APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Next Issue

3 Jul 2006

Volume 89, Issue 1, Articles (01xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 89, 011901 (2006); http://dx.doi.org/10.1063/1.2218670 (3 pages)

L. S. Wang, S. Tripathy, B. Z. Wang, J. H. Teng, S. Y. Chow, and S. J. Chua
Enlarge Image | Read More
Page 2 of 4 Pages Previous Page Next Page | Jump to Page
back to top
RSS Feeds

Growth of Mg–Al spinel microcrystals on a sapphire surface using a solution-precipitation method

Che-Ming Liu and Jyh-Chen Chen

Appl. Phys. Lett. 89, 011912 (2006); http://dx.doi.org/10.1063/1.2220062 (3 pages)

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A solution-precipitation process was used to grow Mg–Al spinel microcrystals at etched pits in a c-axial sapphire single crystal surface. In the proposed innovative growth process, the etched pits function as heterogeneous nucleation points. The quenching and aging treatment causes Mg ions to diffuse into the sapphire crystal, precipitating as microcrystals at the etched pits. We found the precipitated crystals to be (111) Mg–Al spinels with a triangular pyramidal shape.
Show PACS
81.10.Dn Growth from solutions
64.75.-g Phase equilibria
81.30.Mh Solid-phase precipitation
81.10.Fq Growth from melts; zone melting and refining
81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
68.35.B- Structure of clean surfaces (and surface reconstruction)
61.66.Fn Inorganic compounds

Thermal stress evolution in embedded Cu/low-k dielectric composite features

Conal E. Murray, Charles C. Goldsmith, Thomas M. Shaw, James P. Doyle, and I. C. Noyan

Appl. Phys. Lett. 89, 011913 (2006); http://dx.doi.org/10.1063/1.2219727 (3 pages) | Cited 5 times

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
To determine the effect of low-modulus materials on the thermal stress evolution within interconnect metallization, thermal and residual stresses in copper features, embedded in an organosilicate glass (SiCOH) on a silicon substrate, were measured by x-ray diffraction as a function of temperature and calculated using finite element modeling. The elastic response of the structures was dictated by the thermal expansion mismatch between copper and silicon, the copper and SiCOH elastic moduli, and the composite geometry. The presence of a low-modulus layer between the features and underlying substrate plays a major role in the elastic stress relaxation generated during thermal cycling.
Show PACS
81.05.Mh Cermets, ceramic and refractory composites
85.40.Ls Metallization, contacts, interconnects; device isolation
81.40.Jj Elasticity and anelasticity, stress-strain relations
62.20.D- Elasticity
68.60.Bs Mechanical and acoustical properties
65.40.De Thermal expansion; thermomechanical effects

Insights into the origin of threading dislocations in GaN/Al2O3 from atomic force microscopy

Rachel A. Oliver, Menno J. Kappers, and Colin J. Humphreys

Appl. Phys. Lett. 89, 011914 (2006); http://dx.doi.org/10.1063/1.2219747 (3 pages) | Cited 14 times

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Threading dislocations in GaN/Al2O3 are widely assumed to arise at the coalescence boundaries of misoriented islands. We have used atomic force microscopy to study a large number of coalescence boundaries and found no significant difference between the threading dislocation density in the boundary regions and the overall threading dislocation density for the large islands observed on partially coalesced samples. A secondary population of smaller islands is observed with a significantly higher dislocation density, and we suggest that when these small islands are overgrown by large islands, these threading dislocations are incorporated into the large islands, resulting in dislocation clusters.
Show PACS
61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)
68.37.Ps Atomic force microscopy (AFM)
68.35.B- Structure of clean surfaces (and surface reconstruction)
back to top
RSS Feeds

Low-resistance p+ layer formation into diamond using heavily B ion implantation

Nobuteru Tsubouchi, Masahiko Ogura, Yuji Horino, and Hideyo Okushi

Appl. Phys. Lett. 89, 012101 (2006); http://dx.doi.org/10.1063/1.2219088 (3 pages) | Cited 7 times

