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

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

21 Jul 2003

Volume 83, Issue 3, pp. 407-587

Issue Cover Spotlight Figure

Appl. Phys. Lett. 83, 575 (2003); http://dx.doi.org/10.1063/1.1594830 (3 pages)

P. Yu, M. Mustata, J. J. Turek, P. M. W. French, M. R. Melloch, and D. D. Nolte
Enlarge Image | Read More
Page 2 of 3 Pages Previous Page Next Page | Jump to Page
back to top
RSS Feeds

Conductivity of macromolecular networks measured by electrostatic force microscopy

C. H. Lei, A. Das, M. Elliott, and J. E. Macdonald

Appl. Phys. Lett. 83, 482 (2003); http://dx.doi.org/10.1063/1.1592888 (3 pages) | Cited 24 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
High-resolution electrostatic force microscopy (EFM)-phase measurements are reported on molecular networks of semiconductor polymer poly-hexylthiophene (P3HT) and DNA molecules. A lateral resolution of better than 20 nm is demonstrated in EFM-phase images of the P3HT network by detecting the phase shift of the tip along the molecules under electrical bias. Strands of λ-DNA are shown to be highly insulating in comparison to the semiconductor polymer P3HT, with a minimum resistance of ∼ 1×107 Ω cm. © 2003 American Institute of Physics.
Show PACS
72.80.Tm Composite materials
73.61.Ph Polymers; organic compounds
68.37.Ps Atomic force microscopy (AFM)
73.40.Cg Contact resistance, contact potential
68.35.B- Structure of clean surfaces (and surface reconstruction)

Effects of deep-level defects on ohmic contact and frequency performance of AlGaN/GaN high-electron-mobility transistors

G. H. Jessen, R. C. Fitch, J. K. Gillespie, G. D. Via, B. D. White, S. T. Bradley, D. E. Walker, and L. J. Brillson

Appl. Phys. Lett. 83, 485 (2003); http://dx.doi.org/10.1063/1.1593829 (3 pages) | Cited 6 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have characterized AlGaN/GaN high-electron-mobility-transistors on sapphire and silicon carbide substrates with electrical and microcathodoluminescence spectral measurements. Quarter wafer-scale comparisons of spectral features in the GaN attributed to donor–acceptor pair (DAP) transitions and yellow luminescence (YL) from deep acceptors show that the specific contact resistance is related to the ratio of the DAP to YL defect emission intensities. This suggests that these defects interact to change the contact resistance locally on the GaN side of the AlGaN/GaN interface. We show that changes in the frequency response of these transistors can be attributed to these defects at the interface. © 2003 American Institute of Physics.
Show PACS
85.30.Tv Field effect devices
71.55.Eq III-V semiconductors
73.40.Cg Contact resistance, contact potential
73.20.Hb Impurity and defect levels; energy states of adsorbed species
78.66.Fd III-V semiconductors
78.60.Hk Cathodoluminescence, ionoluminescence
73.40.Ns Metal-nonmetal contacts

Tunneling transport in polyoxometalate based composite materials

N. Glezos, P. Argitis, D. Velessiotis, and C. D. Diakoumakos

Appl. Phys. Lett. 83, 488 (2003); http://dx.doi.org/10.1063/1.1594278 (3 pages) | Cited 18 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Molecular materials containing tungsten polyoxometalates as the active elements embedded into polymer matrices are investigated as candidates for electronic device applications. The transport properties of these materials are investigated varying the interelectrode spacing and the polyoxometalate concentration. The I–V characteristics of planar devices reveal a conductivity peak at room temperature conditions for intermolecular distances less than 3 nm and electrode distances less than 100 nm. The transport characteristics are discussed in terms of tunneling mechanisms. © 2003 American Institute of Physics.
Show PACS
72.80.Tm Composite materials
72.20.Fr Low-field transport and mobility; piezoresistance

Room-temperature electrical conductivity studies of sulfur-modified microcrystalline diamond thin films

