juergen Dzick ◽  
Lars-Oliver Kautschor ◽  
Christian Jooss ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Film Growth ◽  
Incident Angle ◽  
Texture Evolution ◽  
Ion Beam ◽  
Buffer Layers ◽  
Electrically Conductive ◽  
Ito Thin Films ◽  
Beam Parameters

ABSTRACTBiaxially aligned Indium Tin Oxide (ITO) thin films to be used as electrically conductive buffer layers were prepared by an Ion-Beam Assisted Deposition (IBAD) process on various substrates. Two Kaufman ion sources with 2.5 cm diameter were employed for the assisting and the sputtering beam, respectively. All deposited films revealed (001) oriented film growth with a strong in-plane alignment. The degree of the in-plane orientation was studied depending on the ion-beam parameters and the incident angle. Investigations (TEM and X-ray) of the texture evolution of these IBAD films during film growth were carried out. An in-plane texture of 12.6°FWHM for a 1 μm thick film has been achieved so far. The quality of the buffer has been demonstrated by the subsequent deposition of high-current carrying YBCO-films deposited by thermal coevaporation using a 3–5 nm thick Y2O3 interlayer. A jc of 0.76 MA/cm2 (77K, 0T) has been obtained for a 1 cm × 1 cm sample with ITO of 20° FWHM.

Room-temperature preparation of biaxially textured indium tin oxide thin films with ion-beam-assisted deposition

2003 ◽  
Vol 18 (2) ◽  
pp. 442-447 ◽  
Author(s):  
Karola Thiele ◽  
Sibylle Sievers ◽  
Christian Jooss ◽  
Jörg Hoffmann ◽  
Herbert C. Freyhardt
Keyword(s):  
Thin Films ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Room Temperature ◽  
Film Growth ◽  
Texture Evolution ◽  
Ion Beam ◽  
High Temperature Superconductors ◽  
Buffer Layers ◽  
Ito Thin Films

Biaxially aligned indium tin oxide (ITO) thin films were prepared by an ion-beamassisted deposition (IBAD) process at room temperature. Films with a transmittance at 550 nm of 90% and an electrical resistivity of 1.1 × 10−3 Ωcm for 300 and 250 nm thickness were obtained. Investigations of the texture evolution during IBAD film growth were carried out and compared to the well-established texture development in yttria-stabilized zirconia. An in-plane texture of 12.6° full width at half-maximum (FWHM) for a 1-μm-thick IBAD-ITO film was achieved. The quality of these films as electrically conductive buffer layers for YBa2Cu3O7-δ (YBCO) high-temperature superconductors was demonstrated by the subsequent deposition of high-currentcarrying YBCO films by thermal co-evaporation using a 3–5-nm-thick Y2O3 interlayer.A Jc of 0.76 MA/cm2 (77K, 0 T) was obtained for a 1 × 1 cm sample with ITO of 20° FWHM.

Characterization of Alumina Optical Waveguides Grown by Ion Beam Assisted Deposition for SPARROW Biosensors

2006 ◽  
Vol 967 ◽  
Author(s):  
Praneetha Poloju ◽  
P. K. Samudrala ◽  
J. R. Nightingale ◽  
D. Korakakis ◽  
L. A. Hornak
Keyword(s):  
Optical Waveguides ◽  
Ion Beam ◽  
Biomolecular Detection ◽  
Alumina Films ◽  
Optical Film ◽  
Optical Films ◽  
Beam Parameters ◽  
Coupling Characteristics

ABSTRACTDielectric optical films with minimal surface roughness are required for biosensing applications since the coupling characteristics often used in signal transduction are dependent on the quality of the waveguides. This paper describes the fabrication and characterization of alumina-based optical waveguides for biosensor device for biomolecular detection. Alumina (Aluminum Oxide) Al2O3waveguides were chosen for their moisture stability and refractive index. Planar alumina optical waveguides were deposited on Borofloat substrates by a vacuum evaporation process using an ion assisted electron beam deposition technique. The deposited films showed RMS roughness of 0.3nm – 0.5nm and a range of refractive indices varying from 1.62 to 1.654 as a function of varying ion beam parameters such as oxygen flow rates and drive currents. The propagation losses for the TE0(Transverse Electric) mode of the alumina films at 632.8nm wavelength were found to vary between 2dB/cm – 6dB/cm at a wavelength of 632.8nm for TE0polarization as a function of ion beam parameters. It is shown that these factors influence the optical film quality and hold the potential for achieving further waveguide performance improvement for biosensing applications.

