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

18 May 1998

Volume 72, Issue 20, pp. 2499-2618

Page 2 of 2 Pages Previous Page | Jump to Page
back to top
RSS Feeds

Negative electron affinity mechanism for diamond surfaces

I. L. Krainsky and V. M. Asnin

Appl. Phys. Lett. 72, 2574 (1998); http://dx.doi.org/10.1063/1.121422 (3 pages) | Cited 30 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The energy distribution of the secondary electrons for chemical vacuum deposited diamond films with negative electron affinity (NEA) was investigated. It was found that while for completely hydrogenated diamond surfaces the negative electron affinity peak in the energy spectrum of the secondary electrons is present for any energy of the primary electrons, for partially hydrogenated diamond surfaces there is a critical energy above which the peak is present in the spectrum. This critical energy increases sharply when hydrogen coverage of the diamond surface diminishes. This effect was explained by the change of the NEA from the true type for the completely hydrogenated surface to the effective type for the partially hydrogenated surfaces.
Show PACS
73.20.At Surface states, band structure, electron density of states
79.20.Hx Electron impact: secondary emission

Tuning the emission wavelength of Si nanocrystals in SiO2 by oxidation

M. L. Brongersma, A. Polman, K. S. Min, E. Boer, T. Tambo, and H. A. Atwater

Appl. Phys. Lett. 72, 2577 (1998); http://dx.doi.org/10.1063/1.121423 (3 pages) | Cited 115 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Si nanocrystals (diameter 2–5 nm) were formed by 35 keV Si+ implantation at a fluence of 6×1016 Si/cm2 into a 100 nm thick thermally grown SiO2 film on Si (100), followed by thermal annealing at 1100 °C for 10 min. The nanocrystals show a broad photoluminescence spectrum, peaking at 880 nm, attributed to the recombination of quantum confined excitons. Rutherford backscattering spectrometry and transmission electron microscopy show that annealing these samples in flowing O2 at 1000 °C for times up to 30 min results in oxidation of the Si nanocrystals, first close to the SiO2 film surface and later at greater depths. Upon oxidation for 30 min the photoluminescence peak wavelength blueshifts by more than 200 nm. This blueshift is attributed to a quantum size effect in which a reduction of the average nanocrystal size leads to emission at shorter wavelengths. The room temperature luminescence lifetime measured at 700 nm increases from 12 μs for the unoxidized film to 43 μs for the film that was oxidized for 29 min. © 1998 American Institute of Physics.
Show PACS
78.66.Nk Insulators
78.55.Hx Other solid inorganic materials
81.07.-b Nanoscale materials and structures: fabrication and characterization
81.65.Mq Oxidation
61.72.Cc Kinetics of defect formation and annealing
61.85.+p Channeling phenomena (blocking, energy loss, etc.)
71.35.-y Excitons and related phenomena

Secondary electron emission patterning of diamond with hydrogen and oxygen plasmas

Minseo Park, W. B. Choi, S. K. Streiffer, John J. Hren, and Jerome J. Cuomo

Appl. Phys. Lett. 72, 2580 (1998); http://dx.doi.org/10.1063/1.121424 (3 pages) | Cited 4 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Secondary electron emission patterning of single crystal diamond surfaces with hydrogen and oxygen plasma treatments was demonstrated. Hydrogen plasma treated regions were much brighter than the oxygen terminated regions. Results of atomic force microscopy confirmed that the observed contrast is not topographical. Several other possible negative electron affinity (or low positive electron affinity) materials such as chemical vapor deposited (CVD) diamond, aluminum nitride, and tetrahedrally bonded amorphous carbon (txa−C1−x) were also investigated. Faint image contrast (patterning) was also observed from polycrystalline CVD diamond and polycrystalline aluminum nitride films; however, no contrast at all was obtained from tetrahedrally bonded amorphous carbon (txa−C1−x) films. © 1998 American Institute of Physics.
Show PACS
79.20.Hx Electron impact: secondary emission
68.35.B- Structure of clean surfaces (and surface reconstruction)
81.65.Cf Surface cleaning, etching, patterning
68.55.-a Thin film structure and morphology

