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 Feb 1993

Volume 62, Issue 7, pp. 663-788

Page 1 of 2 Pages Next Page | Jump to Page

1.3 μm decoupled confinement heterostructure lasers grown by chemical beam epitaxy

Stefan Hausser, Christoph S. Harder, Heinz P. Meier, and Willi Walter

Appl. Phys. Lett. 62, 663 (1993); http://dx.doi.org/10.1063/1.108858 (3 pages) | Cited 6 times

Full Text: | Download PDF

Show Abstract
A novel 1.3 μm quantum well laser structure, the decoupled confinement heterostructure (DCH) laser is presented. This laser has, at the same time, deep quantum wells and low band‐gap confinement layers, which leads to high optical confinement. Internal barriers prevent carriers from leaking into the confinement layers. We compare results obtained on DCH and conventional 1.3 μm quantum well lasers grown by chemical beam epitaxy (CBE). The DCH lasers have a transparency current density as low as 140 A/cm2, internal optical losses of only 5 cm−1 and their temperature performance has been improved over that of conventional quantum well lasers. Measurements of the spontaneous emission of these lasers clearly show the reduction of carrier leakage at higher temperatures.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.-v Laser optical systems: design and operation

Directed beam emission from film edge in organic electroluminescent diode

Masahiro Hiramoto, Jun‐ichi Tani, and Masaaki Yokoyama

Appl. Phys. Lett. 62, 666 (1993); http://dx.doi.org/10.1063/1.108859 (3 pages) | Cited 13 times

Full Text: | Download PDF

Show Abstract
Narrow beamed light emission was successfully obtained in a new type of organic electroluminescent (EL) diode whose organic layer was sandwiched between two metal layers acting as charge injecting electrodes and mirrors. EL from the organic film edge showed much sharper spectrum with a peak depending on the thickness of the organic layer and about 100 times larger emission density compared with that from the film surface of a conventional EL diode.
Show PACS
85.60.Jb Light-emitting devices
78.60.Fi Electroluminescence
78.66.Qn Polymers; organic compounds

Multihundred‐watt CO laser power delivery through chalcogenide glass fibers

Shunichi Sato, Kaoru Igarashi, Manabu Taniwaki, Kenichi Tanimoto, and Yutaka Kikuchi

Appl. Phys. Lett. 62, 669 (1993); http://dx.doi.org/10.1063/1.108834 (3 pages) | Cited 6 times

Full Text: | Download PDF

Show Abstract
Power transmission characteristics for the 5‐μm band CO laser through chalcogenide glass fibers have been measured. With 1000‐μm core diameter, 1‐m‐long, As‐S and Ge‐As‐S glass fibers, the maximum transmitted powers have reached as high as 226 and 180 W, respectively. By applying antireflection coatings to the fibers, drastic increases in transmission efficiency have been demonstrated.
Show PACS
42.81.Cn Fiber testing and measurement of fiber parameters
42.55.Lt Gas lasers including excimer and metal-vapor lasers
42.62.-b Laser applications

Generation of 415.9–482.6 nm tunable intense picosecond single pulse in LiB3O5

Fang Huang, Liu Huang, Bao‐lu Yin, and You‐nian Hua

Appl. Phys. Lett. 62, 672 (1993); http://dx.doi.org/10.1063/1.108835 (3 pages) | Cited 6 times

Full Text: | Download PDF

Show Abstract
An intelligent type II noncritically phase‐matched LiB3O5 optical generator pumped by 30 ps 355 nm laser pulse is reported. Tunable wavelengths of 482.6–415.9 nm (21–450 °C) with linewidths as low as 0.15 nm, a pump‐to‐signal energy conversion efficiency up to 37.6%, and 211 MW peak‐power single pulse have been achieved.
Show PACS
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
42.65.Re Ultrafast processes; optical pulse generation and pulse compression

Negative and positive ions from CF4 and CF4/O2 rf discharges in etching Si

Yun Lin and Lawrence J. Overzet

Appl. Phys. Lett. 62, 675 (1993); http://dx.doi.org/10.1063/1.108836 (3 pages) | Cited 13 times

