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

11 Aug 1997

Volume 71, Issue 6, pp. 729-854

Page 2 of 2 Pages Previous Page | Jump to Page

Transient analysis of ballistic transport in stublike quantum waveguides

L. Burgnies, O. Vanbésien, and D. Lippens

Appl. Phys. Lett. 71, 803 (1997); http://dx.doi.org/10.1063/1.119651 (3 pages) | Cited 6 times

Full Text: | Download PDF

Show Abstract
Switching properties of a T-shaped quantum waveguide are studied by solving the two-dimensional time-dependent Schrödinger equation under continuous injection. Assuming a ballistic electron transport, the conductance transient alternately overshoots and undershoots the steady-state value and shows a self-sustaining harmonic oscillation in the long-time limit. Analysis by Fourier transform resolves the various spectral contributions in the terahertz range and it is found that the quantum system keeps a memory of its initial state at short times. Pronounced mixing effects are shown with an electron wave function shared between the bound and metastables states of the initial and final eigenspectra. © 1997 American Institute of Physics.  
Show PACS
73.23.Ad Ballistic transport
85.35.Ds Quantum interference devices
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)

Halogen impurities in silicon: Shallow single donors

D. J. Chadi

Appl. Phys. Lett. 71, 806 (1997); http://dx.doi.org/10.1063/1.119652 (3 pages) | Cited 4 times

Full Text: | Download PDF

Show Abstract
From the results of first-principles calculations, we find that substitutional Cl, and Br and I impurities in Si are stable shallow single donor dopants that are mostly immune to deactivation processes preventing superhigh n doping of Si with column V impurities. In the absence of acceptor impurities, such as H and F, room-temperature carrier densities above 1020/cm3 are proposed to be possible, particularly with Cl, which causes the least lattice strain. © 1997 American Institute of Physics.
Show PACS
71.55.Cn Elemental semiconductors

Observation of vertical and lateral Ge segregation in thin undulating SiGe layers on Si by electron energy-loss spectroscopy

T. Walther, C. J. Humphreys, and A. G. Cullis

Appl. Phys. Lett. 71, 809 (1997); http://dx.doi.org/10.1063/1.119653 (3 pages) | Cited 51 times

Full Text: | Download PDF

Show Abstract
The local Ge composition in undulating Si0.8Ge0.2 layers on Si has been studied in a scanning transmission electron microscope using electron energy-loss spectroscopy. We observe Ge enrichment of the SiGe layer near the free surface (vertical Ge segregation in the growth direction) as well as Ge depletion of the ripple troughs compared to the peaks (lateral segregation). These lateral compositional fluctuations are likely to retard the generation of misfit dislocations and might be relevant to the Stranski–Krastanov growth of strained epitaxial alloy layers as well as to the self-organized growth of quantum dot structures. © 1997 American Institute of Physics.
Show PACS
64.75.-g Phase equilibria
68.35.Fx Diffusion; interface formation
61.85.+p Channeling phenomena (blocking, energy loss, etc.)
79.20.Kz Other electron-impact emission phenomena
61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)

Stimulated emission at 34 K from an optically pumped cubic GaN/AlGaN heterostructure grown by metalorganic vapor-phase epitaxy

Atsushi Nakadaira and Hidenao Tanaka

Appl. Phys. Lett. 71, 812 (1997); http://dx.doi.org/10.1063/1.119654 (3 pages) | Cited 9 times

Full Text: | Download PDF

Show Abstract
A cubic GaN/AlGaN heterostructure has been grown on a GaAs (100) substrate by metalorganic vapor-phase epitaxy under low V/III ratio conditions, which resulted in a flat GaN layer. Stimulated emission was observed at 387 nm from the cleaved edge of an optically pumped cubic GaN/AlGaN heterostructure at 34 K. The threshold power density was 2.4 MW/cm2. © 1997 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
81.05.Ea III-V semiconductors
78.45.+h Stimulated emission
81.15.Kk Vapor phase epitaxy; growth from vapor phase
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation
78.66.Fd III-V semiconductors

