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

8 Jun 1992

Volume 60, Issue 23, pp. 2825-2938

Page 2 of 2 Pages Previous Page | Jump to Page

Alloy scattering‐limited mobility in narrow quantum wells

Sanghamitra Mukhopadhyay and B. R. Nag

Appl. Phys. Lett. 60, 2897 (1992); http://dx.doi.org/10.1063/1.106812 (3 pages) | Cited 6 times

Full Text: | Download PDF

Show Abstract
Alloy scattering‐limited mobility is calculated for narrow quantum wells of GaAs/Ga0.7Al0.3As, Ga0.47In0.5As/InP, and Al0.48In0.5As/Ga0.47In0.53As systems with widths down to 0.5 nm, taking into account the energy‐band nonparabolicity and the effects of wave‐function penetration into the barrier layer. Values of mobility are found to be significantly different from those given by the formulas derived earlier for wide wells.
Show PACS
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths
72.10.Bg General formulation of transport theory

Native donors and acceptors in molecular‐beam epitaxial GaAs grown at 200 °C

D. C. Look, D. C. Walters, M. Mier, C. E. Stutz, and S. K. Brierley

Appl. Phys. Lett. 60, 2900 (1992); http://dx.doi.org/10.1063/1.106813 (3 pages) | Cited 42 times

Full Text: | Download PDF

Show Abstract
Absorption measurements at 1.1 and 1.2 μm were used along with the known electron and hole photoionization cross sections for EL2 to determine deep donor (EL2‐like) and acceptor concentrations ND=9.9×1019 and NA=7.9×1018 cm−3, respectively, in a 2‐μm‐thick molecular‐beam epitaxial GaAs layer grown at 200 °C on a 2‐in.‐diam semi‐insulating wafer. Both lateral and depth uniformities of ND over the wafer were excellent as was also the case for the conductivity. Band conduction was negligible compared to hopping conduction at 296 K as evidenced by the lack of a measurable Hall coefficient.  
Show PACS
71.55.Eq III-V semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
78.30.-j Infrared and Raman spectra
78.40.Fy Semiconductors

Growth of carbon‐doped p‐type InxGa1−xAs (0<x≤0.53) by metalorganic chemical vapor deposition

S. A. Stockman, A. W. Hanson, and G. E. Stillman

Appl. Phys. Lett. 60, 2903 (1992); http://dx.doi.org/10.1063/1.106814 (3 pages) | Cited 32 times

Full Text: | Download PDF

Show Abstract
Carbon doping of InxGa1−xAs grown on GaAs and InP substrates by low‐pressure metalorganic chemical vapor deposition (LP‐MOCVD) using CCl4 has been investigated for In mole fractions as high as x=0.53. P‐type conduction was obtained over the entire composition range studied, with hole concentrations above 1×1020 cm−3 for x<0.12, and as high as 1×1019 cm−3 for In0.53Ga0.47As lattice‐matched to InP. These high carbon concentrations were achieved by employing very low V/III ratios and low growth temperatures. The alloy composition was found to be dependent on several growth parameters, including CCl4 partial pressure, V/III ratio, and growth temperature. This may be due to surface reactions (etching) involving chlorine‐containing compounds during growth. Samples grown at low temperature (∼500 °C) and lattice matched to InP exhibited an increase in hole concentration upon post‐growth annealing.
Show PACS
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
73.61.Ey III-V semiconductors

Low‐frequency oscillations in semi‐insulating InP

C. Backhouse, V. A. Samuilov, and L. Young

Appl. Phys. Lett. 60, 2906 (1992); http://dx.doi.org/10.1063/1.106815 (2 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
Goronkin and Maracas (IEDM Conf. Proc., Dec. 1984, p. 182) reported a method of obtaining information on deep levels in GaAs by analyzing the temperature dependence of low‐frequency current oscillations observed in semi‐insulating material. In the present work, a modified version of their method was applied to Fe compensated InP. Power density spectra showed one main peak and several less well defined. An Arrhenius plot of log(T2/2f) versus 1/T gave an activation energy of 0.47 eV for the main peak, close to the value found by optical transient current spectroscopy (OTCS). The method is complementary to OTCS in that the same equipment is used and information is obtained more easily on levels which exhibit field‐enhanced trapping.
Show PACS
71.55.Eq III-V semiconductors
72.80.Ey III-V and II-VI semiconductors
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping

Self‐consistent scattering matrix calculation of the distribution function in semiconductor devices

Mark A. Stettler and Mark S. Lundstrom

Appl. Phys. Lett. 60, 2908 (1992); http://dx.doi.org/10.1063/1.106816 (3 pages) | Cited 4 times

Full Text: | Download PDF

Show Abstract
The scattering matrix approach is a new technique for solving the Boltzmann equation in devices. We report a self‐consistent application of the technique to realistic silicon devices exhibiting strong nonlocal effects. Simulation of a hot‐electron, n‐i‐n diode demonstrates that the new technique efficiently and accurately reproduces Monte Carlo results without the statistical noise, allowing much tighter convergence with Poisson’s equation.
Show PACS
85.30.De Semiconductor-device characterization, design, and modeling
72.10.Bg General formulation of transport theory
73.50.Fq High-field and nonlinear effects

In incorporation in GaInAs grown by molecular beam epitaxy

Karl Woodbridge

Appl. Phys. Lett. 60, 2911 (1992); http://dx.doi.org/10.1063/1.106817 (3 pages) | Cited 4 times

Full Text: | Download PDF

Show Abstract
A study of In segregation during molecular beam epitaxial growth of GaInAs is reported. We find that In segregates to the surface during growth above approximately 550 °C and a constant surface concentration forms at low In flux. If the In flux is increased, a continuous buildup of In can occur due to the segregation rate not being balanced by the re‐evaporation rate. Up to two monolayers of In may have segregated onto the surface during the growth of 200 Å of Ga0.75In0.25As at 560 °C. The In surface buildup appears to be suppressed by increasing the arsenic to group III flux ratio. A continuing incident Ga flux, after the In flux has been terminated, significantly prolongs the surface recovery time. The implications of these results for the growth of GaAs/GaInAs multiple quantum well layers is discussed.
Show PACS
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.-a Thin film structure and morphology

Investigation on the growth rate enhancement by Ge during SiGe alloy deposition by chemical vapor deposition

Bob M. H. Ning and John E. Crowell

Appl. Phys. Lett. 60, 2914 (1992); http://dx.doi.org/10.1063/1.106818 (3 pages) | Cited 31 times

Full Text: | Download PDF

Show Abstract
The desorption of deuterium from clean and Ge‐covered Si(100) surfaces has been studied using temperature‐programmed desorption. The Ge/Si(100) surfaces were prepared using the dissociative adsorption of digermane on Si(100). The presence of Ge on Si(100) dramatically lowers the deuterium (or hydrogen) desorption temperature. The desorption maxima shift to lower temperature with increasing Ge coverage until a new low‐temperature desorption state becomes dominant. The lowering of the deuterium desorption energies due to the presence of Ge on the Si(100) surface is used to explain the acceleration in growth rate observed during GexSi1−x alloy growth by chemical vapor deposition upon the introduction of germane to the Si source gas.
Show PACS
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.55.-a Thin film structure and morphology
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)

High‐responsivity photoconductive ultraviolet sensors based on insulating single‐crystal GaN epilayers

M. Asif Khan, J. N. Kuznia, D. T. Olson, J. M. Van Hove, M. Blasingame, and L. F. Reitz

Appl. Phys. Lett. 60, 2917 (1992); http://dx.doi.org/10.1063/1.106819 (3 pages) | Cited 172 times