Online Publication Date: 5 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We examine the B dosage dependence of the lattice and electronic structures of a heavily B doped layer formed by multiple-energy B-implantation into diamond (up to 1.7×1017 B cm−2) at an elevated temperature. The resultant highly B doped diamond layer exhibits p-type conduction with very low sheet resistance of 90 Ω/◻ (0.25 μm thickness) and low resistivity of 2.3 mΩ cm and has temperature-independent transport properties. This suggests that a high-temperature ion implantation technique allows the formation of diamond as a p-type degenerate semiconductor with metallic conduction and provides a useful tool for selective doping required for practical diamond device processing.
Show PACS
81.05.Cy Elemental semiconductors
73.61.Cw Elemental semiconductors
61.72.up Other materials
71.20.Mq Elemental semiconductors
68.55.-a Thin film structure and morphology

Annealing-time dependence in interfacial reaction between poly-Si electrode and HfO2/Si gate stack studied by synchrotron radiation photoemission and x-ray absorption spectroscopy

H. Takahashi, J. Okabayashi, S. Toyoda, H. Kumigashira, M. Oshima, K. Ikeda, G. L. Liu, Z. Liu, and K. Usuda

Appl. Phys. Lett. 89, 012102 (2006); http://dx.doi.org/10.1063/1.2219126 (3 pages) | Cited 6 times

Online Publication Date: 6 July 2006

Full Text: Read Online (HTML) | Download PDF


See Also: Erratum

Show Abstract
We have investigated annealing-time dependence in interfacial reactions between polycrystalline-Si (poly-Si) electrodes and HfO2/Si gate stacks using synchrotron radiation photoemission and x-ray absorption spectroscopy. From photoemission core-level spectra, we found that silicidation started at the upper interface between poly-Si electrodes and HfO2 gate dielectrics under the conditions of 700 °C and 3 min in ultrahigh vacuum. Before silicidation, we observed nonstoichiometric silicon oxide at the upper interface, suggesting the formation of oxygen vacancies which may cause Fermi level pinning. The interface layer between HfO2 gate dielectrics and Si substrates was changed into silicide by further annealing. In addition, from valence-band photoemission and O K-edge absorption spectra, we have found that the crystallization of HfO2 gate dielectrics is independent of silicidation.
Show PACS
61.72.Cc Kinetics of defect formation and annealing
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
79.60.Jv Interfaces; heterostructures; nanostructures
78.70.Dm X-ray absorption spectra
73.20.At Surface states, band structure, electron density of states
64.70.K- Solid-solid transitions

Bias voltage dependence of the electron spin injection studied in a three-terminal device based on a (Ga,Mn)As/n+-GaAs Esaki diode

M. Kohda, T. Kita, Y. Ohno, F. Matsukura, and H. Ohno

Appl. Phys. Lett. 89, 012103 (2006); http://dx.doi.org/10.1063/1.2219141 (3 pages) | Cited 23 times

Online Publication Date: 6 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We investigated injection of spin polarized electrons in a (Ga,Mn)As/n+-GaAs Esaki diode (ED) by using a three-terminal device integrating a (Ga,Mn)As ED and a light emitting diode (LED). Electroluminescence polarization (PEL) from the LED was measured under the Faraday configuration as a function of bias voltages applied independently to the Esaki diode and to the LED. The maximum PEL of 32.4% was observed when the valence electrons near the Fermi energy of (Ga,Mn)As are ballistically injected into the LED.
Show PACS
85.30.Mn Junction breakdown and tunneling devices (including resonance tunneling devices)
85.60.Jb Light-emitting devices

Polypyrrole thin-film field-effect transistor

C. C. Bof Bufon and T. Heinzel

Appl. Phys. Lett. 89, 012104 (2006); http://dx.doi.org/10.1063/1.2219375 (3 pages) | Cited 10 times

Online Publication Date: 6 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The operation of a polypyrrole thin-film field-effect transistor at room temperature is reported. The polymer film is prepared by a technique based on chemical polymerization, which is capable of forming thin films with low roughness. The technique is compatible with conventional silicon processing and allows a lithographic definition of the polymer film geometry. Transport measurements indicate that the device works as Schottky barrier-type field-effect transistor. We further demonstrate that the polymer film is sensitive to oxygen exposure.
Show PACS
85.30.Tv Field effect devices
85.40.Hp Lithography, masks and pattern transfer
73.30.+y Surface double layers, Schottky barriers, and work functions

Switching effect in spin field-effect transistors

K. M. Jiang, Z. M. Zheng, Baigeng Wang, and D. Y. Xing

Appl. Phys. Lett. 89, 012105 (2006); http://dx.doi.org/10.1063/1.2219742 (3 pages) | Cited 15 times