Room temperature differential negative resistance in an Al/Zn0.61Cd0.39Se/n+-InP device

Kai Shum, J. Zhou, W. Zhang, L. Zeng, and M. C. Tamargo

Appl. Phys. Lett. 71, 815 (1997); http://dx.doi.org/10.1063/1.119655 (2 pages)

Full Text: | Download PDF

Show Abstract
Experimental data are presented on the current–voltage characteristics of an Al/ZnCdSe/n+-InP device from 77 to 300 K. A strong negative differential resistance under forward bias was observed for temperature higher than 145 K. The peak-to-valley current ratio was measured to be 30 at room temperature. In the reverse bias region the device behaves as a leaky Schottky diode. © 1997 American Institute of Physics.
Show PACS
85.30.Kk Junction diodes
85.30.Hi Surface barrier, boundary, and point contact devices
73.61.Ey III-V semiconductors

Evolution of the Coulomb gap in tunnel-coupled quantum dots

C. H. Crouch, C. Livermore, R. M. Westervelt, K. L. Campman, and A. C. Gossard

Appl. Phys. Lett. 71, 817 (1997); http://dx.doi.org/10.1063/1.119656 (3 pages) | Cited 20 times

Full Text: | Download PDF

Show Abstract
We report differential conductance measurements through a double quantum dot with adjustable interdot tunneling rate. The Coulomb gap of the double dot decreases continuously as the interdot tunnel conductance Gint is increased, from the gap of two isolated dots (when Gint ∼ 0) to the gap of a single large dot of twice the total capacitance (when Gint = 2e2/h). Excited electronic states in differential conductance measurements on single dots show a spectrum which is essentially independent of the number of electrons in the dot, but is not uniform. © 1997 American Institute of Physics.
Show PACS
73.61.Ey III-V semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions

Carrier capture in pseudomorphically strained wurtzite GaN quantum-well lasers

Jin Wang, K. W. Kim, and M. A. Littlejohn

Appl. Phys. Lett. 71, 820 (1997); http://dx.doi.org/10.1063/1.119657 (3 pages) | Cited 3 times

Full Text: | Download PDF

Show Abstract
The generalized photon-carrier rate-equation formalism is used to evaluate the carrier capture process in pseudomorphically strained wurtzite GaN quantum-well lasers. Our results show that both the carrier capture time and the carrier escape time vary significantly with the injected carrier density and strain-induced piezoelectric field. Thus, it is demonstrated that in place of the flatband conditions adopted in most treatments, a self-consistent adjustment of the carrier capture process is essential for achieving an accurate description of carrier dynamics in wurtzite GaN quantum-well lasers. © 1997 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
77.65.Ly Strain-induced piezoelectric fields

Free electron laser annealing of N-ion-implanted 3C-SiC films

Hideaki Ohyama, Toshiji Suzuki, Kazuhisa Nishi, Tsuneo Mitsuyu, and Takio Tomimasu

Appl. Phys. Lett. 71, 823 (1997); http://dx.doi.org/10.1063/1.119668 (3 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
Infrared laser annealing at a variety of wavelengths (10.0–13.0 μm) was performed under room temperature for cubic silicon carbide (3C-SiC) films after N-ion implantation by using a free electron laser with features of wide-range tunability, ultrashort pulse operation ( ∼ 10 ps), and intense peak power ( ∼ MW). Infrared absorption spectroscopy indicated that the annealing at 12.6 μm, which corresponds to the absorption peak of Si–C stretch mode, was effective for removing the crystalline damage induced by the ion implantation. On the other hand, Hall effect measurements showed an increase of carrier density for samples annealed at around 10.4 μm, whereas the absorption was weak at this wavelength. This important result is most likely attributed to the activation of N donors caused by the direct excitation of a local vibration mode associated with N atoms in the SiC matrix. © 1997 American Institute of Physics.
Show PACS
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
61.72.Cc Kinetics of defect formation and annealing
61.72.up Other materials
61.80.Jh Ion radiation effects
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
85.40.Ry Impurity doping, diffusion and ion implantation technology
78.30.Hv Other nonmetallic inorganics
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
63.20.Pw Localized modes
71.55.Ht Other nonmetals
73.61.Le Other inorganic semiconductors