scholarly journals Magnetic characterization of (001) and (111) Ni films epitaxially grown on MgO

2001 ◽  
Vol 674 ◽  
Author(s):  
R. A. Lukaszew ◽  
V. Stoica ◽  
R. Clarke
Keyword(s):  
Film Growth ◽  
Chemical Interaction ◽  
Hysteresis Loops ◽  
Magnetic Thin Films ◽  
Magnetic Films ◽  
Buffer Layers ◽  
Crystalline Quality ◽  
Silicon Substrates

ABSTRACTOne interesting application of epitaxial magnetic thin films is to use them as one of the electrodes in a spin-dependent tunneling junction, in order to use the magnetocrystalline anisotropy to define the required two states of the magnetization. [1] In our preliminary work, we prepared epitaxial magnetic films on copper buffer layers grown on silicon substrates. [2] The single crystalline quality of the films was particularly evident in the magnetization hysteresis loops, showing a sharp reversal at fairly high fields (120 Oe), when the samples were magnetized along the crystallographic easy axis. One technological disadvantage in this type of samples is the chemical interaction between the metallic layers and the silicon substrate.In order to explore the possibility of epitaxial magnetic films on less reactive substrates, we studied the growth on MgO substrates. We have shown that it is possible to obtain epitaxial (001) and (111) Ni films grown on MgO substrates. [3] In particular we observed that the crystalline quality of the films improved considerably after 10 nm of film growth. We will now present our studies on the magnetic properties of these films, particularly the azimuthal dependence of the magnetization reversal using MOKRE, correlating our finding with the structural characterization obtained with RHEED, STM and XRD.

scholarly journals Transparent Microelectrode Arrays Fabricated by Ion Beam Assisted Deposition for Neuronal Cell In Vitro Recordings

Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 497 ◽  
Author(s):  
Tomi Ryynänen ◽  
Ropafadzo Mzezewa ◽  
Ella Meriläinen ◽  
Tanja Hyvärinen ◽  
Jukka Lekkala ◽  
...  
Keyword(s):  
Thin Films ◽  
Indium Tin Oxide ◽  
Microelectrode Array ◽  
Electrode Materials ◽  
Ion Beam ◽  
Neuronal Cell ◽  
Measurement Properties ◽  
Ito Thin Films ◽  
Sputter Deposited

Microelectrode array (MEA) is a tool used for recording bioelectric signals from electrically active cells in vitro. In this paper, ion beam assisted electron beam deposition (IBAD) has been used for depositing indium tin oxide (ITO) and titanium nitride (TiN) thin films which are applied as transparent track and electrode materials in MEAs. In the first version, both tracks and electrodes were made of ITO to guarantee full transparency and thus optimal imaging capability. In the second version, very thin (20 nm) ITO electrodes were coated with a thin (40 nm) TiN layer to decrease the impedance of Ø30 µm electrodes to one third (1200 kΩ → 320 kΩ) while maintaining (partial) transparency. The third version was also composed of transparent ITO tracks, but the measurement properties were optimized by using thick (200 nm) opaque TiN electrodes. In addition to the impedance, the optical transmission and electric noise levels of all three versions were characterized and the functionality of the MEAs was successfully demonstrated using human pluripotent stem cell-derived neuronal cells. To understand more thoroughly the factors contributing to the impedance, MEAs with higher IBAD ITO thickness as well as commercial sputter-deposited and highly conductive ITO were fabricated for comparison. Even if the sheet-resistance of our IBAD ITO thin films is very high compared to the sputtered one, the impedances of the MEAs of each ITO grade were found to be practically equal (e.g., 300–370 kΩ for Ø30 µm electrodes with 40 nm TiN coating). This implies that the increased resistance of the tracks, either caused by lower thickness or lower conductivity, has hardly any contribution to the impedance of the MEA electrodes. The impedance is almost completely defined by the double-layer interface between the electrode top layer and the medium including cells.