Full Text: | Download PDF

Show Abstract
We report on the fabrication and characterization of photoconductive ultraviolet detectors based on insulating single‐crystal GaN. The active layer (GaN) was deposited over basal‐plane sapphire substrates using a unique switched atomic‐layer‐epitaxy process. The sensors were measured to have a responsivity of 2000 A/W at a wavelength of 365 nm under a 5‐V bias. The responsivity remained nearly constant for wavelengths from 200 to 365 nm and dropped by three orders of magnitude within 10 nm of the band edge (by 375 nm). We estimate our sensors to have a gain of 6×103 (for wavelength 365 nm) and a bandwidth in excess of 2 kHz. The photosignal exhibited a linear behavior over five orders of incident optical power, thereby implying a very large dynamic range for these GaN‐based ultraviolet sensors.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
73.50.Pz Photoconduction and photovoltaic effects
78.40.-q Absorption and reflection spectra: visible and ultraviolet
68.55.-a Thin film structure and morphology

Improvement of the probe profiling method for InP/GaInAsP structures using Kr+ ion bombardment

J. Walachová

Appl. Phys. Lett. 60, 2920 (1992); http://dx.doi.org/10.1063/1.106820 (3 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
An improvement of the resolution of the probe profiling method based on low energy Kr+ ion bombardment of a beveled sample is demonstrated for two multiwell‐barrier structures. The materials used are InP, GaInAsP (λ=1.3 μm) and GaInAsP (λ=1.1 μm). The limit of resolution of the method is discussed.
Show PACS
68.55.-a Thin film structure and morphology
73.40.Cg Contact resistance, contact potential
61.80.Jh Ion radiation effects

Piezoresistivity in vapor‐deposited diamond films

M. Aslam, I. Taher, A. Masood, M. A. Tamor, and T. J. Potter

Appl. Phys. Lett. 60, 2923 (1992); http://dx.doi.org/10.1063/1.106821 (3 pages) | Cited 40 times

Full Text: | Download PDF

Show Abstract
We report the observation of a very large piezoresistive effect in both polycrystalline and homoepitaxial chemical‐vapor‐deposited diamond films. The gauge factor for polycrystalline p‐type diamond at 500 microstrains was found to be only 6 at room ambient, but increased rapidly with temperature, exceeding that of polycrystalline silicon (30) at 35 °C, and that of single‐crystal Si (120) at 50 °C. For strain and current flow in the [100] direction, the gauge factor of a (100)‐oriented homoepitaxial diamond film was found to be at least 550 at room temperature. Although the origins and unexpected temperature dependence of piezoresistive effect in diamond are not yet understood, these findings may suggest diamond‐based sensors with performance significantly superior to that of their Si counterparts.
Show PACS
77.65.-j Piezoelectricity and electromechanical effects
73.50.Dn Low-field transport and mobility; piezoresistance
85.50.-n Dielectric, ferroelectric, and piezoelectric devices

Metalorganic chemical vapor deposition of low microwave surface resistance YBa2Cu3O7 on (100) LaAlO3 and (100) SrTiO3

W. J. DeSisto, R. L. Henry, H. S. Newman, M. S. Osofsky, and V. C. Cestone

Appl. Phys. Lett. 60, 2926 (1992); http://dx.doi.org/10.1063/1.106822 (3 pages) | Cited 8 times

Full Text: | Download PDF

Show Abstract
Thin films of YBa2Cu3O7−δ on (100) LaAlO3 and (100) SrTiO3, up to 5000 Å thick, were grown by metalorganic chemical vapor deposition. The as‐deposited films were c‐axis oriented, and had transition temperatures between 87 and 89 K, transition widths less than or equal to 1 K, and critical current densities of 1–3×106 A/cm2 at 77 K. Microwave surface resistance measurements at 36 GHz on (100) LaAlO3 showed significant improvements over copper metal at 77 K. Films grown on (100) SrTiO3 exhibited slightly better properties than those grown on (100) LaAlO3. Films which were slightly deficient in barium and rich in yttrium consistently demonstrated superior properties.
Show PACS
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
74.78.-w Superconducting films and low-dimensional structures
74.70.-b Superconducting materials other than cuprates

Improvement of flux pinning in the Ag‐clad Bi‐Pb‐Sr‐Ca‐Cu‐O wires through the use of a short period melt processing

S. X. Dou, H. K. Liu, and Y. C. Guo

Appl. Phys. Lett. 60, 2929 (1992); http://dx.doi.org/10.1063/1.106823 (3 pages) | Cited 30 times