Experimental observation of conductance transients in Al/SiNx:H/Si metal-insulator-semiconductor structures

S. Dueñas, R. Pelaez, E. Castan, R. Pinacho, L. Quintanilla, J. Barbolla, I. Martil, and G. Gonzalez-Diaz

Appl. Phys. Lett. 71, 826 (1997); http://dx.doi.org/10.1063/1.119658 (3 pages) | Cited 16 times

Full Text: | Download PDF

Show Abstract
Room temperature conductance transients in the SiNx:H/Si interface are reported. Silicon nitride thin films were directly deposited on silicon by the low temperature electron-cyclotron-resonance plasma method. The shape of the conductance transients varies with the frequency at which they are obtained. This behavior is explained in terms of a disorder-induced gap-state continuum model for the interfacial defects. A perfect agreement between experiment and theory is obtained proving the validity of the model. © 1997 American Institute of Physics.
Show PACS
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
73.20.At Surface states, band structure, electron density of states
73.61.Cw Elemental semiconductors

Strain determination in heteroepitaxial GaN

B. J. Skromme, H. Zhao, D. Wang, H. S. Kong, M. T. Leonard, G. E. Bulman, and R. J. Molnar

Appl. Phys. Lett. 71, 829 (1997); http://dx.doi.org/10.1063/1.119659 (3 pages) | Cited 32 times

Full Text: | Download PDF

Show Abstract
Residual strains have been evaluated in a variety of GaN layers grown on sapphire or 6H-SiC from wafer curvature at 293 K, which avoids needing to know the unstrained lattice parameters or energy gap of GaN in advance. Estimated strains at 1.7 K are correlated with the energy of the A free exciton to determine its strain dependence. We find that strain-free GaN has an A exciton energy of 3.468±0.002 eV at 1.7 K, and 293 K lattice parameters a = 3.1912 Å and c = 5.1836 Å. These values imply that GaN on SiC is frequently under net biaxial compressive stress due to residual lattice mismatch stress, and that several hundred μm thick GaN layers on sapphire and homoepitaxial layers grown on bulk platelets grown at high pressure are both under about 1×10−3 in-plane compressive strain. These conclusions conflict with most previous assumptions. © 1997 American Institute of Physics.
Show PACS
68.60.Bs Mechanical and acoustical properties
68.55.-a Thin film structure and morphology
68.35.Gy Mechanical properties; surface strains
68.35.Ct Interface structure and roughness
71.35.Cc Intrinsic properties of excitons; optical absorption spectra
78.55.Cr III-V semiconductors
78.66.Fd III-V semiconductors
78.20.hb Piezo-optical, elasto-optical, acousto-optical, and photoelastic effects

Low energy proton-induced displacement damage in shielded GaAs solar cells in space

G. P. Summers, S. R. Messenger, E. A. Burke, M. A. Xapsos, and R. J. Walters

Appl. Phys. Lett. 71, 832 (1997); http://dx.doi.org/10.1063/1.119660 (3 pages) | Cited 9 times

Full Text: | Download PDF

Show Abstract
The energy dependence of the cumulative fraction of the damage produced by protons in shielded GaAs solar cells in space is presented. The results show that typically <20% of the damage is produced by protons emerging into the cell with energies <0.1 MeV, including those protons that stop in the active regions of the cell. © 1997 American Institute of Physics.
Show PACS
84.60.Jt Photoelectric conversion
61.80.Jh Ion radiation effects
61.85.+p Channeling phenomena (blocking, energy loss, etc.)