Sputter Deposited, Electrically Conductive, Oxidation Resistant Coatings

1985 ◽  
Vol 54 ◽  
Author(s):  
Sharon K. Rutledge
Keyword(s):  
Indium Tin Oxide ◽  
Electromagnetic Interference ◽  
Atomic Oxygen ◽  
Ion Beam ◽  
Space Plasma ◽  
Polymer Materials ◽  
Electrically Conductive ◽  
Solar Arrays ◽  
Oxidation Resistant ◽  
Sputter Deposited

ABSTRACTSignificant polymer weight loss has been observed due to environmental ashing by atomic oxygen at low earth orbital (LEO) altitudes. Static charging during deployment and charging caused by the space plasma in LEO polar orbits may cause electromagnetic interference (EMI) problems on insulating polymer materials that are integral to such applications as high voltage solar arrays. Simultaneous ion beam sputter deposited coatings of indium-tin-oxide (ITO) with polytetrafluoroethylene (PTFE), carbon, air, or methane were investigated as potential solutions to these problems. The purpose of this research was to improve the flexibility of ITO coatings with these additives and to study the effect the addition of these materials had not only on the flexibility of ITO sputter deposited thin films but also on the conductivity and optical properties.

Effect of Emitting Current Ion Source on Structural, Optical and Electrical Properties of Nanostructured ITO Thin Films by Ion-Beam Assisted Evaporation

2014 ◽  
Vol 979 ◽  
pp. 263-266 ◽  
Author(s):  
Bhumin Yosvichit ◽  
Mati Horprathum ◽  
Pitak Eiamchai ◽  
Viyapol Patthanasetakul ◽  
Benjarong Samransuksamer ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Carrier Concentration ◽  
Indium Tin Oxide ◽  
Ion Beam ◽  
Ion Source ◽  
Optical And Electrical Properties ◽  
Substrate Heating ◽  
Ito Thin Films ◽  
Ito Films

Transparent conductive oxides (TCOs) with indium tin oxide (ITO) thin films were deposited without substrate heating and post-deposition anneal using ion-beam assisted evaporation technique on glass and silicon substrates. The oxygen ion with emitting current produced using End-Hall ion source for bombardment of growing surface to improve ITO films structure. In this study, we investigate the effect of an ion flux to ITO films in terms of structural, optical and electrical properties. The emitting current can be varied from 0.5 to 2.0 A with the oxygen flow rate 7 sccm. The total film thickness and deposition rate are 200 nm and 0.2 nm/s, respectively. The structural properties of thin films were characterized by X-ray diffraction (XRD) to discover the preferred orientation with phase of crystalline and scanning electron microscopy (SEM) to examine the surface morphology in cross-section view. To determine the transmission spectra of the films, UV-visible spectrometer is introduced. Moreover, the films were also measured to investigate resistivity, carrier concentration, mobility and sheet resistance by Hall-effect measurements and four-point probe. It has been found that the ITO films with lowest electrical resistivity for the emitting current of 1 A about 5.57x10-4 Ω.cm and slightly increases with increase of the emitting current. The mobility and carrier concentration rapidly decreases with increase the emitting current from 1.0 A to 2.0 A.

Low Electrically Resistive Transparent Indium-Tin-Oxide Epitaxial Film on (001) Surface of YSZ by Pulsed Laser Deposition

2000 ◽  
Vol 623 ◽  
Author(s):  
Hiromichi Ohta ◽  
Masahiro Orita ◽  
Masahiro Hirano ◽  
Hideo Hosono ◽  
Hiroshi Kawazoe ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Epitaxial Film ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Flat Substrate ◽  
Ito Thin Films ◽  
Almost All

AbstractHigh quality ITO thin films were grown hetero-epitaxially on extremely flat substrate of (001) YSZ by a pulsed laser deposition technique at a substrate temperature of 600°C. The crystal orientation relationship between the film and YSZ were confirmed as ITO (001) // YSZ (001) and ITO (010) // YSZ (010), respectively, by HR-XRD and HR-TEM. The carrier densities of the films were almost equal to Sn02 concentration in the films. That is, almost all the doped Sn4+ ions were activated to release electrons to the conduction band. The carrier densities of the films were enhanced up to 1.9×1021cm−3, while the Hall mobility showed a slight, almost linear, decrease from 55 to 40cm2V−1s−1 with increasing SnO2 concentration. The low resistivity is due to larger electron mobility, which most likely resulted from good crystal quality of the films. The optical transmissivity of the film exceeded 85% at wavelengths from 340 to 780nm.