Full Text: | Download PDF

Show Abstract
A significant enhancement of the Jc in magnetic field in the Ag‐clad Bi‐Pb‐Sr‐Ca‐Cu‐O (BPSCCO) wires has been achieved by using a short period melt processing. The weak links have been largely eliminated in the melt‐processed tapes which exhibits a 3–10‐fold increase in the Jc at 77 K and 1 T over the normally processed tapes. For tapes with a thickness 80 μm 60% of melt‐processed samples have the Jc values between 10 000 and 27 000 A/cm2 at 77 K in zero field. The irreversibility lines determined using ac susceptibility measurements under dc fields confirmed the improvement of flux pinning in the melt‐processed tapes compared with the normally processed tapes. The improved Jc‐H characteristics may be attributed to the desirable microstructures produced from the high Tc phase formation‐decomposition‐recovery process through the use of a short period melting.
Show PACS
84.71.Ba Superconducting magnets; magnetic levitation devices
81.40.Ef Cold working, work hardening; annealing, post-deformation annealing, quenching, tempering recovery, and crystallization
74.70.-b Superconducting materials other than cuprates
74.25.Uv Vortex phases (includes vortex lattices, vortex liquids, and vortex glasses)

Enhancement of flux pinning by H+ and Xe+ irradiation in epitaxial thin films of Ba2YCu3O7−δ

M. P. Siegal, R. B. van Dover, Julia M. Phillips, E. M. Gyorgy, A. E. White, and J. H. Marshall

Appl. Phys. Lett. 60, 2932 (1992); http://dx.doi.org/10.1063/1.106824 (3 pages) | Cited 17 times

Full Text: | Download PDF

Show Abstract
Epitaxial Ba2YCu3O7−δ (BYCO) films grown by the ex situ BaF2 process are comparable to single crystals both in crystalline quality and the value and temperature dependence of the critical current (Jc) in an applied magnetic field in the BYCO (001) direction of Ha=0.9 T. With the appropriate dose of either 2 MeV H+ or 135Xe+, we can enhance Jc by a factor of 2 in Ha=0.9 T with little effect on Tc. This is significantly greater than the ∼25% enhancement previously reported for epitaxial BYCO films grown by in situ techniques [Roas, Hensel, and Saemann‐Ischenko, Appl. Phys. Lett. 54, 1051 (1989)]. This provides the opportunity to isolate the induced defects and study their properties.
Show PACS
74.25.Uv Vortex phases (includes vortex lattices, vortex liquids, and vortex glasses)
74.70.-b Superconducting materials other than cuprates
74.78.-w Superconducting films and low-dimensional structures
61.80.Jh Ion radiation effects

Nanotips by reverse electrochemical etching

Mircea Fotino

Appl. Phys. Lett. 60, 2935 (1992); http://dx.doi.org/10.1063/1.107468 (3 pages) | Cited 17 times

Full Text: | Download PDF

Show Abstract
A simple, two‐stage procedure is shown to produce slender and ultrasharp tungsten tips of nanometer and subnanometer apex dimensions (nanotips). Tip sharpening is achieved by electrochemical etching through bubble dynamics induced by ac voltage in a novel configuration in which the wire end is oriented upward. Tip shape is characterized by high‐resolution transmission electron microscopy.
Show PACS
07.79.Cz Scanning tunneling microscopes
61.05.-a Techniques for structure determination
81.05.Bx Metals, semimetals, and alloys
82.45.-h Electrochemistry and electrophoresis
FREE

Erratum: ‘‘Quantum wire and dot formation by chemical vapor deposition and molecular layer deposition of one‐dimensional conjugated polymer’’ [Appl. Phys. Lett. 60, 268 (1992)]

Tetsuzo Yoshimura, Satoshi Tatsuura, Wataru Sotoyama, Azuma Matsuura, and Tomoaki Hayano

Appl. Phys. Lett. 60, 2938 (1992); http://dx.doi.org/10.1063/1.107451 (1 page)

Full Text: | Download PDF

Abstract Unavailable
Show PACS
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
99.10.Cd Errata
Page 2 of 2 Pages Previous Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close