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We study how the conductance of a spin field-effect transistor (SFET) is manipulated by spin-orbit coupling strength, interfacial barrier height, and spin polarization in source and drain. It is shown that the conductance of the SFET exhibits an excellent switching characteristic for high potential barriers. By tuning the split-gate voltage one can vary the Dresselhaus [Phys. Rev. 100, 580 (1955) ] spin-orbit coupling strength so as to switch the SFET on or off. On the other hand, in the SFET with almost Ohmic-contact interfaces there is pronounced conductance modulation mainly due to the Rashba [Sov. Phys. Solid State 2, 1190 (1960) ] and Dresselhaus spin precession.
Show PACS
85.75.Hh Spin polarized field effect transistors

Electrical characterization of GaAs metal bonded to Si

Justin R. Bickford, D. Qiao, P. K. L. Yu, and S. S. Lau

Appl. Phys. Lett. 89, 012106 (2006); http://dx.doi.org/10.1063/1.2219980 (3 pages) | Cited 1 time

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Wafer bonding has traditionally focused on producing either insulating or nonlinear heterostructure interfaces; low-resistance Ohmic interfaces would offer the advantage of more efficient current delivery. In this study, doped GaAs was bonded to doped Si using indium and palladium interlayers. During heating above the lower melting point metal indium, a solid alloy is formed bonding the GaAs and Si together, this process is typically referred to as isothermal solidification. This method universally created Ohmic bond interfaces for all doping types. A metric was devised to measure the bond resistivity revealing a resistivity of 1.03×10−5 Ω cm2 for n-GaAs bonded to p-Si.
Show PACS
73.40.Vz Semiconductor-metal-semiconductor structures
81.40.Gh Other heat and thermomechanical treatments
81.30.Fb Solidification

Origin of the enhanced performance in poly(3-hexylthiophene): [6,6]-phenyl C61-butyric acid methyl ester solar cells upon slow drying of the active layer

Valentin D. Mihailetchi, Hangxing Xie, Bert de Boer, Lacramioara M. Popescu, Jan C. Hummelen, Paul W. M. Blom, and L. Jan Anton Koster

Appl. Phys. Lett. 89, 012107 (2006); http://dx.doi.org/10.1063/1.2212058 (3 pages) | Cited 105 times

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The origin of the enhanced performance of bulk heterojunction solar cells based on slowly dried films of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester is investigated, combining charge transport measurements with numerical device simulations. Slow drying leads to a 33-fold enhancement of the hole mobility up to 5.0×10−7 m2 V−1 s−1 in the P3HT phase of the blend, thereby balancing the transport of electrons and holes in the blend. The resulting reduction of space-charge accumulation enables the use of thick films ( ∼ 300 nm), absorbing most of the incoming photons, without losses in the fill factor and short-circuit current of the device.
Show PACS
84.60.Jt Photoelectric conversion
81.05.Lg Polymers and plastics; rubber; synthetic and natural fibers; organometallic and organic materials
81.05.ub Fullerenes and related materials
73.61.Ph Polymers; organic compounds
73.61.Wp Fullerenes and related materials
85.30.De Semiconductor-device characterization, design, and modeling

Current spin-polarization in an inhomogeneous semiconductor

L. Villegas-Lelovsky

Appl. Phys. Lett. 89, 012108 (2006); http://dx.doi.org/10.1063/1.2219410 (3 pages) | Cited 2 times

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We investigate the spin-resolved transient dynamics of spin-polarized carriers injected via a ferromagnetic scanning-tunneling-microscope tip into nonuniformly n-doped bulk semiconductor externally driven by a current source. We propagate the injected spin packets by considering a spin hydrodynamic approach based on balance equations directly derived from a spin-dependent Boltzmann equation. We determine the spin polarization profiles for carrier and current densities. While the carrier spin polarization shows a drastic suppression in the interface the current spin polarization exhibits an enhancement.
Show PACS
72.80.Ey III-V and II-VI semiconductors
72.25.Dc Spin polarized transport in semiconductors
back to top
RSS Feeds

Search for ferromagnetism in conductive Nb:SrTiO3 with magnetic transition element (Cr, Co, Fe, Mn) dopants

S. X. Zhang, S. B. Ogale, Darshan C. Kundaliya, L. F. Fu, N. D. Browning, S. Dhar, W. Ramadan, J. S. Higgins, R. L. Greene, and T. Venkatesan