Full Text: | Download PDF

Show Abstract
The mass spectra of positive ions and negative ions from CF4 and CF4/O2 rf discharges with and without an etching silicon wafer are presented. The positive ion spectra are largely consistent with those obtained by prior investigations and do not exhibit large changes with the addition of silicon to the discharge. Only one silicon containing positive ion was found, SiF3+ at 85 amu. The negative ion spectra changes considerably with the addition of silicon to the discharge indicating that many of the silicon etching products tend to form negative ions rather than positive ions (or neutral species). In particular, the signal from SiF5− at 123 amu is very large, even larger than the signal of F− at 19 amu when silicon is present. (SiOF3−, SiOF4−, and Si2O2F5− can also have large signal intensities.) While atomic and molecular fluorine are difficult to detect in the positive ion spectra, they are both easily found as negative ions. Some of the relationships between the negative ion signals are consistent with the reactions proposed by C. J. Mogab, A. C. Adams, and D. L. Flamm, J. Appl. Phys. 49, 3796 (1978) and G. Smolinsky and D. L. Flamm, J. Appl. Phys. 50, 4982 (1979).  
Show PACS
52.80.-s Electric discharges
52.25.-b Plasma properties
81.65.-b Surface treatments

Electron velocity distribution function in a gas in E×B fields

Naohiko Shimura and Toshiaki Makabe

Appl. Phys. Lett. 62, 678 (1993); http://dx.doi.org/10.1063/1.108837 (3 pages) | Cited 9 times

Full Text: | Download PDF

Show Abstract
We have investigated the velocity distribution function of electrons in uniform E×B fields by direct numerical analysis of the Boltzmann equation by using the finite element method. The influence of E×B fields on the distribution has been exhibited under the detailed consideration of collisions between electrons and Ar atoms in terms of the three‐dimensional velocity distribution. In particular, the anisotropy of the distribution in the E×B direction is discussed in terms of swarm parameters. The onset behavior of electron trapping has been investigated as a function of B in a collision dominated swarm.
Show PACS
52.20.Fs Electron collisions
52.25.Fi Transport properties
52.65.-y Plasma simulation
85.40.Hp Lithography, masks and pattern transfer

Fabrication of aluminum oxide thin films by a low‐pressure metalorganic chemical vapor deposition technique

J. S. Kim, H. A. Marzouk, P. J. Reucroft, J. D. Robertson, and C. E. Hamrin

Appl. Phys. Lett. 62, 681 (1993); http://dx.doi.org/10.1063/1.108838 (3 pages) | Cited 20 times

Full Text: | Download PDF

Show Abstract
Amorphous Al2O3 thin films were grown on Si(100) and glass substrates by low‐pressure metalorganic chemical vapor deposition using aluminum acetylacetonate and water vapor as source materials. Water vapor played an important role in the oxidation process and produced carbon‐free, pure Al2O3 films. The deposition temperature could be lowered to 230 °C. The films were characterized by means of x‐ray diffraction, x‐ray photoelectron spectroscopy, Auger electron spectroscopy, Rutherford backscattering spectrometry, and ellipsometry.
Show PACS
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Direct evidence for substitutional Li after ion‐implantation into highly phosphorus‐doped Si

U. Wahl, H. Hofsäss, S. G. Jahn, S. Winter, and E. Recknagel

Appl. Phys. Lett. 62, 684 (1993); http://dx.doi.org/10.1063/1.108839 (3 pages) | Cited 4 times

Full Text: | Download PDF

Show Abstract
Radioactive 8Li (t1/2=0.8 s) was ion implanted into single‐crystalline n‐Si of low resistivity (9×1019 P cm−3) at temperatures between 50 and 670 K. Channeling measurements of the alpha‐particles emitted during the decay of 8Li gave direct evidence that 35% of the implanted Li occupied substitutional sites between 350 and 670 K. Below room temperature the major fraction of Li was found to be on tetrahedral sites. The increase in the substitutional fraction around room temperature is attributed to diffusion of Li and capture by vacancy‐related defects.
Show PACS
61.72.uf Ge and Si
61.72.Yx Interaction between different crystal defects; gettering effect
66.30.J- Diffusion of impurities

X‐ray and Raman scattering characterization of Ge/Si buried layers

R. L. Headrick, J.‐M. Baribeau, D. J. Lockwood, T. E. Jackman, and M. J. Bedzyk

Appl. Phys. Lett. 62, 687 (1993); http://dx.doi.org/10.1063/1.108840 (3 pages) | Cited 13 times