S. Gupta, B. R. Weiner, and G. Morell

Appl. Phys. Lett. 83, 491 (2003); http://dx.doi.org/10.1063/1.1591065 (3 pages) | Cited 15 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The room-temperature electrical conductivity of sulfur-incorporated microcrystalline diamond (μc-D:S) thin films synthesized by hot-filament chemical vapor deposition was investigated as a function of sulfur concentration. The films were prepared using a 0.3% CH4/H2 gas mixture and hydrogen sulfide (H2S) as dopant source on intrinsic Si(001) substrates. The μc-D:S films exhibited an increase in n-type conductivity with increase in H2S concentration from 0 to 200 ppm, followed by a decrease in conductivity and sign reversal for the films grown with 500 ppm of H2S. These films were also characterized using scanning electron microscopy, atomic force microscopy, and Raman spectroscopy techniques. The findings are discussed in terms of the role of sulfur in the films. The films grown at the highest [H2S] possess the highest carrier concentration ( ∼ 1.07×1017/cm3) and the lowest carrier Hall mobility (0.01 cm2 V−1 s−1). Since the conductivity is affected by carrier concentration and crystallinity, the relatively low experimental conductivity values are connected to low mobilities arising from crystal defects and grain boundaries induced by sulfur addition, and to low carrier concentrations due to incomplete ionization of S atoms. © 2003 American Institute of Physics.
Show PACS
73.61.Cw Elemental semiconductors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
61.72.up Other materials
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
73.50.Dn Low-field transport and mobility; piezoresistance
81.05.U- Carbon/carbon-based materials
81.05.Cy Elemental semiconductors

Boron pile-up at the interface between plasma enhanced chemical vapor deposited TiSi2 film and BF2-doped Si

Yoon-Jik Lee, Hyun Chul Sohn, and Sung-Woong Chung

Appl. Phys. Lett. 83, 494 (2003); http://dx.doi.org/10.1063/1.1594287 (3 pages) | Cited 1 time

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have investigated the redistribution of boron in BF2-doped Si substrate during plasma enhanced chemical vapor deposition (PECVD) of TiSi2 with secondary ion mass spectrometry. Boron concentration was observed to be increased at the TiSi2/Si interface after deposition of PECVD TiSi2. Contact resistance with PECVD TiSi2 was measured to be constant in the range of −30–125 °C, implying that the accumulated boron was electrically active and charge transport was field emission in nature. © 2003 American Institute of Physics.
Show PACS
61.72.S- Impurities in crystals
73.40.Cg Contact resistance, contact potential
68.35.Ct Interface structure and roughness
81.05.Cy Elemental semiconductors
71.55.Cn Elemental semiconductors
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
52.77.Dq Plasma-based ion implantation and deposition
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

NiAi1.74Al0.26 and NiSi1.83Ga0.17: Two materials with perfect lattice match to Si

Klaus W. Richter and Kurt Hiebl

Appl. Phys. Lett. 83, 497 (2003); http://dx.doi.org/10.1063/1.1594289 (3 pages) | Cited 7 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the preparation and characterization of two materials based on cubic NiSi2 (CaF2-type, cF12, Fmmathm) that show no lattice mismatch to Si and are thus promising materials for perfect epitaxial films grown on silicon. The perfectly lattice-matched materials are special compositions within the extended solid solution phases NiSi2−xAlx and NiSi2−xGax with x = 0.26 for Al and x = 0.17 for Ga, respectively. The variations of bulk lattice parameters with the composition were studied by means of x-ray diffraction and the melting behavior of the solid solution phases was investigated by differential thermal analysis. Both phases are thermally stable up to temperatures around 1000 °C. Phase diagram investigations show that the respective phases are in thermodynamic equilibrium with pure silicon. The electrical conductivity of NiSi2−xAlx and NiSi2−xGax was studied on selected bulk samples between 4.2 and 300 K. Both materials show metallic behavior with specific room-temperature resistivities between 23 and 40 μΩ cm. The difference is mainly due to intrinsic defects in these compounds. © 2003 American Institute of Physics.
Show PACS
61.66.Dk Alloys
81.10.Fq Growth from melts; zone melting and refining
81.05.Bx Metals, semimetals, and alloys
81.30.Bx Phase diagrams of metals, alloys, and oxides
64.70.D- Solid-liquid transitions
72.15.Eb Electrical and thermal conduction in crystalline metals and alloys

Direct and inverse photoemission spectroscopy studies of potassium intercalated films of two organic semiconductors

