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

15 Apr 2002

Volume 80, Issue 15, pp. 2625-2806

Page 1 of 3 Pages Next Page | Jump to Page
back to top
RSS Feeds

Local fluorescent probes for the fluorescence resonance energy transfer scanning near-field optical microscopy

G. T. Shubeita, S. K. Sekatskii, G. Dietler, and V. S. Letokhov

Appl. Phys. Lett. 80, 2625 (2002); http://dx.doi.org/10.1063/1.1467695 (3 pages) | Cited 7 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present fluorescence resonance energy transfer (FRET) images of donor dye molecule clusters recorded using a local fluorescence probe for scanning near-field optical microscopy (SNOM): standard apertured SNOM fiber tip coated with the 30–100-nm-thick polymer layer stained with the acceptor dye molecules. The tip works as a “self-sharpening pencil”: the apical layers of the FRET-active tip coating are mechanically worn out during scanning thus continuously exposing a fresh active apex to continue imaging. Only a few tens of acceptor molecules are used to form the optical images, and using such an approach spatial resolution better than the size of the aperture is achievable. © 2002 American Institute of Physics.
Show PACS
07.79.Fc Near-field scanning optical microscopes
33.50.Dq Fluorescence and phosphorescence spectra

Organic light-emitting diodes with improved hole-electron balance by using copper phthalocyanine/aromatic diamine multiple quantum wells

Yong Qiu, Yudi Gao, Peng Wei, and Liduo Wang

Appl. Phys. Lett. 80, 2628 (2002); http://dx.doi.org/10.1063/1.1468894 (3 pages) | Cited 45 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Organic light-emitting diodes (OLEDs) with multiple-quantum-well structures, which consist of copper phthalocyanine and N,N′-bis-(1-naphthyl)-N,N′-diphenyl-1,1′ biphenyl 4, 4′-diamine, have been fabricated. The effect of the MQW structure upon the performance of OLEDs with tris(8-hydroxyquinoline) aluminum as the emitting material has been investigated. Compared with the luminous efficiency of the conventional diode with the MQW number of 0, that of the diode with the MQW number of 4 has been sharply increased up to 10.8 cd/A. Such an improvement in the device performance was attributed to the improved hole-electron balance, which can be further attributed to the introduction of the MQW structure. © 2002 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
78.67.De Quantum wells

Modeling of Q-switched semiconductor lasers based on type-II quantum wells: Increasing the pulse energy and peak power

Jacob B. Khurgin, Igor Vurgaftman, and Jerry R. Meyer

Appl. Phys. Lett. 80, 2631 (2002); http://dx.doi.org/10.1063/1.1468920 (3 pages) | Cited 1 time

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We propose a semiconductor laser (λ ≈ 1.25 μm) whose active region is a type-II multiple-quantum-well structure (AlGaInAs/AlGaAsSb/AlInAs on InP) to lengthen the free-carrier lifetime. Simulations project an order-of-magnitude enhancement of the Q-switched energy per pulse without increasing the pump current. © 2002 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
42.55.Rz Doped-insulator lasers and other solid state lasers
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation

Terahertz pulse propagation in a plastic photonic crystal fiber

H. Han, H. Park, M. Cho, and J. Kim

Appl. Phys. Lett. 80, 2634 (2002); http://dx.doi.org/10.1063/1.1468897 (3 pages) | Cited 108 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Guided-wave single-mode propagation of subpicosecond terahertz (THz) pulses in a plastic photonic crystal fiber has been experimentally demonstrated. The plastic photonic crystal fiber is fabricated from high-density polyethylene tubes and filaments. The fabricated fiber exhibits the low loss and relatively low dispersive propagation of THz pulses within the experimental bandwidth of 0.1–3 THz. © 2002 American Institute of Physics.
Show PACS
42.81.Dp Propagation, scattering, and losses; solitons
42.70.Jk Polymers and organics
81.05.Lg Polymers and plastics; rubber; synthetic and natural fibers; organometallic and organic materials
42.50.-p Quantum optics
42.70.Qs Photonic bandgap materials