Ion Beam Assisted Deposition

2003 ◽  
Vol 792 ◽  
Author(s):  
James K. Hirvonen
Keyword(s):  
Thin Film ◽  
Physical Vapor Deposition ◽  
Film Growth ◽  
Ion Beam ◽  
Buffer Layers ◽  
Optical Coatings ◽  
Temperature Sensitive ◽  
Energetic Ions ◽  
Ion Beam Assisted Deposition ◽  
Tribological Coatings

ABSTRACTThe beneficial roles energetic ions play in thin film vacuum processes have long been recognized by the vacuum coating community. Optical coaters were among the first to adopt the process in the form of concurrent, low energy, directed ion beam bombardment of physical vapor deposition [electron beam] coatings for producing dense, adherent, robust, and environmentally resistant optical coatings. The international research and development community has also been actively pursuing the study of ion beam assisted deposition (IBAD) for both studying the mechanisms of ion/solid interactions during thin film growth as well as for developing coating protocols for specific application areas, including: tribological coatings, anti-corrosion coatings, optical coatings, superconducting buffer layers and coatings for temperature sensitive substrates such as polymers. This paper will review selected areas of this active field and will attempt to identify emerging application areas.

Biaxially-Textured YBa2Cu3O7–x Thin Film Growth on Polycrystalline and Amorphous Substrates Using Ion Assisted Laser Deposition of Yttria-Stabilized Zirconia Intermediate Layers

1992 ◽  
Vol 285 ◽  
Author(s):  
R. P. Reade ◽  
P. Berdahl ◽  
R. E. Russo ◽  
S. M. Garrison
Keyword(s):  
Thin Film ◽  
Film Growth ◽  
Incident Angle ◽  
Ion Beam ◽  
Yttria Stabilized Zirconia ◽  
Thin Film Growth ◽  
Laser Deposition ◽  
Stabilized Zirconia ◽  
Polycrystalline Alumina ◽  
Intermediate Layers

ABSTRACTThe growth of (001)-textured, biaxially-aligned yttria-stabilized zirconia (YSZ) intermediate layers on amorphous or randomly-oriented polycrystalline substrates is desirable for subsequent YBa2Cu3O7–x (YBCO) c-axis thin film growth. Laser deposition of YSZ on polycrystalline metal substrates (Haynes Alloy #230) in 1.0 millitorr oxygen at 70°C produces partial (001) texture but no alignment of in-plane axes. Highly-textured biaxially-aligned layers are obtained by using an ion beam to assist growth. Similar layers are obtained on amorphous silica and polycrystalline alumina substrates. The effects of ion-beam parameters including incident angle, source gas, and beam voltage and current are presented. Highly c-axis-oriented, biaxiallyaligned YBCO thin films have been deposited in situ on these YSZ layers, with Tc(R=0) ∼ 92K and Jc(77K) = 6 × 105 A/cm2. Angular magnetoresistance data shows a dip in resistance with magnetic field normal to the film, in contrast to films grown epitaxially on single crystal substrates, which have maximum resistance with field normal.

Effects of Susceptor Geometry on GaN Growth on SI(111) with a New Mocvd Reactor

1998 ◽  
Vol 537 ◽  
Author(s):  
Yungeng Gao ◽  
Daniel A. Gulino ◽  
Ryan Higgins
Keyword(s):  
Single Crystal ◽  
Film Growth ◽  
Chemical Species ◽  
Buffer Layers ◽  
Structural Quality ◽  
Growth Pressure ◽  
Rocking Curve ◽  
X Ray ◽  
Mocvd Reactor

AbstractHigh quality GaN films on AIN buffer layers were grown on Si(111) with a new, commercial, two-injector vertical rotating disk MOCVD reactor (CVD, Inc.). It was found that the geometry of the susceptor greatly affected the structural quality of the epilayers on Si. For the original susceptor geometry, though single crystal GaN films could be obtained, the films were dark gray in appearance with a rough morphology, and the best x-ray rocking curve FWHM was 2.33°. After modifying the susceptor geometry, transparent, mirror-like single crystal GaN films were obtained with the best x-ray rocking curve FWHM being 0.24°. Photoluminescence (PL) and infrared reflectance (IR) spectra of the grown films were compared. The film growth rate was found to increase with decrease of the growth pressure. A 2-D simulation of the flow, heat transfer, and chemical species transport in the reactor showed a more symmetric flow, larger velocity gradient, and lower upward velocity with the modified susceptor, which may be the main reason for the improvement of the structural quality of the films.

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