T. Schwieger, M. Knupfer, W. Gao, and A. Kahn

Appl. Phys. Lett. 83, 500 (2003); http://dx.doi.org/10.1063/1.1595151 (3 pages) | Cited 20 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A combined direct and inverse photoemission spectroscopy study of the occupied and unoccupied states of the organic semiconductors ZnPc and α-[N,N′-diphenyl-N,N′-bis(1-naphthyl)-1, 1′-biphenyl-4,4″ diamine] in the pristine and reduced state is presented. The splitting of the lowest unoccupied molecular orbital observed upon potassium intercalation leads to an evaluation of the size of correlation effects in both molecular systems. As expected, the Fermi level is found to shift towards the vacuum level upon intercalation. However, the results clearly demonstrate that the Fermi level in potassium intercalated organic semiconductors cannot a priori be assumed to be pinned at the onset of the lowest unoccupied molecular orbital in all cases. © 2003 American Institute of Physics.
Show PACS
71.20.Rv Polymers and organic compounds
79.60.Fr Polymers; organic compounds
78.70.-g Interactions of particles and radiation with matter
71.45.Gm Exchange, correlation, dielectric and magnetic response functions, plasmons
71.20.Tx Fullerenes and related materials; intercalation compounds

Electrical noise in n- and p-type Ag2Te

L. Jiang and E. R. Nowak

Appl. Phys. Lett. 83, 503 (2003); http://dx.doi.org/10.1063/1.1593820 (3 pages) | Cited 1 time

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The relatively large and linear magnetoresistance found in nonstoichiometric silver chalcogenides makes them attractive candidates for field sensing applications. We report on the intrinsic electrical noise in bulk, polycrystalline Ag2+δTe. Low-frequency noise is due to resistance fluctuations having a 1/f-like power spectrum. The temperature dependence of the noise magnitude and its spectral slope indicate thermally activated kinetics that we attribute to some form of charge trapping–detrapping process occurring in or near the intergranular regions. The effective magnetic field noise in Ag2+δTe is compared to other materials systems used in field sensing applications. © 2003 American Institute of Physics.
Show PACS
72.80.Ga Transition-metal compounds
72.70.+m Noise processes and phenomena
72.20.My Galvanomagnetic and other magnetotransport effects
back to top
RSS Feeds

Vortex melting line and anisotropy of high-pressure-synthesized TlBa2Ca2Cu3O10−y high-temperature superconductor from third-harmonic susceptibility studies

A. Crisan, A. Iyo, and Y. Tanaka

Appl. Phys. Lett. 83, 506 (2003); http://dx.doi.org/10.1063/1.1593824 (3 pages) | Cited 13 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The fundamental and third-harmonic susceptibility response of YBa2Cu3O7−δ (YBCO) and TlBa2Ca2Cu3O10−y (Tl:1223) high-critical temperature (Tc) superconductors with preferentially oriented crystallites has been measured in various magnetic fields up to 14 T, and with very low ac field amplitude, to probe the melting transition of the vortex matter. This method does not require large single crystals, being therefore suitable for high-Tc superconductors with small crystallites, prepared with high-pressure synthesis techniques. We determine experimentally the melting line of vortices and the anisotropy factor in high-pressure-grown Tl:1223 with a high Tc of 133.5 K. Results from similar measurements on YBCO with preferentially oriented grains are consistent with both commonly accepted models of the melting line and values of the anisotropy factor, supporting the validity of our approach. © 2003 American Institute of Physics.
Show PACS
74.25.Uv Vortex phases (includes vortex lattices, vortex liquids, and vortex glasses)
74.72.-h Cuprate superconductors
74.25.Ha Magnetic properties including vortex structures and related phenomena
81.05.Je Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides)

Switching a spin valve back and forth by current-induced domain wall motion

J. Grollier, P. Boulenc, V. Cros, A. Hamzić, A. Vaurès, A. Fert, and G. Faini

Appl. Phys. Lett. 83, 509 (2003); http://dx.doi.org/10.1063/1.1594841 (3 pages) | Cited 183 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have studied the current-induced displacement of a domain wall (DW) in the permalloy (Py) layer of a Co/Cu/Py spin valve structure at zero and very small applied field. The displacement is in opposite direction for opposite dc currents, and the current density required to move DW is only of the order of 106 A/cm2. For H = 3 Oe, a back and forth DW motion between two stable positions is observed. We also discuss the effect of an applied field on the DW motion. © 2003 American Institute of Physics.
Show PACS
75.47.Np Metals and alloys
75.70.Kw Domain structure (including magnetic bubbles and vortices)
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)