Impact of ultraviolet light during rapid thermal diffusion

S. Noël, L. Ventura, A. Slaoui, J. C. Muller, B. Groh, R. Schindler, B. Fröschle, and T. Theiler

Appl. Phys. Lett. 72, 2583 (1998); http://dx.doi.org/10.1063/1.121425 (3 pages) | Cited 5 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Rapid thermal processing for junction formation is emerging as a low cost technique for solar cell as well as for other semiconductor device production. Compared to conventional furnace processing, process differences are not only in very high heating and cooling rates, but also in the incoherent emitted radiation spectrum, which can act on dopant diffusion. The photons emitted from tungsten halogen lamps go from far ultraviolet, over visible to infrared light. In this work additional mercury ultraviolet lamps are used during rapid thermal annealing to analyze the influence of high energetic photons on diffusion mechanisms. The diffusion results are discussed in terms of radiation spectrum, involving analysis of diffusion profiles and sheet resistances. © 1998 American Institute of Physics.
Show PACS
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
61.72.S- Impurities in crystals
66.30.J- Diffusion of impurities
81.65.-b Surface treatments
61.72.Cc Kinetics of defect formation and annealing
84.60.Jt Photoelectric conversion

Abnormal photocurrent–voltage behavior of GaAs/AlGaAs multiple shallow quantum well p-i-n diodes

O-Kyun Kwon, Kyu-Seok Lee, Hye Yong Chu, El-Hang Lee, and Byung-Tae Ahn

Appl. Phys. Lett. 72, 2586 (1998); http://dx.doi.org/10.1063/1.120626 (3 pages) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have observed the abnormal photocurrent–voltage (I–V) behavior in GaAs/AlGaAs multiple shallow quantum wells p-i-n diodes. Under the illumination of a laser, two current plateaus were developed at the negative conductance region of the I–V curve, along with some hystereses depending on the scan direction. At the first plateau, two major oscillations of ∼ 120 kHz and ∼ 37 MHz were observed with several minor oscillations of frequencies below the latter, while this latter component was uniquely at the other plateau. Analyzing the electrical and the optical oscillations, we explain that one hysteresis at the first plateau was due to the low frequency bias-circuit oscillations, whereas the other at the next plateau was attributed to the intrinsic behavior of the p-i-n diode. © 1998 American Institute of Physics.
Show PACS
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
85.60.Dw Photodiodes; phototransistors; photoresistors
73.50.Pz Photoconduction and photovoltaic effects
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
73.61.Ey III-V semiconductors
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)

Raman scattering in ion-implanted GaN

W. Limmer, W. Ritter, R. Sauer, B. Mensching, C. Liu, and B. Rauschenbach

Appl. Phys. Lett. 72, 2589 (1998); http://dx.doi.org/10.1063/1.121426 (3 pages) | Cited 83 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Raman measurements were performed on molecular beam epitaxially grown GaN before and after implantation with Ar+, Mg+, P+, C+, and Ca+ ions. With increasing ion dose, new Raman peaks arise at 300, 360, 420, and 670 cm−1, independent of the ion species. After rapid thermal annealing at temperatures between 900 and 1150 °C for 15 s, the intensities of the Raman modes decrease with increasing temperature with the exception of the 360 cm−1 mode which shows a maximum in intensity after annealing at 900 °C. The mode at 300 cm−1 is attributed to disorder-activated Raman scattering, whereas the other three modes are assigned to local vibrations of vacancy-related defects. © 1998 American Institute of Physics.
Show PACS
78.30.Fs III-V and II-VI semiconductors
61.72.Cc Kinetics of defect formation and annealing
61.72.uj III-V and II-VI semiconductors
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
61.72.J- Point defects and defect clusters
63.20.Pw Localized modes

Creation of [110]-aligned Si quantum wires encompassed by SiO2 using low-energy separation-by-implanted-oxygen on a V-groove patterned substrate

Yukari Ishikawa, N. Shibata, and S. Fukatsu

Appl. Phys. Lett. 72, 2592 (1998); http://dx.doi.org/10.1063/1.121427 (3 pages) | Cited 2 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Si quantum wires (QWRs) suspended in SiO2 are successfully created on a V-groove patterned Si(001) substrate by using low-energy oxygen ion implantation. A single Si QWR aligned to [110] is formed near the bottom center of the V groove, which has a hexagonal cross section with {111} and {001} lateral facets. The development of Si QWRs was found to be controlled by the oxygen ion dose and the formation mechanism is attributed to an oxygen ion enrichment near the V-groove corner which arises from lateral ion straggling. © 1998 American Institute of Physics.
Show PACS
85.40.Ry Impurity doping, diffusion and ion implantation technology
61.72.uf Ge and Si
81.05.Cy Elemental semiconductors
81.07.-b Nanoscale materials and structures: fabrication and characterization
81.16.-c Methods of micro- and nanofabrication and processing
85.35.-p Nanoelectronic 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.)
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)