Retrieval of the dielectric function of thin films from femtosecond pump-probe experiments

J. Jasapara, M. Mero, and W. Rudolph

Appl. Phys. Lett. 80, 2637 (2002); http://dx.doi.org/10.1063/1.1468893 (3 pages) | Cited 4 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The retrieval of the complex dielectric function from time-resolved pump-probe reflection and transmission experiments on thin films is investigated. A general approach is presented that takes into account interference effects of both the pump and the probe pulse. The influence of the pulse duration is investigated. The retrieval technique is exemplified with experimental data from a Ta2O5 film. © 2002 American Institute of Physics.
Show PACS
78.47.-p Spectroscopy of solid state dynamics
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
78.66.-w Optical properties of specific thin films
77.22.Ch Permittivity (dielectric function)

Lowering of operational voltage of organic electroluminescent devices by coating indium-tin-oxide electrodes with a thin CuOx layer

Wenping Hu, Kaoru Manabe, Takumi Furukawa, and Michio Matsumura

Appl. Phys. Lett. 80, 2640 (2002); http://dx.doi.org/10.1063/1.1469697 (2 pages) | Cited 27 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We devised a method of modifying indium-tin-oxide (ITO) electrodes for organic electroluminescent devices. It consists of deposition of a nanometer-thick Cu layer on the ITO electrode and an oxygen plasma treatment. By this modification, the surface of the ITO substrate is covered with a partly oxidized Cu layer (CuOx). The CuOx-coated ITO electrode possesses strong hole-injection ability, which leads to lowered operational voltage and high luminance from the devices consisting of tris(8-quinolinato)aluminum and diamine hole-transport layers. The hole-injection ability of the CuOx-coated ITO electrode is better than that of the ITO electrode modified by conventional methods, such as insertion of a Cu-phthalocyanine buffer layer. Moreover, the CuOx layer is effective to improve the durability of the devices. © 2002 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices
81.65.Mq Oxidation
73.61.Le Other inorganic semiconductors
78.66.Qn Polymers; organic compounds
78.60.Fi Electroluminescence
73.61.Ph Polymers; organic compounds

Optical and luminescence properties of Sm3+-doped cadmium–aluminum–silicate glasses

H. Lin, E. Y. B. Pun, L. H. Huang, and X. R. Liu

Appl. Phys. Lett. 80, 2642 (2002); http://dx.doi.org/10.1063/1.1468919 (3 pages) | Cited 21 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Sm3+-doped cadmium–aluminum–silicate glasses (CdO–Al2O3–SiO2) have been fabricated and characterized optically. Intense visible lights and near-infrared emissions were observed under ultraviolet light and 488 nm laser excitation. The density, refractive index, optical absorption, Judd–Ofelt parameters, and spontaneous transition probabilities have been measured and calculated. Intense fluorescences at 1.2 and 1.29 μm wavelengths were observed, indicating that the glasses are promising materials for laser and optical amplifier applications operating in the 1.2–1.3 μm low-loss window of telecommunication fiber. © 2002 American Institute of Physics.
Show PACS
42.70.Ce Glasses, quartz
78.55.Hx Other solid inorganic materials
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
78.40.Pg Disordered solids

High-efficiency green phosphorescence from spin-coated single-layer dendrimer light-emitting diodes