Appl. Phys. Lett. 89, 012501 (2006); http://dx.doi.org/10.1063/1.2219145 (3 pages) | Cited 10 times

Online Publication Date: 5 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Thin films of (0.5%, 1%) Nb:SrTiO3 dilutely doped with (2 at. %) magnetic transition elements (Cr, Co, Fe, Mn) are examined for ferromagnetism. X-ray diffraction, Rutherford backscattering ion channeling, scanning transmission electron microscopy Z-contrast imaging, and electron energy loss spectroscopy techniques establish high crystalline quality of the films with no impurity phase(s) and highly uniform dopant distribution. Although the film conductivity improves dramatically by Nb doping, no ferromagnetism is found in any of our samples over the temperature range of 365 down to 5 K. This is contrasted to the case of ferromagnetism reported in cobalt doped (La,Sr)TiO3.
Show PACS
75.70.Ak Magnetic properties of monolayers and thin films
75.50.Pp Magnetic semiconductors
75.50.Dd Nonmetallic ferromagnetic materials
75.30.Hx Magnetic impurity interactions
68.37.Lp Transmission electron microscopy (TEM)

Inverted spin polarization of Heusler alloys for spintronic devices

Andy Thomas, Dirk Meyners, Daniel Ebke, Ning-Ning Liu, Marc D. Sacher, Jan Schmalhorst, Günter Reiss, Hubert Ebert, and Andreas Hütten

Appl. Phys. Lett. 89, 012502 (2006); http://dx.doi.org/10.1063/1.2219333 (3 pages) | Cited 14 times

Online Publication Date: 6 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A magnetic logic concept overcomes the major limitations of field programmable gate arrays while having a 50% smaller unit cell than conventional designs utilizing magnetic tunnel junctions with one Heusler alloy electrode. These show positive and negative tunneling magnetoresistance values at different bias voltages at room temperature which generally add an additional degree of freedom to all spintronic devices.
Show PACS
85.75.-d Magnetoelectronics; spintronics: devices exploiting spin polarized transport or integrated magnetic fields
85.70.Kh Magnetic thin film devices: magnetic heads (magnetoresistive, inductive, etc.); domain-motion devices, etc.
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
72.25.Mk Spin transport through interfaces

Minute doping with deleterious rare earths in YBa2Cu3O7−δ films for flux pinning enhancements

P. N. Barnes, J. W. Kell, B. C. Harrison, T. J. Haugan, C. V. Varanasi, M. Rane, and F. Ramos

Appl. Phys. Lett. 89, 012503 (2006); http://dx.doi.org/10.1063/1.2219391 (3 pages) | Cited 13 times

Online Publication Date: 6 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
To enhance the critical current density of YBa2Cu3O7−δ films, flux pinning centers are intentionally added to inhibit flux flow in applied magnetic fields. Here we provide an initial demonstration that the incorporation of very minor additions ( ⩽ 1% of Y as opposed to the 10%–40% in standard substitutions) of typically deleterious rare earths into high quality YBa2Cu3O7−δ thin films provides significant improvement of the film’s in-field current density. This is accomplished without reoptimization of the deposition parameters. Instead of site substitution for Y as might be expected, the deleterious rare earths potentially result in the formation of nanoparticulates.
Show PACS
74.78.-w Superconducting films and low-dimensional structures
74.72.-h Cuprate superconductors
61.72.up Other materials
74.25.Uv Vortex phases (includes vortex lattices, vortex liquids, and vortex glasses)
74.25.Sv Critical currents

Mn L3,2 x-ray absorption and magnetic circular dichroism in ferromagnetic Ga1−xMnxP

P. R. Stone, M. A. Scarpulla, R. Farshchi, I. D. Sharp, E. E. Haller, O. D. Dubon, K. M. Yu, J. W. Beeman, E. Arenholz, J. D. Denlinger, and H. Ohldag

Appl. Phys. Lett. 89, 012504 (2006); http://dx.doi.org/10.1063/1.2219713 (3 pages) | Cited 12 times