Optical characterization of disordered InxGa1−xP alloys

Luisa González, Yolanda González, Maria Luisa Dotor, and Juan Martinez-Pastor

Appl. Phys. Lett. 72, 2595 (1998); http://dx.doi.org/10.1063/1.121428 (3 pages) | Cited 4 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present results on the optical characterization of InxGa1−xP layers grown by atomic layer molecular beam epitaxy on GaAs (001) substrates at a growth temperature of 420 °C. Our results show that the optical characteristics of these layers, which do not show ordering effects, are strongly dependent on surface stoichiometry during growth. In this way, we can obtain either highly homogeneous alloys with a predictable band-gap energy or layers with optical properties indicative of spatial localization effects, like an anomalous behavior of photoluminescence peak energy with temperature and a large shift between the emission energy and absorption edge. © 1998 American Institute of Physics.
Show PACS
78.66.Jg Amorphous semiconductors; glasses
78.66.Fd III-V semiconductors
78.35.+c Brillouin and Rayleigh scattering; other light scattering
78.30.Fs III-V and II-VI semiconductors
78.55.Cr III-V semiconductors

Growth of InGaAs multi-quantum wells at 1.3 μm wavelength on GaAs compliant substrates

Z. H. Zhu, R. Zhou, F. E. Ejeckam, Z. Zhang, J. Zhang, J. Greenberg, Y. H. Lo, H. Q. Hou, and B. E. Hammons

Appl. Phys. Lett. 72, 2598 (1998); http://dx.doi.org/10.1063/1.121429 (3 pages) | Cited 20 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
InGaAs multiple quantum wells at 1.3 μm wavelength have been grown on a twist-bonded GaAs compliant substrate. The GaAs compliant substrate contains a 30 Å GaAs thin layer bonded to a GaAs bulk substrate with a 22-degree angle. Nomarski phase contrast microscopy, transmission electron microscopy (TEM), and photoluminescence were used to characterize the heteroepitaxial layers. The smooth and crosshatch-free surface morphology, dislocation-free cross-sectional TEM, and strong luminescence intensity all provide convincing evidences for substantial improvement of the quality of heteroepitaxial material using the compliant substrate technique. Research is underway to apply the concept and technique of compliant substrate to Si and other materials. © 1998 American Institute of Physics.
Show PACS
81.05.Ea III-V semiconductors
81.15.Kk Vapor phase epitaxy; growth from vapor phase
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
78.66.Fd III-V semiconductors
78.55.Cr III-V semiconductors
68.35.B- Structure of clean surfaces (and surface reconstruction)

Magnetotransport of delta-doped In0.57Ga0.43As on InP(001) grown between 390 and 575° C by molecular beam epitaxy

Matthew Zervos, Adam Bryant, Martin Elliott, Mathias Beck, and Marc Ilegems

Appl. Phys. Lett. 72, 2601 (1998); http://dx.doi.org/10.1063/1.121430 (3 pages) | Cited 8 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Silicon (Si) delta- (δ-) doped In0.53Ga0.47As layers were grown by molecular beam epitaxy on InP(001) substrates between 390 °C and 575 °C. Subbands formed at the δ layer were examined with Hall and Shubnikov-de Haas effect measurements in conjunction with self-consistent Poisson-Schrödinger modeling. Below a growth temperature of 525 °C we find good agreement with modeling, but above 525 °C a decrease in active doping level suggests possible surface aggregation, or reaction with impurities in the growth chamber. Significant surface segregation spread of the Si is only found for growth above 450 °C. There is some evidence that DX-like centers may be present, since their incorporation improves slightly the quality of the fits to subband occupancies. Samples grown at 390 °C show strong persistent photoconductivity at low temperatures, attributed to defect states in the InGaAs. © 1998 American Institute of Physics.
Show PACS
73.61.Ey III-V semiconductors
81.05.Ea III-V semiconductors
61.72.uj III-V and II-VI semiconductors
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
85.40.Ry Impurity doping, diffusion and ion implantation technology
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
73.50.Pz Photoconduction and photovoltaic effects
61.72.S- Impurities in crystals
71.55.Eq III-V semiconductors

Photoluminescence nonlinearities in mixed type I–type II quantum well heterostructures

E. Finkman and R. Planel

Appl. Phys. Lett. 72, 2604 (1998); http://dx.doi.org/10.1063/1.121431 (3 pages)

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on nonlinear behavior of the intensities and the energies of photoluminescence lines in mixed type I–type II quantum well heterostructures. The structures under study consist of a single enlarged quantum well (SQW), embedded in type II short period superlattices (SPS) on both sides. The nonlinearities are interpreted considering a coupling between the electron levels in the SPS and the SQW, and a very efficient transfer of electrons from the whole structure to the well. The electron density in the SQW as well as the internal electric fields can be optically controlled to high values depending on input power intensities. The nonlinear effects, and the extension of light emission to higher energies in such structures, compared to traditional type I systems, may be of interest in potential applications. © 1998 American Institute of Physics.
Show PACS
78.55.Cr III-V semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
78.66.Fd III-V semiconductors
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
back to top
RSS Feeds