J. P. J. Markham, S.-C. Lo, S. W. Magennis, P. L. Burn, and I. D. W. Samuel

Appl. Phys. Lett. 80, 2645 (2002); http://dx.doi.org/10.1063/1.1469218 (3 pages) | Cited 89 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate very high-efficiency green phosphorescence from a single-layer dendrimer organic light-emitting diode formed by spin-coating. A first generation fac-tris(2-phenylpyridine) iridium cored dendrimer doped into a wide-gap 4,4′-bis(N-carbazole) biphenyl host displays a peak external quantum efficiency of 8.1% (28 Cd/A) at a brightness of 3450 Cd/m2 and a current density of 13.1 mA/cm2. A peak power efficiency of 6.9 lm/W was measured at 1475 Cd/m2 and 5 mA/cm2. We attribute this exceptionally high quantum efficiency for a single-layer device to the excellent film forming properties and high photoluminescence quantum yield of the dendrimer blend and efficient injection of charge into the emissive layer. These results suggest that dendrimers are an effective method for producing efficient phosphorescent devices by spin-coating. © 2002 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices
78.55.Kz Solid organic materials
81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
back to top
RSS Feeds

Thermoelectron-enhanced micrometer-scale plasma generation

Tsuyohito Ito and Kazuo Terashima

Appl. Phys. Lett. 80, 2648 (2002); http://dx.doi.org/10.1063/1.1468898 (3 pages) | Cited 38 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The use of thermoelectrons allowed easy generation of a micrometer-scale very high-frequency plasma (thermoelectron-enhanced micrometer-scale plasma) in a fine capillary, with an inner diameter of approximately 120 μm. A tungsten wire, whose diameter was 25 μm, inserted into the region was used to provide thermoelectrons. Approximately 5 W of power was sufficient to sustain this plasma. The plasma was very stable and the discharge continued for at least 60 min. © 2002 American Institute of Physics.
Show PACS
52.50.Gj Plasma heating by particle beams
52.80.Pi High-frequency and RF discharges
52.35.-g Waves, oscillations, and instabilities in plasmas and intense beams
back to top
RSS Feeds

Nanoindentation-induced deformation of Ge

J. E. Bradby, J. S. Williams, J. Wong-Leung, M. V. Swain, and P. Munroe

Appl. Phys. Lett. 80, 2651 (2002); http://dx.doi.org/10.1063/1.1469660 (3 pages) | Cited 16 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The deformation mechanisms of crystalline (100) Ge were studied using nanoindentation, cross sectional transmission electron microscopy (XTEM) and Raman microspectroscopy. For a wide range of indentation conditions using both spherical and pointed indenters, multiple discontinuities were found in the force–displacement curves on loading, but no discontinuities were found on unloading. Raman microspectroscopy, measured from samples which had plastically deformed on loading, showed a spectrum shift from that in pristine Ge, suggesting only residual strain. No evidence (such as extra Raman bands) was found to suggest that any pressure-induced phase transformations had occurred, despite the fact that the material had undergone severe plastic deformation. Selected area diffraction pattern studies of the mechanically damaged regions also confirmed the absence of additional phases. Moreover, XTEM showed that, at low loads, plastic deformation occurs by twinning and dislocation motion. This indicates that the hardness of Ge measured by indentation is not primarily dominated by phase transformation, rather by the nucleation and propagation of twin bands and/or dislocations. © 2002 American Institute of Physics.
Show PACS
62.20.F- Deformation and plasticity
62.20.M- Structural failure of materials
61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)
62.20.Qp Friction, tribology, and hardness
68.37.Lp Transmission electron microscopy (TEM)
78.30.Am Elemental semiconductors and insulators
61.72.Mm Grain and twin boundaries
61.72.Lk Linear defects: dislocations, disclinations

Studies of Mn/GaAs digital alloys using x-ray absorption fine structure and x-ray diffraction methods