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have measured the x-ray absorption and x-ray magnetic circular dichroism (XMCD) at the Mn L3,2 edges in ferromagnetic Ga1−xMnxP films for 0.018 ⩽ x ⩽ 0.042. Large XMCD asymmetries at the L3 edge indicate significant spin polarization of the density of states at the Fermi energy. The temperature dependence of the XMCD and moment per Mn of 2.67±0.45μB calculated using sum rules are consistent with magnetometry values. The spectral shapes of the x-ray absorption and XMCD are nearly identical with those for Ga1−xMnxAs indicating that the hybridization of Mn d states and anion p states is similar in the two materials.
Show PACS
78.70.Dm X-ray absorption spectra
78.20.Ls Magneto-optical effects
75.50.Pp Magnetic semiconductors
75.50.Dd Nonmetallic ferromagnetic materials
75.30.Cr Saturation moments and magnetic susceptibilities
75.70.Ak Magnetic properties of monolayers and thin films

Diffusion and clustering of substitutional Mn in (Ga,Mn)As

Hannes Raebiger, Maria Ganchenkova, and Juhani von Boehm

Appl. Phys. Lett. 89, 012505 (2006); http://dx.doi.org/10.1063/1.2219337 (3 pages) | Cited 12 times

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The Ga vacancy mediated microstructure evolution of (Ga,Mn)As during growth and postgrowth annealing is studied using a multiscale approach. The migration barriers for the Ga vacancies and substitutional Mn together with their interactions are calculated using first principles, and temporal evolution at temperatures 200–350 °C is studied using lattice kinetic Monte Carlo simulations. We show that at the typical growth and annealing temperatures (i) Ga vacancies provide an efficient diffusion transport for Mn and (ii) in 10–20 h the diffusion of Mn promotes the formation of clusters. Clustering reduces the Curie temperature, and explains its decrease during long-term annealing.
Show PACS
66.30.J- Diffusion of impurities
66.30.Lw Diffusion of other defects
61.72.J- Point defects and defect clusters
61.72.Cc Kinetics of defect formation and annealing

Multifilament YBa2Cu3O6+x-coated conductors with minimized coupling losses

G. A. Levin, P. N. Barnes, J. W. Kell, N. Amemiya, Z. Jiang, K. Yoda, and F. Kimura

Appl. Phys. Lett. 89, 012506 (2006); http://dx.doi.org/10.1063/1.2219393 (3 pages) | Cited 9 times

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report an experimental approach to making multifilament coated conductors with low losses in applied time-varying magnetic field. Previously, the multifilament conductors obtained for that purpose by laser ablation suffered from high coupling losses. Here we report how this problem can be solved. When the substrate metal in the grooves segregating the filaments is exposed to oxygen, it forms high resistivity oxides that electrically insulate the stripes from each other and from the substrate. As the result, the coupling loss has become negligible over the entire range of tested parameters (magnetic field amplitudes B and frequencies f).
Show PACS
74.72.-h Cuprate superconductors
81.65.-b Surface treatments
81.40.Gh Other heat and thermomechanical treatments
42.62.-b Laser applications

Magnetic anisotropy of Ga1−xMnxAs thin films on GaAs (311)A probed by ferromagnetic resonance

C. Bihler, H. Huebl, M. S. Brandt, S. T. B. Goennenwein, M. Reinwald, U. Wurstbauer, M. Döppe, D. Weiss, and W. Wegscheider

Appl. Phys. Lett. 89, 012507 (2006); http://dx.doi.org/10.1063/1.2219408 (3 pages) | Cited 14 times

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have studied the magnetic anisotropy of Ga1−xMnxAs thin films grown by low-temperature molecular beam epitaxy on GaAs (311)A substrates by means of ferromagnetic resonance spectroscopy. The angular dependence of the ferromagnetic resonance fields observed can be explained by two main contributions to the magnetic anisotropy: a cubic magnetic anisotropy field oriented along the crystallographic ⟨001⟩ axes caused by the symmetry of the GaAs host lattice, and an effective uniaxial magnetic anisotropy field along [311] presumably caused by the homoepitaxial growth of the layer. Additional smaller magnetic anisotropy contributions are discussed. Consequently, the dominating magnetic anisotropy of Ga1−xMnxAs on GaAs (311)A substrate appears to have the same origin as on GaAs (100) substrate.
Show PACS
75.50.Pp Magnetic semiconductors
75.50.Dd Nonmetallic ferromagnetic materials
75.70.Ak Magnetic properties of monolayers and thin films
75.30.Gw Magnetic anisotropy
76.50.+g Ferromagnetic, antiferromagnetic, and ferrimagnetic resonances; spin-wave resonance