Superconducting properties of polycrystalline Nb nanowires templated by carbon nanotubes

A. Rogachev and A. Bezryadin

Appl. Phys. Lett. 83, 512 (2003); http://dx.doi.org/10.1063/1.1592313 (3 pages) | Cited 49 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Continuous Nb wires, 7–15 nm in diameter, have been fabricated by sputter-coating single fluorinated carbon nanotubes. Transmission electron microscopy revealed that the wires are polycrystalline, having grain sizes of about 5 nm. The critical current of wires thicker than ∼12 nm is very high (107 A/cm2) and comparable to the expected depairing current. The resistance versus temperature curves measured down to 0.3 K are well described by the Langer–Ambegaokar–McCumber–Halperin theory of thermally activated phase slips. Quantum phase slips are suppressed. © 2003 American Institute of Physics.
Show PACS
74.70.Ad Metals; alloys and binary compounds (including A15, MgB2, etc.)
74.25.Sv Critical currents

Simple enhancement of the magnetocaloric effect in giant magnetocaloric materials

L. H. Lewis, M. H. Yu, and R. J. Gambino

Appl. Phys. Lett. 83, 515 (2003); http://dx.doi.org/10.1063/1.1593821 (3 pages) | Cited 10 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A simple method of enhancing the magnetocaloric effect (MCE)) in ferromagnetic materials is described. Thin layers of pure Fe of 0.1- and 0.2-μm thickness were evaporated onto both sides of polished 0.6-mm, slices of the giant magnetocaloric material Gd5Si1.5Ge2.5. The slices were stacked for magnetic measurement in the temperature range from 165 to 235 K to assess the MCE. Sample geometries with the iron layers oriented both parallel and perpendicular to the applied field were measured. In the metamagnetic transition temperature range, the Fe layer in the parallel geometry lowers the onset field of the metamagnetic transition by 4240 Oe for the 0.1-μm layer thickness and by 4940 Oe for the 0.2-μm layer thickness from the base value of 8700 Oe at 187 K in the absence of Fe layers. Furthermore, the 0.1-μm layer of Fe oriented perpendicular to the applied field is found to enhance the entropy change, and thus the magnetocaloric effect, by approximately 11% above its base value at 191.5 K; intriguingly, the 0.2-μm Fe layer does not obviously alter the MCE from its base value. © 2003 American Institute of Physics.
Show PACS
75.30.Sg Magnetocaloric effect, magnetic cooling
75.50.Cc Other ferromagnetic metals and alloys
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)
75.40.Cx Static properties (order parameter, static susceptibility, heat capacities, critical exponents, etc.)
75.50.Bb Fe and its alloys
75.70.Ak Magnetic properties of monolayers and thin films

Extraordinary Hall effect and ferromagnetism in Fe-doped reduced rutile

Zhenjun Wang, Wendong Wang, Jinke Tang, Le Duc Tung, Leonard Spinu, and Weilie Zhou

Appl. Phys. Lett. 83, 518 (2003); http://dx.doi.org/10.1063/1.1593825 (3 pages) | Cited 68 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Room-temperature ferromagnetism is observed in reduced rutile TiO2−δ by Fe doping. The epitaxial films grown by pulsed-laser deposition are carefully examined by x-ray diffraction, transmission electron microscopy, and magnetic and transport measurements. The films exhibit the extraordinary Hall-effect and thin-film magnetic shape anisotropy. The magnetic moments and anticipated Curie temperatures of the films rule out Fe particles, iron oxides, and Ti–Fe oxides as possible sources for the observed magnetic signals. The carriers of the Fe-doped reduced rutile are p-type, with a carrier density of 1×1022/cm3. This room-temperature dilute magnetic semiconductor should find potential applications in spintronics. © 2003 American Institute of Physics.
Show PACS
75.70.Ak Magnetic properties of monolayers and thin films
73.61.Le Other inorganic semiconductors
75.50.Pp Magnetic semiconductors
75.50.Dd Nonmetallic ferromagnetic materials
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
75.30.Gw Magnetic anisotropy
68.55.-a Thin film structure and morphology
68.37.Lp Transmission electron microscopy (TEM)
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)
75.40.-s Critical-point effects, specific heats, short-range order
75.30.Cr Saturation moments and magnetic susceptibilities
72.25.-b Spin polarized transport
75.47.Pq Other materials
85.75.-d Magnetoelectronics; spintronics: devices exploiting spin polarized transport or integrated magnetic fields