Local disorder effects on the pressure dependence of the metal–insulator transition in manganese perovskites

J. Fontcuberta, V. Laukhin, and X. Obradors

Appl. Phys. Lett. 72, 2607 (1998); http://dx.doi.org/10.1063/1.121432 (3 pages) | Cited 35 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We address the role of the local disorder created by substitutional ions in L2/3A1/3MnO3 oxides, on the pressure dependence of the Curie temperature dln TC/dP. A number of manganites having distinct averaged lanthanide R0 radii and size variance σ2 have been prepared and their resistivity measured up to 11 kbar. It is found that the measured dln TC/dP is mainly determined by R0. However, materials having larger local disorder display larger pressure sensitivity. It is proposed that this results from partial suppression of the local disorder under pressure, and a model is developed to account for the experimental data. © 1998 American Institute of Physics.
Show PACS
75.50.Dd Nonmetallic ferromagnetic materials
71.30.+h Metal-insulator transitions and other electronic transitions
72.60.+g Mixed conductivity and conductivity transitions
75.47.De Giant magnetoresistance
61.66.Fn Inorganic compounds
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)
72.20.My Galvanomagnetic and other magnetotransport effects
62.50.-p High-pressure effects in solids and liquids
back to top
RSS Feeds

Coulomb effects on charged, buried metal disks at room temperature

L.-E. Wernersson, A. Litwin, L. Montelius, H. Pettersson, and L. Samuelson

Appl. Phys. Lett. 72, 2610 (1998); http://dx.doi.org/10.1063/1.121433 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Capacitance transients caused by capture and emission of electrons from buried metal disks are investigated. A single layer of tungsten disks, arranged in a square lattice, is introduced into GaAs by epitaxial overgrowth and a depleted layer is formed around the disks due to the metal–semiconductor Schottky barrier. The number of captured electrons on each disk is measured by the capacitance associated with the width of the depletion layer, whereas the capacitance transients reflect the changes in the number of excess electrons on the disks. By investigating the emission time constants for varying numbers of electrons in excess on the disks, the Coulomb effect is studied. In combination with a temperature-dependent capture, a Coulomb charging energy of only 4 meV is shown to shift the measured activation energies erroneously by hundreds of meV. © 1998 American Institute of Physics.
Show PACS
73.23.Hk Coulomb blockade; single-electron tunneling
73.40.Ns Metal-nonmetal contacts
73.30.+y Surface double layers, Schottky barriers, and work functions

Energy dissipation in tapping-mode atomic force microscopy

J. P. Cleveland, B. Anczykowski, A. E. Schmid, and V. B. Elings

Appl. Phys. Lett. 72, 2613 (1998); http://dx.doi.org/10.1063/1.121434 (3 pages) | Cited 279 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A method is presented to measure the energy dissipated by the tip–sample interaction in tapping-mode atomic force microscopy (AFM). The results show that if the amplitude of the cantilever is held constant, the sine of the phase angle of the driven vibration is then proportional to changes in the tip–sample energy dissipation. This means that images of the cantilever phase in tapping-mode AFM are closely related to maps of dissipation. The maximum dissipation observed for a 4 N/m cantilever with an initial amplitude of 25 nm tapping on a hard substrate at 74 kHz is about 0.3 pW. © 1998 American Institute of Physics.
Show PACS
07.79.Lh Atomic force microscopes

Area-selective nucleation of copper on fluorocarbon–resin surface using ArF excimer laser-induced chemical modification

M. Okoshi and M. Murahara

Appl. Phys. Lett. 72, 2616 (1998); http://dx.doi.org/10.1063/1.121435 (3 pages) | Cited 7 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Area-selective nucleation of copper onto fluorocarbon–resin surface was demonstrated by using an ArF excimer laser and copper–sulfate (CuSO4) aqueous solution. Pyramid-typed shaped nuclei of copper were initially formed on even an inert surface of fluorocarbon–resin in the same way as semiconductor or metal surfaces. Interface of copper nuclei and fluorocarbon–resin was chemically bonded through oxygen which was photodissociated from water in copper–sulfate aqueous solution under ArF excimer laser irradiation. The modification cannot be successful without our previous defluorination efforts using ArF excimer laser-induced chemical reaction. © 1998 American Institute of Physics.
Show PACS
68.55.-a Thin film structure and morphology
81.15.Fg Pulsed laser ablation deposition
79.20.Ds Laser-beam impact phenomena
Page 2 of 2 Pages Previous Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close