Full Text: | Download PDF

Show Abstract
Germanium buried layers in (001) oriented silicon with thicknesses of 2–12 monolayers have been studied with synchrotron x‐ray diffraction, x‐ray reflectivity, and Raman scattering spectroscopy of visible light. Relaxation, strain, and intermixing have been observed via diffraction and intermixing is inferred from vibrational frequency shifts.
Show PACS
68.55.-a Thin film structure and morphology
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties

X‐ray diffraction method for characterization of thin surface layers and thin epitaxial films

Nobuo Itoh

Appl. Phys. Lett. 62, 690 (1993); http://dx.doi.org/10.1063/1.108841 (3 pages) | Cited 4 times

Full Text: | Download PDF

Show Abstract
A new convenient diffraction technique is proposed, which enables us to infer a depth distribution of crystalline quality in a thin crystal layer. When a crystal plate is laid on the side and its reflecting planes get arranged in the vertical with tilting of the surface by a given angle, x‐ray diffraction from the thin surface layer can be obtained. Since glancing angles of x‐ray beams are changed with turning of the crystal by an angle around the diffraction vector and thereby the x‐ray penetration depth is changeable, the depth distribution can be measured. The applicability to characterization of surface damage layers of GaAs crystals and a thin InGaP epitaxial film on a GaAs substrate is demonstrated.
Show PACS
61.05.cf X-ray scattering (including small-angle scattering)
61.05.cj X-ray absorption spectroscopy: EXAFS, NEXAFS, XANES, etc.
68.35.Dv Composition, segregation; defects and impurities
68.55.-a Thin film structure and morphology

Dislocations and strain relief in compositionally graded layers

J. Tersoff

Appl. Phys. Lett. 62, 693 (1993); http://dx.doi.org/10.1063/1.108842 (3 pages) | Cited 121 times

Full Text: | Download PDF


See Also: Erratum

Show Abstract
The performance of strained‐layer heterostructures is often limited by threading dislocations. Such defects can be reduced, and in some cases nearly eliminated, by growing a graded buffer layer. Here, we provide a quantitative picture of the role of grading, by calculating the equilibrium distribution of dislocations and residual strain in such compositionally graded films. In layers with graded strain, threading dislocations are subject to greater force and weaker pinning than in uniform layers, helping them to be swept to the edge of the sample.
Show PACS
68.55.-a Thin film structure and morphology
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
61.72.Lk Linear defects: dislocations, disclinations

Residual strains in epitaxial fluorides on Si(111) substrates

Leo J. Schowalter and Weidan Li

Appl. Phys. Lett. 62, 696 (1993); http://dx.doi.org/10.1063/1.108843 (3 pages) | Cited 4 times

Full Text: | Download PDF

Show Abstract
Growth conditions for molecular beam epitaxy of SrF2 directly on Si(111) have been optimized for excellent crystal quality. A χmin of 2.6% was demonstrated. Lattice distortion measurements were carried out by ion channeling along off‐normal channeling directions in the strained SrF2 layers. The measured residual tensile strain versus the film thickness demonstrated a special thickness: When films were thinner than this thickness, their strain dropped dramatically as thickness decreased, and when films were grown thicker than it, the strain gradually decreased with increasing film thickness. This unique behavior was successfully modeled as the result of competition between the large lattice mismatch between SrF2 and Si and the large difference in thermal coefficients of expansion. Residual strain remained even in SrF2 films thicker than 600 nm, unlike CaF2 on Si(111) for which CaF2 films thicker than 300 nm were observed to have no strain.
Show PACS
68.55.-a Thin film structure and morphology
68.60.Wm Other nonelectronic physical properties

Catalytic effect of phosphine on the deposition of phosphosilicate glass from tetraethoxysilane

Laura L. Tedder, John E. Crowell, Kevin J. Uram, John K. Shugrue, and D. Tribula

Appl. Phys. Lett. 62, 699 (1993); http://dx.doi.org/10.1063/1.108844 (3 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
The effect of phosphorous incorporation on the deposition rate of phosphosilicate glass from the reaction of PH3, O2, and tetraethoxysilane (TEOS) has been studied. The previously reported apparent catalytic effect of PH3 on the deposition rate of SiO2 has been reproduced in this study, but by utilizing a newly designed hot‐walled low‐pressure chemical vapor deposition (LPCVD) reactor, homo‐ and heterogeneous catalytic effects were separated. These results indicate that the source of the catalytic effect is purely homogeneous, possibly involving an oxidation product of PH3 reacting with TEOS. Results obtained in a cold‐wall reactor suggest that PH3 and O2 serve to poison the surface decomposition reaction of TEOS to produce SiO2.
Show PACS
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
82.30.-b Specific chemical reactions; reaction mechanisms
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces

GaN grown on hydrogen plasma cleaned 6H‐SiC substrates

M. E. Lin, S. Strite, A. Agarwal, A. Salvador, G. L. Zhou, N. Teraguchi, A. Rockett, and H. Morkoç

Appl. Phys. Lett. 62, 702 (1993); http://dx.doi.org/10.1063/1.108845 (3 pages) | Cited 91 times

Full Text: | Download PDF

Show Abstract
We report epitaxial GaN layers grown on 6H‐SiC (0001) substrates. A two stage substrate preparation procedure is described which effectively removes oxygen from the SiC substrate surface without the need of elaborate high temperature processing. In the first step, dangling Si bonds on the substrate surface are hydrogen passivated using a HF dip before introduction into vacuum. Second, the substrate is treated with a hydrogen plasma reducing the amount of oxygen‐carbon bonding to below the x‐ray photoemission detection limit. Upon heating in the molecular beam epitaxy (MBE) growth chamber, the SiC substrates are observed to have a sharp (1×1) reconstruction with Kikuchi lines readily visible. GaN epilayers deposited on AlN buffer layers by plasma enhanced MBE show sharp x‐ray diffraction and photoluminescence peaks.
Show PACS
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
81.65.-b Surface treatments

Transport properties of indium tin oxide/p‐InP structures

J. K. Luo and H. Thomas

Appl. Phys. Lett. 62, 705 (1993); http://dx.doi.org/10.1063/1.108846 (3 pages) | Cited 10 times

Full Text: | Download PDF

Show Abstract
I‐V properties of indium tin oxide (ITO)/p‐InP solar cell structures measured at various temperatures show that the conduction mechanism is dominated by tunneling at low forward bias, and by thermionic emission at high forward bias. An increase of barrier height of 200–300 meV was found for all ITO/InP diodes compared with Au/InP Schottky diodes. Donorlike defects were found to be responsible for the increase of barrier height, and to cause the defect‐assisted tunneling conduction. The experimental results support the model of a buried n+/p junction with the n+ layer induced by the sputter deposition of ITO.
Show PACS
73.40.-c Electronic transport in interface structures
84.60.Jt Photoelectric conversion

Visible light emission from heavily doped porous silicon homojunction pn diodes

Zhiliang Chen, Gijs Bosman, and Romulo Ochoa

Appl. Phys. Lett. 62, 708 (1993); http://dx.doi.org/10.1063/1.109603 (3 pages) | Cited 41 times

Full Text: | Download PDF

Show Abstract
We observed visible light emission with a peak wavelength of 640 nm from forward biased, heavily doped porous silicon homojunction pn diodes. The light emission is attributed to electron‐hole recombination across the direct band gap of the monocrystalline quantum wires which make up the porous silicon junction layers.
Show PACS
78.60.Fi Electroluminescence
78.66.Li Other semiconductors
73.40.Lq Other semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
85.60.Jb Light-emitting devices

Enhancement of photoluminescence intensity of GaAs with cubic GaS chemical vapor deposited using a structurally designed single‐source precursor

Andrew N. MacInnes, Michael B. Power, Andrew R. Barron, Phillip P. Jenkins, and Aloysius F. Hepp

Appl. Phys. Lett. 62, 711 (1993); http://dx.doi.org/10.1063/1.108847 (3 pages) | Cited 46 times

Full Text: | Download PDF

Show Abstract
A two order‐of‐magnitude enhancement of photoluminescence intensity relative to untreated GaAs has been observed for GaAs surfaces coated with chemical vapor‐deposited GaS. The increase in photoluminescence intensity can be viewed as an effective reduction in surface recombination velocity and/or band bending. The gallium cluster [(t‐Bu)GaS]4 was used as a single‐source precursor for the deposition of GaS thin films. The cubane core of the structurally characterized precursor is retained in the deposited film producing a cubic phase. Furthermore, a near‐epitaxial growth is observed for the GaS passivating layer. Films were characterized by transmission electron microscopy, x‐ray powder diffraction, and x‐ray photoelectron and Rutherford backscattering spectroscopies.
Show PACS
78.55.Cr III-V semiconductors
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths
81.15.Kk Vapor phase epitaxy; growth from vapor phase