Electrical properties of Na-incorporated Cu(In1−xGax)3Se5 thin films

Naoki Kohara, Takayuki Negami, Mikihiko Nishitani, Yasuhiro Hashimoto, and Takahiro Wada

Appl. Phys. Lett. 71, 835 (1997); http://dx.doi.org/10.1063/1.119661 (3 pages) | Cited 5 times

Full Text: | Download PDF

Show Abstract
Na-incorporated Cu(In1−xGax)3Se5(Cu(In1−xGax)3Se5:Na) films were prepared by the deposition of Cu(In1−xGax)3Se5 layers on Na2S-coated substrates. Electrical properties of the Cu(In1−xGax)3Se5:Na films were evaluated by I–V and spectral response measurements of devices with an ITO/ZnO/CdS/Cu(In1−xGax)3Se5:Na/Mo/glass structure. The Cu(In1−xGax)3Se5:Na films with x>0 showed p-type conduction, whereas for Cu(In1−xGax)3Se5 without the addition of Na2S, films with x<0.3 showed n-type conduction. The addition of Na was found to have a strong influence on the electrical properties of Cu(In1−xGax)3Se5 films as well as Cu(In1−xGax)Se2 films. © 1997 American Institute of Physics.
Show PACS
73.61.Le Other inorganic semiconductors
72.80.Jc Other crystalline inorganic semiconductors
73.50.Dn Low-field transport and mobility; piezoresistance
72.20.Fr Low-field transport and mobility; piezoresistance
73.50.Pz Photoconduction and photovoltaic effects
72.40.+w Photoconduction and photovoltaic effects

Direct measurement of population-induced broadening of quantum well intersubband transitions

Yuanjian Xu, Gilad Almogy, John O’Brien, Ali Shakouri, Weihua Xu, Randal A. Salvatore, and Amnon Yariv

Appl. Phys. Lett. 71, 838 (1997); http://dx.doi.org/10.1063/1.119662 (3 pages) | Cited 2 times

Full Text: | Download PDF

Show Abstract
The dependence of the absorption spectral linewidth of quantum well intersubband transitions on the electron population in the well is experimentally demonstrated. We show that the dependence of the spectral linewidth on the population is substantial and accounts for some of the broadening previously attributed to donor scattering. © 1997 American Institute of Physics.
Show PACS
78.66.Fd III-V semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
73.20.At Surface states, band structure, electron density of states
78.30.Fs III-V and II-VI semiconductors

Thermal stability of YBa2Cu3O7−x single crystal surfaces investigated by the ion channeling technique

F. Wang, H. Zama, H. Ohtsuka, M. Sato, and T. Morishita

Appl. Phys. Lett. 71, 841 (1997); http://dx.doi.org/10.1063/1.119663 (3 pages)

Full Text: | Download PDF

Show Abstract
We have performed ion channeling characterizations on the (001) and (100) surfaces of YBa2Cu3O7−x single crystals, using 950 keV He+ ions at temperatures ranging from 20 to 780 °C. In oxygen pressures below 5×10−5 Torr, we directly observed the surface changes as the sample temperature was increased, and found that the compositional and structural changes occurred from around 400 °C. At higher oxygen pressures, we heated the crystals and performed channeling analysis before and after the heating. We found that the YBa2Cu3O7−x crystal surfaces were stable at temperatures up to 780 °C in the oxygen pressure range of 1 mTorr–1 Torr. Beyond this range, the surfaces deteriorated at high temperatures. © 1997 American Institute of Physics.
Show PACS
74.72.-h Cuprate superconductors
68.35.B- Structure of clean surfaces (and surface reconstruction)
61.80.Jh Ion radiation effects
61.85.+p Channeling phenomena (blocking, energy loss, etc.)
81.40.Gh Other heat and thermomechanical treatments
74.25.-q Properties of superconductors

Preparation and properties of triple perovskite La3−3xCa1+3xMn3O10 ferromagnetic thin films

H. Asano, J. Hayakawa, and M. Matsui

Appl. Phys. Lett. 71, 844 (1997); http://dx.doi.org/10.1063/1.119664 (3 pages) | Cited 28 times