Ferromagnetism in Fe-implanted a-plane ZnO films

P. Wu, G. Saraf, Y. Lu, D. H. Hill, R. Gateau, L. Wielunski, R. A. Bartynski, D. A. Arena, J. Dvorak, A. Moodenbaugh, T. Siegrist, J. A. Raley, and Yung Kee Yeo

Appl. Phys. Lett. 89, 012508 (2006); http://dx.doi.org/10.1063/1.2213519 (3 pages) | Cited 21 times

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Fe ions of dose 5×1016 cm−2 were implanted at 200 keV into a-plane ZnO epitaxial films. The epitaxial quality of the postannealed samples was verified by x-ray diffraction ω-rocking curves and φ scans, whereas x-ray absorption spectroscopy identified the presence of both Fe2+ and Fe3+ ions, as well as changes in their relative concentration during postannealing. Superconducting quantum interference device measurements show that the as-implanted and postannealed films are ferromagnetic at room temperature. The saturation magnetization reduces during annealing possibly due to the decrease in the number of oxygen vacancies.
Show PACS
75.50.Pp Magnetic semiconductors
75.50.Dd Nonmetallic ferromagnetic materials
61.72.up Other materials
61.72.Cc Kinetics of defect formation and annealing
78.70.Dm X-ray absorption spectra
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
back to top
RSS Feeds

Piezoelectricity of A3BC3D2O14 structure crystals

Jianjun Chen, Yanqing Zheng, Haikuan Kong, and Erwei Shi

Appl. Phys. Lett. 89, 012901 (2006); http://dx.doi.org/10.1063/1.2219123 (3 pages) | Cited 5 times

Online Publication Date: 5 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
First-principle calculations are performed to reveal the microscopic origin of piezoelectricity of ordered crystals with A3BC3D2O14 structure. The calculated piezoelectric constant e11 and atomistic piezoelectric contribution from every single atom type in a primitive cell of Sr3NbGa3Si2O14 (SNGS), Sr3TaGa3Si2O14 (STGS), Ca3NbGa3Si2O14 (CNGS), and Ca3TaGa3Si2O14 (CTGS) structures showed that the piezoelectricity comes mostly from one of three atoms in A positions. The percentages of the contributions from the A positions to the total internal piezoelectric constant exceed 69% in CNGS and CTGS and 81% in SNGS and STGS, respectively.
Show PACS
77.65.Bn Piezoelectric and electrostrictive constants
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.

Stabilization of the cubic phase of HfO2 by Y addition in films grown by metal organic chemical vapor deposition

E. Rauwel, C. Dubourdieu, B. Holländer, N. Rochat, F. Ducroquet, M. D. Rossell, G. Van Tendeloo, and B. Pelissier

Appl. Phys. Lett. 89, 012902 (2006); http://dx.doi.org/10.1063/1.2216102 (3 pages) | Cited 37 times

Online Publication Date: 5 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Addition of yttrium in HfO2 thin films prepared on silicon by metal organic chemical vapor deposition is investigated in a wide compositional range (2.0–99.5 at. %). The cubic structure of HfO2 is stabilized for 6.5 at. %. The permittivity is maximum for yttrium content of 6.5–10 at. %; in this range, the effective permittivity, which results from the contribution of both the cubic phase and silicate phase, is of 22. These films exhibit low leakage current density (5×10−7 A/cm2 at −1 V for a 6.4 nm film). The cubic phase is stable upon postdeposition high temperature annealing at 900 °C under NH3.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.55.-g Dielectric thin films
77.22.Ch Permittivity (dielectric function)
68.55.-a Thin film structure and morphology

Energy-band parameters of atomic-layer-deposition Al2O3/InGaAs heterostructure

M. L. Huang, Y. C. Chang, C. H. Chang, T. D. Lin, J. Kwo, T. B. Wu, and M. Hong

Appl. Phys. Lett. 89, 012903 (2006); http://dx.doi.org/10.1063/1.2218826 (3 pages) | Cited 31 times