Y. L. Soo, G. Kioseoglou, S. Kim, X. Chen, H. Luo, Y. H. Kao, Y. Sasaki, X. Liu, and J. K. Furdyna

Appl. Phys. Lett. 80, 2654 (2002); http://dx.doi.org/10.1063/1.1467982 (3 pages) | Cited 14 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Local structure and effective chemical valency of Mn atoms in Mn/GaAs digital alloys have been investigated using the x-ray absorption fine structure techniques. The samples were prepared by molecular-beam epitaxy with different thickness of GaAs layers separating the nominal Mn monolayers. Lattice constants of the digital alloys are found by x-ray diffraction to increase linearly in a very narrow range (about 0.3%) with the Mn/GaAs ratio in the samples. Our data show that Mn atoms in the nominal Mn monolayers actually combine with GaAs to form (Ga, Mn)As alloys with Mn atoms substituting for the Ga sites in GaAs. This result clearly rules out the possibility of dominant MnAs formation. © 2002 American Institute of Physics.
Show PACS
68.35.Ct Interface structure and roughness
68.35.Fx Diffusion; interface formation
68.35.Dv Composition, segregation; defects and impurities
78.70.Dm X-ray absorption spectra
75.70.Ak Magnetic properties of monolayers and thin films
75.50.Pp Magnetic semiconductors
75.50.Dd Nonmetallic ferromagnetic materials
68.55.-a Thin film structure and morphology
68.55.Nq Composition and phase identification
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
61.46.-w Structure of nanoscale materials

Charge state dependence of the diffusivity of interstitial Fe in silicon detected by Mössbauer spectroscopy

H. P. Gunnlaugsson, G. Weyer, M. Dietrich, M. Fanciulli, K. Bharuth-Ram, and R. Sielemann

Appl. Phys. Lett. 80, 2657 (2002); http://dx.doi.org/10.1063/1.1469216 (3 pages) | Cited 10 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Interstitial 57mFe atoms excited in the 14.4 keV Mössbauer state have been created in silicon at 400–800 K as a result of the recoil imparted on these daughter atoms in the β− decay of ion-implanted, substitutional 57Mn. Diffusional jumps of the interstitial 57mFe cause a line broadening in their Mössbauer spectra, which is directly proportional to their diffusivity. Thus, the charge-state-dependent diffusivity has been determined in differently doped material. © 2002 American Institute of Physics.
Show PACS
66.30.J- Diffusion of impurities
81.05.Cy Elemental semiconductors
61.72.J- Point defects and defect clusters
76.80.+y Mössbauer effect; other γ-ray spectroscopy

Structural properties of magnetically anisotropic SmCo5 ribbons

Long Li, Wen-yong Zhang, Yu-qing Zhou, Jian-qi Li, Bao-gen Shen, and Jian Zhang

Appl. Phys. Lett. 80, 2660 (2002); http://dx.doi.org/10.1063/1.1469210 (3 pages) | Cited 2 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The structural features of magnetically anisotropic SmCo5 ribbons prepared by melt spinning have been investigated by means of transmission electron microscopy. It was determined that this kind of SmCo5 ribbons are made up of structural domains, which consist of layered grains regularly packed along the c-axis direction. The c axes of the grains generally lie in the ribbon plane and along the length. The SmCo5 grains are well crystallized in the conventional hexagonal structure (P6/mmm). The properties of grain boundaries either with or without impurity phases have been systematically analyzed. © 2002 American Institute of Physics.
Show PACS
61.66.Dk Alloys
75.50.Cc Other ferromagnetic metals and alloys
61.72.Mm Grain and twin boundaries
75.30.Gw Magnetic anisotropy
75.50.Ww Permanent magnets

Structural studies of annealed ultrathin La0.8MnO3 films

Q. Qian, T. A. Tyson, C. Dubourdieu, A. Bossak, J. P. Sénateur, M. Deleon, J. Bai, and G. Bonfait

Appl. Phys. Lett. 80, 2663 (2002); http://dx.doi.org/10.1063/1.1470689 (3 pages) | Cited 2 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A detailed study of the long-range, nanoscale, and local structure of La0.8MnO3 films of varying thickness was performed. These measurements give insight on the relative volumes of the insulating and metallic regions. A thin metallic surface region is found in all films. The nature of the film growth is also discussed. © 2002 American Institute of Physics.
Show PACS
68.55.-a Thin film structure and morphology
75.50.Dd Nonmetallic ferromagnetic materials
75.47.De Giant magnetoresistance
75.70.Ak Magnetic properties of monolayers and thin films
68.37.Ps Atomic force microscopy (AFM)
78.70.Dm X-ray absorption spectra
61.46.-w Structure of nanoscale materials
75.50.Tt Fine-particle systems; nanocrystalline materials
81.07.Bc Nanocrystalline materials