Bistable saturation in coupled quantum dots for quantum cellular automata

Craig S. Lent, P. Douglas Tougaw, and Wolfgang Porod

Appl. Phys. Lett. 62, 714 (1993); http://dx.doi.org/10.1063/1.108848 (3 pages) | Cited 104 times

Full Text: | Download PDF

Show Abstract
A simple model quantum dot cell containing two electrons is analyzed as a candidate for quantum cellular automata implementations. The cell has eigenstates whose charge density is strongly aligned along one of two directions. In the presence of the electrostatic perturbation due to a neighboring cell, the ground state is nearly completely aligned (polarized) in one direction only. The polarization is a highly nonlinear function of the perturbing electrostatic fields and shows the strong bistable saturation important for cellular automation function.
Show PACS
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
71.45.Gm Exchange, correlation, dielectric and magnetic response functions, plasmons
85.30.De Semiconductor-device characterization, design, and modeling

Photoluminescence from ultrathin ZnSe/CdSe quantum wells

H. Zajicek, P. Juza, E. Abramof, O. Pankratov, H. Sitter, M. Helm, G. Brunthaler, W. Faschinger, and K. Lischka

Appl. Phys. Lett. 62, 717 (1993); http://dx.doi.org/10.1063/1.109615 (3 pages) | Cited 20 times

Full Text: | Download PDF

Show Abstract
Self‐limiting monolayer epitaxy has been used to prepare ZnSe/CdSe quantum well structures containing 1–5 monolayers (≊3–15 Å) thick CdSe quantum wells. Photoluminescence spectra of these structures show bright excitonic lines with a blue shift of maximum 870 meV for the 1 monolayer wide quantum wells. Calculations for the energetic positions of the photoluminescence peaks are in good agreement with the experimental data. The full width at half maximum of the photoluminescence lines increases from about 25 meV for the 1 ML quantum wells to about 75 meV for the 3 ML quantum wells.
Show PACS
78.66.Hf II-VI semiconductors
78.55.Et II-VI semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Carrier‐dependent hydrogen migration in hydrogenated amorphous silicon

Paulo V. Santos and N. M. Johnson

Appl. Phys. Lett. 62, 720 (1993); http://dx.doi.org/10.1063/1.108849 (3 pages) | Cited 12 times

Full Text: | Download PDF

Show Abstract
Experiments demonstrate that hydrogen migration in hydrogenated amorphous silicon is controlled by the concentration of electronic carriers and, therefore, is strongly suppressed when the carriers are removed by an electric field. Furthermore, the few hydrogen atoms migrating in a region depleted of carriers have an increased mean free path for diffusion due to a reduction in the concentration of trapping centers, which are probably silicon dangling bonds.
Show PACS
66.30.-h Diffusion in solids
61.43.Dq Amorphous semiconductors, metals, and alloys

Effects of drift and diffusion current flow on the high‐speed performance of quantum well lasers

G. W. Taylor and P. R. Claisse

Appl. Phys. Lett. 62, 723 (1993); http://dx.doi.org/10.1063/1.108850 (3 pages) | Cited 4 times

Full Text: | Download PDF

Show Abstract
A new approach is described to incorporate the effects of drift and diffusion into the small signal transfer function of the quantum well semiconductor laser. The differential gain parameter is represented by the differential stimulated lifetime and is a constant, power‐independent parameter. The nonlinear gain factor is not required in the analysis with the saturation of the resonant frequency resulting instead from the effects of diffusion current flow through the active layer. The electron and photon rate equations used are interrelated by the Fermi energy as a parametric variable.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Uniformity of GexSi1−x epitaxial layers grown by ultrahigh vacuum chemical‐vapor deposition

D. W. Greve, G. McLaughlin, M. A. Capano, and M. Racanelli

Appl. Phys. Lett. 62, 726 (1993); http://dx.doi.org/10.1063/1.108851 (3 pages) | Cited 3 times