Molecular-beam epitaxy of the half-Heusler alloy NiMnSb on (In,Ga)As/InP (001)

P. Bach, A. S. Bader, C. Rüster, C. Gould, C. R. Becker, G. Schmidt, L. W. Molenkamp, W. Weigand, C. Kumpf, E. Umbach, R. Urban, G. Woltersdorf, and B. Heinrich

Appl. Phys. Lett. 83, 521 (2003); http://dx.doi.org/10.1063/1.1594286 (3 pages) | Cited 23 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the growth of the half-Heusler alloy NiMnSb on InP (001) by molecular-beam epitaxy using a lattice-matched (In,Ga)As buffer. High-resolution x-ray diffraction confirms a high crystalline quality. Spot-profile analysis low-energy electron diffraction measurements show well-defined surface reconstructions. The samples show the expected high Curie temperature and an uniaxial anisotropy. © 2003 American Institute of Physics.
Show PACS
81.05.Bx Metals, semimetals, and alloys
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
75.70.Ak Magnetic properties of monolayers and thin films
75.30.Gw Magnetic anisotropy
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)
68.35.B- Structure of clean surfaces (and surface reconstruction)
68.49.Jk Electron scattering from surfaces
68.55.-a Thin film structure and morphology
68.49.Uv X-ray standing waves
back to top
RSS Feeds

Investigation of electrical conduction in carbon-doped silicon oxide using a voltage ramp method

K. Y. Yiang, W. J. Yoo, Q. Guo, and Ahila Krishnamoorthy

Appl. Phys. Lett. 83, 524 (2003); http://dx.doi.org/10.1063/1.1592618 (3 pages) | Cited 14 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Electrical conduction in carbon-doped silicon oxide (SiOC) is investigated over the electric field range of 0 MV/cm to the breakdown field at 300 K. Below 1.4 MV/cm, the dominant conduction mechanisms are electron hopping (<0.2 MV/cm) and Schottky emission (0.2 to 1.4 MV/cm). Poole–Frenkel emission at higher fields (>1.4 MV/cm) confirms the presence and role of electron traps in the conduction of SiOC. Near breakdown field (1.7 to 2.08 MV/cm), Fowler–Nordheim tunneling occurs and this is the major cause of dielectric breakdown in SiOC. The effective dielectric constant of SiOC in an integrated Cu damascene structure is derived from both experimental data and emission modeling. © 2003 American Institute of Physics.
Show PACS
73.61.Ng Insulators
77.55.-g Dielectric thin films
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
85.40.Ls Metallization, contacts, interconnects; device isolation
77.22.Jp Dielectric breakdown and space-charge effects
73.43.Jn Tunneling
73.50.Fq High-field and nonlinear effects
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths
77.22.Ch Permittivity (dielectric function)

Monodomain versus polydomain piezoelectric response of 0.67Pb(Mg1/3Nb2/3)O3–0.33PbTiO3 single crystals along nonpolar directions

Dragan Damjanovic, Marko Budimir, Matthew Davis, and Nava Setter

Appl. Phys. Lett. 83, 527 (2003); http://dx.doi.org/10.1063/1.1592880 (3 pages) | Cited 47 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF


See Also: Erratum

Show Abstract
Using recently published experimental data we calculated the piezoelectric response of rhombohedral 0.67Pb(Mg1/3Nb2/3)O3–0.33PbTiO3 monodomain single crystals along arbitrary directions. The calculations indicate that the value of the longitudinal piezoelectric coefficient along the [001] axis of the pseudocubic system ([111] axis of the rhombohedral system) of a monodomain crystal is close to the value determined experimentally along the same direction of a multidomain crystal with a so-called “engineered domain state.” The results thus show that the large piezoelectric response in this material is dominated by intrinsic crystal lattice effects and that the multidomain state has a relatively minor effect (<20%). In addition, calculations predict a transverse piezoelectric coefficient >1900 pC/N for certain directions of the monodomain crystal. © 2003 American Institute of Physics.
Show PACS
77.65.Bn Piezoelectric and electrostrictive constants
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.80.Dj Domain structure; hysteresis