Extended phase diagrams for guiding plasma-enhanced chemical vapor deposition of silicon thin films for photovoltaics applications

A. S. Ferlauto, R. J. Koval, C. R. Wronski, and R. W. Collins

Appl. Phys. Lett. 80, 2666 (2002); http://dx.doi.org/10.1063/1.1469661 (3 pages) | Cited 22 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Real time spectroscopic ellipsometry has been applied to develop extended phase diagrams that can guide the deposition of hydrogenated silicon (Si:H) thin films for highest performance solar cells. Previous such studies have shown that optimization of amorphous Si:H intrinsic layers by rf plasma-enhanced chemical vapor deposition (PECVD) is achieved using the maximum possible H2 dilution of SiH4 while avoiding a transition to the mixed-phase (amorphous+microcrystalline) growth regime. In this study, we propose that optimization of amorphous Si:H in higher rate rf PECVD processes further requires the largest possible thickness onset for a surface roughening transition detected in the amorphous film growth regime. © 2002 American Institute of Physics.
Show PACS
81.05.Gc Amorphous semiconductors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
84.60.Jt Photoelectric conversion
81.30.Dz Phase diagrams of other materials
61.43.Dq Amorphous semiconductors, metals, and alloys
52.77.Dq Plasma-based ion implantation and deposition
68.55.A- Nucleation and growth
64.70.-p Specific phase transitions
68.35.B- Structure of clean surfaces (and surface reconstruction)

First-principles study of transition-metal aluminates as high-k gate dielectrics

Michael Haverty, Atsushi Kawamoto, Kyeongjae Cho, and Robert Dutton

Appl. Phys. Lett. 80, 2669 (2002); http://dx.doi.org/10.1063/1.1467979 (3 pages) | Cited 13 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The semiconductor industry is searching for a high-k gate dielectric replacement for silica. We study the electronic properties of Nb, Zr, Y, and Sc aluminates using density functional theory to screen aluminates for further study. The transition metals substituted favorably at the octahedral Al sites in the κ-alumina model system. Zirconium and niobium substitution for Al introduced localized d-electron states 0.6 and 1.1 eV below the conduction band. Yttrium and scandium introduced states 0.1 and 1.4 eV above the delocalized s and p states of the conduction band causing little change in the κ-alumina band gap and are promising replacement candidates that maintain the large alumina band offset. © 2002 American Institute of Physics.
Show PACS
71.20.Ps Other inorganic compounds
71.15.Mb Density functional theory, local density approximation, gradient and other corrections
77.84.-s Dielectric, piezoelectric, ferroelectric, and antiferroelectric materials

Effective thermodynamic elastic constants under finite deformation

D. J. Dunstan, S. H. B. Bosher, and J. R. Downes

Appl. Phys. Lett. 80, 2672 (2002); http://dx.doi.org/10.1063/1.1469658 (3 pages) | Cited 5 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Nonlinear elasticity is required to account for mechanical and acoustic properties of bodies under finite elastic deformation. R. N. Thurston and K. Brugger gave equations [Phys. Rev. 133, A1604 (1964)] relating experimental acoustic velocities in a strained elastic body to the thermodynamic third-order elastic constants cIJK given in data books. However, no correct and complete set of expressions has been given for the general case, to obtain effective elastic constants from the cIJK to solve mechanical or physical problems. By considering two deformations applied to an elastic body, effective thermodynamic second-order constants cIJ under finite strain are defined thermodynamically and correctly related to the Lagrangian and Eulerian third-order elastic stiffness constants, cIJK. © 2002 American Institute of Physics.
Show PACS
62.20.D- Elasticity
65.40.G- Other thermodynamical quantities
62.65.+k Acoustical properties of solids