Full Text: | Download PDF

Show Abstract
We report on the uniformity of composition and thickness of epitaxial GexSi1−x layers grown by ultrahigh vacuum chemical‐vapor deposition. Double‐crystal x‐ray diffractometry showed that variations in thickness are less than ±2.2% and variations in composition less than ±2.5% from center to edge of a 75 mm wafer. The variations observed are consistent with the predictions of Monte Carlo simulations.
Show PACS
68.55.-a Thin film structure and morphology
81.15.Kk Vapor phase epitaxy; growth from vapor phase

Strained GaxIn1−xP multiple quantum wire light‐emitting diodes: A luminescence polarization study

P. J. Pearah, E. M. Stellini, A. C. Chen, A. M. Moy, K. C. Hsieh, and K. Y. Cheng

Appl. Phys. Lett. 62, 729 (1993); http://dx.doi.org/10.1063/1.108852 (3 pages) | Cited 19 times

Full Text: | Download PDF

Show Abstract
Strongly polarized photoluminescence and electroluminescence spectra have been obtained from strained GaxIn1−xP quantum wire heterostructures grown on (100) oriented, on‐axis GaAs substrates by an in situ epitaxial technique. The phenomenon of strain‐induced lateral layer ordering has been exploited in order to create lateral superlattices of GaxIn1−xP compositionally modulated in the [110] direction with a modulation period of 96 Å. The previous and subsequent growth of lattice‐matched Ga0.51In0.49P ternary alloy epilayers results in the formation of compressively strained quantum wires. Transmission electron microscopy shows the wire cross sections to be ∼48×200 Å. These structures exhibit 77 K photoluminescence spectra at 1.79 eV that are strongly (96%) polarized parallel to the wires due to strain resulting from the lateral compositional modulation. The intensity of this emission depends critically on the polarization of the incident excitation. Electroluminescence spectra from multiple quantum wire light‐emitting diodes display anisotropic polarization as well. The energies and optical anisotropies of these luminescence bands are consistent with a simple theoretical analysis.  
Show PACS
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
78.66.Fd III-V semiconductors
78.60.Fi Electroluminescence

Time‐resolved luminescence study of ultrafast carrier transport in GaAs metal‐semiconductor‐metal devices

R. Kersting, J. Plettner, K. Leo, S. Averin, and H. Kurz

Appl. Phys. Lett. 62, 732 (1993); http://dx.doi.org/10.1063/1.108853 (3 pages) | Cited 3 times

Full Text: | Download PDF

Show Abstract
Femtosecond time‐resolved luminescence spectroscopy is used as a novel tool to study the ultrafast transport in interdigitated metal‐semiconductor‐metal Schottky diodes. The time‐resolved luminescence signals of GaAs‐MSM diodes depend strongly on bias voltage and carrier density. In these experiments, field‐induced transfer to indirect valleys is directly observed in the time domain for the first time.
Show PACS
73.40.Sx Metal-semiconductor-metal structures
78.47.-p Spectroscopy of solid state dynamics
85.60.Dw Photodiodes; phototransistors; photoresistors

Hydrogen plasma removal of AlGaAs oxides before molecular beam epitaxy

Kent D. Choquette, M. Hong, S. N. G. Chu, H. S. Luftman, J. P. Mannaerts, R. C. Wetzel, and R. S. Freund

Appl. Phys. Lett. 62, 735 (1993); http://dx.doi.org/10.1063/1.108854 (3 pages) | Cited 8 times

Full Text: | Download PDF

Show Abstract
We report a method for the removal of AlxGa1−xAs native oxides for 0≤x≤1, prior to molecular beam epitaxial overgrowth. The oxides formed on epilayers of AlGaAs after atmospheric exposure are removed in an electron cyclotron resonance hydrogen plasma with a substrate temperature less than 400 °C. Reflection high energy electron diffraction indicates the plasma‐prepared AlGaAs surface are oxide‐free and crystalline; after a vacuum anneal to 250–500 °C, GaAs or AlGaAs are epitaxially overgrown on these surfaces. Secondary ion mass spectroscopy detects C, O, and Si impurities at the interfaces, where their concentrations increase with increasing Al content of the exposed surface. The quality of the interface and the overgrown film, as observed by transmission electron microscopy, are found to be better for lower interface impurity densities.
Show PACS
81.65.-b Surface treatments
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
Page 1 of 2 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close