Linear relationship between H+-trapping reaction energy and defect generation: Insight into nitrogen-enhanced negative bias temperature instability

Shyue Seng Tan, T. P. Chen, Jia Mei Soon, Kian Ping Loh, C. H. Ang, W. Y. Teo, and L. Chan

Appl. Phys. Lett. 83, 530 (2003); http://dx.doi.org/10.1063/1.1593211 (3 pages) | Cited 10 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this letter, we report a first-principles calculation which is well correlated to experiment on the role of nitrogen at Si/SiOxNy interface in negative bias temperature instability (NBTI). Our calculation shows that nitrogen’s lone pair electrons can trap dissociated hydrogen species more easily than oxygen. After trapping, a positive charge complex is formed and weakening of bond strength is observed at trapping site. Furthermore, as nitrogen concentration goes beyond 8 at. %, the neighboring effect from nitrogen starts to play a role in further degradation. The interfacial nitrogen dependence of the NBTI-induced defect generation is found to coincide with that of the H+-trapping reaction energy. Eventually, a linear correlation is found between the reaction energy and the defect generation. This provides an insight into nitrogen-enhanced NBTI. © 2003 American Institute of Physics.
Show PACS
73.20.Hb Impurity and defect levels; energy states of adsorbed species
71.15.Nc Total energy and cohesive energy calculations
68.35.Ct Interface structure and roughness
73.20.At Surface states, band structure, electron density of states

Passivation and interface state density of SiO2/HfO2-based/polycrystalline-Si gate stacks

R. J. Carter, E. Cartier, A. Kerber, L. Pantisano, T. Schram, S. De Gendt, and M. Heyns

Appl. Phys. Lett. 83, 533 (2003); http://dx.doi.org/10.1063/1.1592639 (3 pages) | Cited 57 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate that a forming gas annealing temperature of 520 °C significantly improves interface state passivation for SiO2/HfO2-based/polycrystalline-Si gate stacks as compared to annealing at 420 °C normally used for SiO2/polycrystalline-Si gate stacks. We also show that the initial interface state density is dependent upon the interfacial SiO2 preparation, whereby a chemically grown oxide has a higher initial interface state density as compared to a thermally grown oxide. © 2003 American Institute of Physics.
Show PACS
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
81.65.Rv Passivation
73.20.-r Electron states at surfaces and interfaces
61.72.Cc Kinetics of defect formation and annealing

Scaling behavior of ferroelectric hysteresis loop in pulsed-laser-deposited SrBi2Ta2O9 thin film

Jong-Ho Park, Chung-Sik Kim, Byung-Chun Choi, Byung Kee Moon, Jung Hyun Jeong, and Ill Won Kim

Appl. Phys. Lett. 83, 536 (2003); http://dx.doi.org/10.1063/1.1591997 (3 pages) | Cited 19 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Ferroelectric SrBi2Ta2O9 thin films were grown on a highly oriented Pt/Ti/SiO2/Si substrates using pulsed laser ablation. The hysteresis loop of ferroelectric SrBi2Ta2O9 was studied as a function of applied field amplitude. A scaling analysis of ferroelectric hysteresis loop area showed A∝Eα. The value of scaling exponent, α = 0.40, is not similar to the reported theoretical and experimental values. This result shows the possibility that both ferroelectric bulk and thin-film systems may have different universal behaviors. Influence of potential in the surface of SrBi2Ta2O9 thin film was measured in the dc applied field range from 0 to 8 V by using electro force microscopy. Roughness of surface potential of SrBi2Ta2O9 thin film changed rapidly around the coercive voltage, Vc ∼ 1.5 V. It is believed that the switching effect of SrBi2Ta2O9 thin film includes surface polarization at the surface of the thin film as well as pure spontaneous polarization in the bulk. © 2003 American Institute of Physics.
Show PACS
77.55.-g Dielectric thin films
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.80.Dj Domain structure; hysteresis
81.15.Fg Pulsed laser ablation deposition
77.80.-e Ferroelectricity and antiferroelectricity
77.22.Ej Polarization and depolarization
back to top
RSS Feeds