Electron-beam-induced optical memory effects in GaN

Y. C. Chang, A. L. Cai, M. A. L. Johnson, J. F. Muth, R. M. Kolbas, Z. J. Reitmeier, S. Einfeldt, and R. F. Davis

Appl. Phys. Lett. 80, 2675 (2002); http://dx.doi.org/10.1063/1.1469222 (3 pages) | Cited 6 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Metastable effects in unintentionally doped GaN films grown on SiC substrates have been investigated using cathodoluminescence (CL). Memory effect patterns produced optically are observed in CL images. An electron beam can also produce memory effect patterns and the resulting changes in the luminescence spectra are quite similar for either optical or electron-beam-induced patterns. CL spectra reveal that the yellow luminescence at 2.2 eV increases significantly with little change in the band-edge emission in both cases. Samples that do not exhibit optically induced memory effects are also investigated and do not exhibit electron-beam-induced patterns, either. Monochromatic CL images at 540 and 365 nm confirm the similarity of optically and electron-beam-induced memory effects based on changes in luminescence spectra. © 2002 American Institute of Physics.
Show PACS
78.66.Fd III-V semiconductors
78.60.Hk Cathodoluminescence, ionoluminescence
78.55.Cr III-V semiconductors
back to top
RSS Feeds

Low leakage current Cu(Ti)/SiO2 interconnection scheme with a self-formed TiOx diffusion barrier

C. J. Liu and J. S. Chen

Appl. Phys. Lett. 80, 2678 (2002); http://dx.doi.org/10.1063/1.1468913 (3 pages) | Cited 30 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Electrical and material properties of Cu(0.02 wt % Ti) alloy and pure Cu films deposited on SiO2/Si are explored. Current–voltage measurement using metal–oxide–semiconductor (MOS) capacitor structure reveals low leakage current (10−8 A/cm2) for capacitors with as-deposited Cu(0.02 wt % Ti) and pure Cu metal gates. However, after annealing at 700 °C in a vacuum, leakage current of MOS capacitors using a pure Cu gate shows a dramatic rise of leakage current at a low electrical field, while the leakage current of capacitors with Cu(0.02 wt % Ti) gate stays at ∼ 10−7 A/cm2. Concurrently, the resistivity of annealed Cu(0.02 wt % Ti) is reduced to 2.5 μΩ cm, which is only slightly greater than the resistivity of as-sputtered pure Cu films. X-ray photoelectron spectroscopy indicates that a TiOx layer has formed at the Cu(0.02 wt % Ti)/SiO2 interface after annealing and Auger electron spectrometry depth profiles show less interdiffusion at the Cu(0.02 wt % Ti)/SiO2 interface than the Cu/SiO2 interface. The correlation between leakage current reliability and the interfacial reaction upon annealing is discussed. © 2002 American Institute of Physics.
Show PACS
73.40.Ns Metal-nonmetal contacts
85.40.Ls Metallization, contacts, interconnects; device isolation
68.35.Fx Diffusion; interface formation
84.32.Tt Capacitors
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
85.30.Tv Field effect devices
61.72.Cc Kinetics of defect formation and annealing
79.60.Jv Interfaces; heterostructures; nanostructures
79.20.Fv Electron impact: Auger emission