Online Publication Date: 6 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The valence-band offset has been determined to be 3.83±0.05 eV at the atomic-layer-deposition Al2O3/InGaAs interface by x-ray photoelectron spectroscopy. The Au–Al2O3/InGaAs metal-oxide-semiconductor diode exhibits current-voltage characteristics dominated by Fowler-Nordheim tunneling. From the current-voltage data at forward and reverse biases, a conduction-band offset of 1.6±0.1 eV at the Al2O3–InGaAs interface and an electron effective mass ∼ 0.28±0.04m0 of the Al2O3 layer have been extracted. Consequently, combining the valence-band offset, the conduction-band offset, and the energy-band gap of the InGaAs, the energy-band gap of the atomic-layer-deposited Al2O3 is 6.65±0.11 eV.
Show PACS
73.20.At Surface states, band structure, electron density of states
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
79.60.Bm Clean metal, semiconductor, and insulator surfaces

Metal transport and loss in ultrathin hafnium aluminate films on silicon studied by low, medium, and high energy ion beam analyses

L. Miotti, C. Driemeier, F. Tatsch, C. Radtke, and I. J. R. Baumvol

Appl. Phys. Lett. 89, 012904 (2006); http://dx.doi.org/10.1063/1.2219150 (3 pages) | Cited 4 times

Online Publication Date: 6 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Metal transport and loss induced by thermal annealing in ultrathin HfAlxOy films deposited on Si by atomic layer deposition were investigated by ion beam analysis. It was observed that rapid thermal annealing at 1000 °C induces decomposition of the aluminate films leading to Hf and Al losses mainly into the gas phase. It was possible to avoid this undesired decomposition effect by performing a postdeposition nitridation in NH3 at 850 °C prior to the rapid thermal annealing step. The role of nitridation is discussed in terms of the profiles of incorporated N, before and after rapid thermal annealing, as determined by narrow resonant nuclear reaction profiling.
Show PACS
77.55.-g Dielectric thin films
81.05.-t Specific materials: fabrication, treatment, testing, and analysis
73.61.Ng Insulators
61.72.Cc Kinetics of defect formation and annealing
81.65.Lp Surface hardening: nitridation, carburization, carbonitridation
64.75.-g Phase equilibria

Thermochemical reaction of ZrOx(Ny) interfaces on Ge and Si substrates

Chao-Ching Cheng, Chao-Hsin Chien, Je-Hung Lin, Chun-Yen Chang, Guang-Li Luo, Chun-Hui Yang, and Shih-Lu Hsu

Appl. Phys. Lett. 89, 012905 (2006); http://dx.doi.org/10.1063/1.2219347 (3 pages) | Cited 2 times

Online Publication Date: 6 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have studied the thermochemical characteristics of ZrOx(Ny)/Ge and Si interfaces by employing postdeposition annealing. We found that Ge oxide species severely desorbed from the inherent interfacial layer, which was speculated to retard the formation of Zr germanate during high-temperature processing. These unique features enable ZrOx(Ny)/Ge gate stack to show a better equivalent-oxide-thickness scalability as compared to ZrOx(Ny)/Si gate stack. However, the volatilization of GeOx-contained interfacial layer also caused the formation of small pits and/or holes in the overlying ZrOx(Ny) gate dielectrics, which was expected to cause deterioration in the electrical properties of fabricated high-k/Ge devices.
Show PACS
77.55.-g Dielectric thin films
68.35.Fx Diffusion; interface formation
81.40.Gh Other heat and thermomechanical treatments
68.43.Mn Adsorption kinetics

Study on the resistive switching time of TiO2 thin films

Byung Joon Choi, Seol Choi, Kyung Min Kim, Yong Cheol Shin, Cheol Seong Hwang, Sung-Yeon Hwang, Sung-sil Cho, Sanghyun Park, and Suk-Kyoung Hong

Appl. Phys. Lett. 89, 012906 (2006); http://dx.doi.org/10.1063/1.2219726 (3 pages) | Cited 57 times

Online Publication Date: 7 July 2006

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The required time for voltage-pulse-induced resistive switching of 40-nm-thick TiO2 thin films integrated in a contact-type structure (Pt top and TiN bottom contact, contact area ∼ 0.07 μm2) was studied as a function of pulse voltage. For off→on switching at least 2 V was necessary and the minimum switching times were ∼ 20 ns at 2 V and ∼ 10 ns at 3 V. For on→off switching, a minimum switching time of 5 μs was obtained at 2.5 V. The resistance of the on-state device was also dependent on the switching voltage and time.
Show PACS
73.61.Ng Insulators
73.40.-c Electronic transport in interface structures
Page 2 of 4 Pages Previous Page Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close