Characteristics and field emission of conducting poly (3,4-ethylenedioxythiophene) nanowires

B. H. Kim, M. S. Kim, K. T. Park, J. K. Lee, D. H. Park, J. Joo, S. G. Yu, and S. H. Lee

Appl. Phys. Lett. 83, 539 (2003); http://dx.doi.org/10.1063/1.1592004 (3 pages) | Cited 53 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Conducting poly (3,4-ethylenedioxythiophene) nanowires were synthesized by using an electrochemical polymerization method with a nanoporous template. Scanning and transmission electron microscopy confirmed the formation of conducting polymer nanowires (CPNWs) with an open end. The formation and the electrical properties of the CPNWs formed were dependent on synthetic conditions, such as the doping level, the polymerization time, and the applied current. The measured electrical conductivity of a single strand of CPNW was ∼ 3.4×10−3 S/cm at room temperature. From the ultraviolet and visible absorbance spectra, we observed a π–π∗ transition at ∼ 2.1 eV for the de-doped systems. A field emission cell of CPNW nanotips was fabricated. The turn-on field of the CPNWs was 3.5 ∼ 4 V/μm at 10 μA/cm2, and the current density increased up to 100 μA/cm2 at ∼ 4.5 V/μm. The field enhancement factor of CPNW nanotips was ∼ 1200, which is comparable to those of carbon nanotubes. © 2003 American Institute of Physics.
Show PACS
72.80.Le Polymers; organic compounds (including organic semiconductors)
79.70.+q Field emission, ionization, evaporation, and desorption
73.63.Nm Quantum wires
78.40.Me Organic compounds and polymers
82.45.Wx Polymers and organic materials in electrochemistry
82.35.-x Polymers: properties; reactions; polymerization
82.45.Yz Nanostructured materials in electrochemistry

Density functional theory study of HfCl4, ZrCl4, and Al(CH3)3 decomposition on hydroxylated SiO2: Initial stage of high-k atomic layer deposition

L. Jeloaica, A. Estève, M. Djafari Rouhani, and D. Estève

Appl. Phys. Lett. 83, 542 (2003); http://dx.doi.org/10.1063/1.1587261 (3 pages) | Cited 20 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The initial stage of atomic layer deposition of HfO2, ZrO2, and Al2O3 high-k films, i.e., the decomposition of HfCl4, ZrCl4, and Al(CH3)3 precursor molecules on an OH-terminated SiO2 surface, is investigated within density functional theory. The energy barriers are determined using artificial activation of vibrational normal modes. For all precursors, reaction proceeds through the formation of intermediate complexes that have equivalent formation energies (∼−0.45 eV), and results in HCl and CH4 formation with activation energies of 0.88, 0.91, and 1.04 eV for Hf, Zr, and Al based precursors, respectively. The reaction product of Al(CH3)3 decomposition is found to be more stable (by −1.45 eV) than the chemisorbed intermediate complex compared to the endothermic decomposition of HfCl4 and ZrCl4 chemisorbed precursors (0.26 and 0.29 eV, respectively). © 2003 American Institute of Physics.
Show PACS
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
82.33.Ya Chemistry of MOCVD and other vapor deposition methods
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
71.15.Mb Density functional theory, local density approximation, gradient and other corrections
77.55.-g Dielectric thin films
68.55.A- Nucleation and growth
82.30.Lp Decomposition reactions (pyrolysis, dissociation, and fragmentation)
82.60.Cx Enthalpies of combustion, reaction, and formation
68.43.Bc Ab initio calculations of adsorbate structure and reactions
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces

Competing influence of damage buildup and lattice vibrations on ion range profiles in Si