Designed emitter states in resonant tunneling through quantum dots

T. Bryllert, M. Borgstrom, T. Sass, B. Gustafson, L. Landin, L.-E. Wernersson, W. Seifert, and L. Samuelson

Appl. Phys. Lett. 80, 2681 (2002); http://dx.doi.org/10.1063/1.1469686 (3 pages) | Cited 14 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Resonant tunneling through a single layer of self-assembled quantum dots (QDs) is compared to tunneling through two layers of vertically aligned (stacked) dots. The difference can be viewed as going from a two-dimensional emitter to a zero-dimensional emitter. The temperature dependence of current peaks originating in tunneling through individual QDs and individual stacks is used to clarify this point. In addition, we show that the statistical size distribution of self-assembled quantum dots causing the inhomogeneous broadening in luminescence experiments can be analyzed in a resonant tunneling experiment. © 2002 American Institute of Physics.
Show PACS
85.30.Mn Junction breakdown and tunneling devices (including resonance tunneling devices)
85.30.Kk Junction diodes
73.21.La Quantum dots
73.23.Hk Coulomb blockade; single-electron tunneling

Piezoelectric effect on Al0.35−δInδGa0.65N/GaN heterostructures

Ikai Lo, J. K. Tsai, Li-Wei Tu, K. Y. Hsieh, M. H. Tsai, C. S. Liu, J. H. Huang, S. Elhamri, W. C. Mitchel, and J. K. Sheu

Appl. Phys. Lett. 80, 2684 (2002); http://dx.doi.org/10.1063/1.1469209 (3 pages) | Cited 7 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Al0.35−δInδGa0.65N/GaN heterostructures have been studied by using transmission electron microscopy, photoluminescence, and Shubnikov–de Haas (SdH) measurements. In the sample of δ<0.01%, two SdH oscillations beat each other due to the population of the lowest two subbands. The carrier concentrations of these two subbands are 1.398 and 1.248×1013 cm−2 and the electric field at the interface is reduced to 2.19×104 V/cm, which is one order of magnitude smaller than that of Al0.35Ga0.65N/GaN heterostructure. We suggest that a small fraction of In atoms in the Al0.35−δInδGa0.65N can be used as a tuning parameter to control the strain and the piezoelectric field at the interface. © 2002 American Institute of Physics.
Show PACS
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
77.65.Ly Strain-induced piezoelectric fields
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
78.55.Cr III-V semiconductors
72.20.My Galvanomagnetic and other magnetotransport effects

Two-dimensional dopant concentration profiles from ultrashallow junction metal-oxide-semiconductor field-effect transistors using the etch/transmission electron microscopy method

K. D. Yoo, C. D. Marsh, and G. R. Booker

Appl. Phys. Lett. 80, 2687 (2002); http://dx.doi.org/10.1063/1.1469652 (3 pages) | Cited 3 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The etch/transmission electron microscopy (TEM) method for obtaining one dimensional (1D) and two dimensional (2D) dopant concentration profiles has been developed and applied to n+/p silicon metal-oxide-semiconductor field-effect transistor (MOSFET) structures fabricated using 0.25 μm device technology with ultrashallow source/drain junctions obtained by 5-keV arsenic ion implantation. Cross-section thin-foil specimens were dopant selectively etched with 0.5%HF/99.5%HNO3. Local etch rates were determined from TEM thickness fringes and converted to dopant concentrations using an independently determined calibration curve. The profiles indicated a vertical junction depth of ∼ 51 nm, a lateral junction distance under the gate edge of ∼ 27 nm, and an effective gate length of ∼ 161 nm. The etch/TEM 1D dopant concentration profiles agreed well with spreading resistance probe and secondary ion mass spectroscopy 1D dopant concentration profiles obtained from blanket silicon wafers similarly processed. © 2002 American Institute of Physics.
Show PACS
85.30.Tv Field effect devices
81.05.Cy Elemental semiconductors
61.72.uf Ge and Si
81.65.Cf Surface cleaning, etching, patterning
85.40.Ry Impurity doping, diffusion and ion implantation technology