Full Text: | Download PDF

Show Abstract
The ferromagnetic compound La3−3xCa1+3xMn3O10 with a triple perovskite structure can be successfully synthesized by using a thin-film growth method. Sputtered a-axis thin films with x = 0.3 have been examined with respect to their magnetotransport properties. For the triple perovskite compound, we have observed the features, including the enhanced magnetoresistene (MR) effect and the characteristic low-temperature MR effect resulting from intragrain spin-polarized tunneling, which were reported for the double perovskite manganites. A comparison of the magnitude of these features in triple and double perovskite manganites suggests that the features are actually determined by the c-axis Mn–O bond configuration in a layered-perovskite ferromagnet. © 1997 American Institute of Physics.
Show PACS
75.47.De Giant magnetoresistance
75.50.Cc Other ferromagnetic metals and alloys
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
81.15.Cd Deposition by sputtering
81.05.Je Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides)
73.61.Ng Insulators

Synchrotron radiation micro-Fourier transform infrared spectroscopy applied to photoresist imaging

L. E. Ocola, F. Cerrina, and Tim May

Appl. Phys. Lett. 71, 847 (1997); http://dx.doi.org/10.1063/1.119665 (3 pages) | Cited 4 times

Full Text: | Download PDF

Show Abstract
The application of a micro-Fourier transform infrared, (μ-FTIR), spectroscopic system, using synchrotron radiation as a light source, for photoresist chemical analysis has been investigated. The better signal to noise due to the high brightness of the infrared radiation from the synchrotron permits higher spatial resolution scans than with a conventional glowbar. This permits a new technique of μ-FTIR spectroscopy, which potentially can get close to diffraction limited resolution, with high chemical sensitivity, for mid-IR wavelengths ranging from 2.3 μm (4400 cm−1) to 9 μm (1100 cm−1). An example of application of imaging the local chemistry changes of a chemically amplified photoresist with post-exposure bake shows the exciting capability of this technique for nondestructive resist exposure process control. © 1997 American Institute of Physics.
Show PACS
82.80.Ms Mass spectrometry (including SIMS, multiphoton ionization and resonance ionization mass spectrometry, MALDI)
85.40.Hp Lithography, masks and pattern transfer
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
82.50.-m Photochemistry

Modeling of electrical conductance variation in substrate during initial growth of ultra thin film

Seok-Kyun Song, Hyung-Jin Jung, Seok-Keun Koh, and Hong-Koo Baik

Appl. Phys. Lett. 71, 850 (1997); http://dx.doi.org/10.1063/1.119666 (2 pages) | Cited 2 times

Full Text: | Download PDF

Show Abstract
A model of the electrical conductance of a resistive or semiconductive substrate, as a function of the average thickness d of a deposited film in initial growth on the substrate is proposed. The total conductance has two terms: one proportional to d2/3 for three-dimension (3D) growth, and one proportional to d for 2D growth or for increasing number of islands. The model was applied to the conductance of a Sn film deposited on a SiOx substrate showing that the initial growth is dominated by 3D growth. The proposed model may be useful for in situ study of the growth of ultra thin films prior to the onset of tunneling conductance. © 1997 American Institute of Physics.
Show PACS
73.61.At Metal and metallic alloys
73.25.+i Surface conductivity and carrier phenomena
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
81.05.Bx Metals, semimetals, and alloys

Laser-induced acoustic desorption of electrons and ions

V. V. Golovlev, S. L. Allman, W. R. Garrett, and C. H. Chen

Appl. Phys. Lett. 71, 852 (1997); http://dx.doi.org/10.1063/1.119667 (3 pages) | Cited 9 times

Full Text: | Download PDF

Show Abstract
Laser irradiation of absorbing materials can be used to generate acoustic pulses with extremely high amplitude and short pulse duration. Such acoustic pulses can transfer energy and momentum to atomic particles on solid surfaces to cause desorption of the particles. We report experimental observations of the effect of laser-induced acoustic desorption (LIAD) of electrons from metal film surfaces and hydrogen ions from the surface of palladium saturated with hydrogen. We believe LIAD can be used as a gentle technique to transfer analyte molecules and ions into gas phase for mass analysis and for other applications. © 1997 American Institute of Physics.
Show PACS
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
79.20.Ds Laser-beam impact phenomena
68.03.Fg Evaporation and condensation of liquids
68.43.Mn Adsorption kinetics
79.20.La Photon- and electron-stimulated desorption
Page 2 of 2 Pages Previous Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close