M. Posselt, M. Mäder, R. Grötzschel, and M. Behar

Appl. Phys. Lett. 83, 545 (2003); http://dx.doi.org/10.1063/1.1594281 (3 pages) | Cited 4 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Phosphorus depth profiles in Si obtained by 140 keV implantation in the [001] axial channel direction and in a direction 7° off axis are investigated at two different doses (5×1013 and 5×1015 cm−2) for implantation temperatures of 350 °C and room temperature (RT). At low dose and at channeling incidence, the penetration depth of implanted ions is higher at RT than at 350 °C. This behavior is caused by the dechanneling of lattice vibrations. At high dose, the temperature dependence of the shape of the implantation profile is opposite that at low dose, due to enhanced dechanneling by defect accumulation at RT. On the other hand, damage buildup does not occur at elevated temperature. The temperature dependence of the profiles obtained by tilted implantation is much less than for the channeled implants. The P profiles measured can be reproduced very well by atomistic simulations which take into account both lattice vibrations and defect accumulation during ion bombardment. © 2003 American Institute of Physics.
Show PACS
61.85.+p Channeling phenomena (blocking, energy loss, etc.)
61.72.uf Ge and Si
61.80.Jh Ion radiation effects
61.82.Fk Semiconductors
63.20.-e Phonons in crystal lattices
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces

Characteristics of plasma processed SiC nanocrystallites and nanorods

S. B. Qadri, M. A. Imam, C. R. Feng, B. B. Rath, M. Yousuf, and S. K. Singh

Appl. Phys. Lett. 83, 548 (2003); http://dx.doi.org/10.1063/1.1594831 (3 pages) | Cited 11 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Nanoparticles and nanorods of SiC were synthesized using arc-plasma processing of coarse particles. X-ray diffraction and Raman spectroscopic studies showed the presence of β-SiC and carbon nanotubes in the starting coarse particles and SiC nanorods in the ultrafine particles produced by plasma processing. Scanning electron microscopy and transmission electron microscopy confirmed the presence of carbon nanotubes in the starting material and nanorods of SiC in the plasma-processed samples. © 2003 American Institute of Physics.
Show PACS
81.07.Bc Nanocrystalline materials
61.46.-w Structure of nanoscale materials
52.77.Dq Plasma-based ion implantation and deposition
81.07.Wx Nanopowders
81.16.-c Methods of micro- and nanofabrication and processing
81.07.De Nanotubes
78.30.Hv Other nonmetallic inorganics
78.67.Bf Nanocrystals, nanoparticles, and nanoclusters
68.37.Lp Transmission electron microscopy (TEM)
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)

Nanoring formation by direct-write inorganic electron-beam lithography

N. Jiang, G. G. Hembree, J. C. H. Spence, J. Qiu, F. J. Garcia de Abajo, and J. Silcox

Appl. Phys. Lett. 83, 551 (2003); http://dx.doi.org/10.1063/1.1592895 (3 pages) | Cited 17 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A direct-write inorganic lithography technique is described which is capable of forming nanoscale rings of amorphous metals and semiconductors in glasses. Near-edge electron energy loss spectroscopy and electron diffraction using a subnanometer probe are used to analyze the composition and formation mechanism of these nanorings. The optical absorption cross section of one ring is calculated by multiple scattering methods. Applications in quantum electronics and the design of media with dielectric properties are suggested. © 2003 American Institute of Physics.
Show PACS
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
81.16.Nd Micro- and nanolithography
79.20.Uv Electron energy loss spectroscopy
78.67.Bf Nanocrystals, nanoparticles, and nanoclusters
78.40.-q Absorption and reflection spectra: visible and ultraviolet

Optical recording in silver-doped glasses by a femtosecond laser

Yu. Kaganovskii, I. Antonov, D. Ianetz, M. Rosenbluh, J. Ihlemann, S. Mueller, G. Marowsky, and A. A. Lipovskii

Appl. Phys. Lett. 83, 554 (2003); http://dx.doi.org/10.1063/1.1593828 (3 pages) | Cited 2 times

Online Publication Date: 16 July 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Glass embedded with silver nanoclusters has been used to record interference patterns of two 500-fs, 496-nm, laser pulses. The recording is based on optical heating of metal clusters and their subsequent motion in temperature gradients. Estimates of the kinetics of cluster motion and growth are in good agreement with experiments. © 2003 American Institute of Physics.
Show PACS
42.70.Ln Holographic recording materials; optical storage media
42.40.Ht Hologram recording and readout methods
42.70.Ce Glasses, quartz
42.40.Eq Holographic optical elements; holographic gratings
78.67.Bf Nanocrystals, nanoparticles, and nanoclusters
66.30.Xj Thermal diffusivity
Page 2 of 3 Pages Previous Page Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close