Quantum size effects in PbSe quantum wells

E. I. Rogacheva, T. V. Tavrina, O. N. Nashchekina, S. N. Grigorov, K. A. Nasedkin, M. S. Dresselhaus, and S. B. Cronin

Appl. Phys. Lett. 80, 2690 (2002); http://dx.doi.org/10.1063/1.1469677 (3 pages) | Cited 17 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In PbSe epitaxial thin films grown by thermal evaporation on KCl(001) substrates and covered with an EuS protective layer, oscillatory dependences of the galvanomagnetic and thermoelectric properties (electrical conductivity σ, the Hall coefficient RH, charge carrier mobility μ, and the Seebeck coefficient S) on the PbSe layer thickness d (3<d<200 nm) were observed at room temperature. Oscillations of the transport properties are associated with quantum size effects due to electron confinement in the PbSe quantum wells. © 2002 American Institute of Physics.
Show PACS
73.63.Hs Quantum wells
68.65.Fg Quantum wells
72.20.My Galvanomagnetic and other magnetotransport effects
72.20.Pa Thermoelectric and thermomagnetic effects
72.20.Fr Low-field transport and mobility; piezoresistance

Isotope effects on the rate of electron-beam dissociation of Mg–H complexes in GaN

C. H. Seager, S. M. Myers, B. Vaandrager, and J. S. Nelson

Appl. Phys. Lett. 80, 2693 (2002); http://dx.doi.org/10.1063/1.1468917 (3 pages) | Cited 11 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The effect of low-energy electron-beam irradiation on the stability of acceptor–hydrogen complexes in Mg-doped GaN has been directly examined with infrared optical spectroscopy. Consistent with prior electrical transport data, we find that Mg–H pairs begin to break apart under 25 keV electron-beam exposure at doses of a few mC/cm2. However, we find that, even after long exposures, roughly ½ of the acceptor–hydrogen pairs remain unaffected by the electron exposure. Using Mg-doped samples that have been vacuum annealed and D2 gas exposed, we demonstrate that there is a large (∼×5) isotopic shift in the beam-induced debonding rate of these acceptor–hydrogen complexes. H and D remain in the material during these treatments, and Mg–H or Mg–D reforms during postirradiation annealing. The implications of these observations for understanding the nature of the debonding process and the subsequent reactions of the detached H/D in the GaN lattice are discussed. © 2002 American Institute of Physics.
Show PACS
78.30.Fs III-V and II-VI semiconductors
71.55.Eq III-V semiconductors
61.80.Fe Electron and positron radiation effects
61.82.Fk Semiconductors
61.72.Cc Kinetics of defect formation and annealing

Nitrogen-induced transient enhanced diffusion of dopants

Cheruvu Murthy, Kilho Lee, Rajesh Rengarajan, Omer Dokumaci, Paul Ronsheim, Helmut Tews, and Satoshi Inaba

Appl. Phys. Lett. 80, 2696 (2002); http://dx.doi.org/10.1063/1.1470692 (3 pages) | Cited 5 times

Online Publication Date: 10 April 2002

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Studies of both systematic experiments and detailed simulations for examining the effects of N2+ implant on channel dopants are described. Step-by-step monitor wafer experiments have clearly confirmed the nitrogen-induced transient enhanced diffusion (TED) of dopants. Process simulations within the +1 N2+ profile approach have demonstrated the need to scale down the +1 model parameter for matching the measured depth profiles. The underlying mechanism for the reduced +1 model parameter is that nitrogen which diffuses toward the Si surface becomes a sink for the interstitials. These combined studies also show that nitrogen-induced TED of dopants increases with N2+ dose. © 2002 American Institute of Physics.
Show PACS
66.30.J- Diffusion of impurities
61.72.S- Impurities in crystals
61.72.uf Ge and Si
61.82.Fk Semiconductors
61.72.Cc Kinetics of defect formation and annealing
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
61.72.J- Point defects and defect clusters
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces
Page 1 of 3 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close