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18 Jun 1990

Volume 56, Issue 25, pp. 2487-2586

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Optimization of stripe width for low‐threshold operation of quantum well laser diodes

J. S. Osinski, K. M. Dzurko, S. G. Hummel, and P. D. Dapkus

Appl. Phys. Lett. 56, 2487 (1990); http://dx.doi.org/10.1063/1.102887 (3 pages) | Cited 3 times

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An experimentally verified model for threshold current in GaAs/AlGaAs quantum well laser diodes has been extended to calculate for the first time the dependence of threshold current on stripe width. The lowest possible threshold is shown to occur when the lateral confinement factor is in the range of 55–60% for typical devices, a value that is not affected by mirror reflectivity or lateral index step. A simple, generalized optimization scheme for obtaining the unique width/length combination that results in lowest threshold is presented, and predicts potential as‐cleaved threshold currents as low as 0.5 mA.
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42.55.Px Semiconductor lasers; laser diodes
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.60.By Design of specific laser systems

Optical generation of picosecond electrical pulses in asymmetric quantum well structures placed in a transverse magnetic field

J. Khurgin

Appl. Phys. Lett. 56, 2490 (1990); http://dx.doi.org/10.1063/1.102888 (3 pages)

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New technique for optical generation of ultrashort electrical pulses in semiconductor heterostructures is proposed. It is shown that in asymmetric quantum well structures placed in a transverse magnetic field, optically excited carriers have an asymmetrical distribution in k‐vector space, and therefore, they have finite drift velocity in the direction perpendicular to both growth direction and field direction. It results in photogenerated voltage along the quantum well plane. The temporal response and sensitivity of the proposed scheme are evaluated, and possible applications are suggested in ultrafast detectors or as a tool for generation and study of hot carriers.
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73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
73.50.Fq High-field and nonlinear effects
73.50.Pz Photoconduction and photovoltaic effects
75.80.+q Magnetomechanical effects, magnetostriction

Precision AlGaAs Bragg reflectors fabricated by phase‐locked epitaxy

J. D. Walker, K. Malloy, S. Wang, and J. S. Smith

Appl. Phys. Lett. 56, 2493 (1990); http://dx.doi.org/10.1063/1.102890 (3 pages) | Cited 10 times

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Extremely high quality AlGaAs Bragg reflectors have been fabricated by molecular beam epitaxy using advanced growth techniques including phase‐locked epitaxy, short‐period superlattices, and growth interruptions. These techniques are used to control the layer periodicity, interface flatness, and producibility of the structures. The experimental reflectance spectrum shows an extremely square stop band and very regular side lobes closely matching the theoretical spectrum. A comparison of experimental to theoretical reflectance spectra is used to show that the layer periodicity is maintained within 1% and the interface flatness controls the optical loss per interface to less than 0.1%. Experimental results show a maximum reflectance of 98.5% for a (AlAs)6(GaAs)3/(AlAs)1(GaAs)4 35.5‐period Bragg reflector.
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42.79.Dj Gratings
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Drastic reduction of series resistance in doped semiconductor distributed Bragg reflectors for surface‐emitting lasers

K. Tai, L. Yang, Y. H. Wang, J. D. Wynn, and A. Y. Cho

Appl. Phys. Lett. 56, 2496 (1990); http://dx.doi.org/10.1063/1.102869 (3 pages) | Cited 52 times

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Modifications to reduce the series resistance in p‐type semiconductor distributed Bragg reflectors (DBR) consisting of ten pairs of quarter‐wavelength GaAs (high refractive index)/Al0.7Ga0.3As (low index) layers were made by inserting an intermediate Al0.35Ga0.65As layer or a 200 Å superlattice of GaAs(10 Å)/Al0.7Ga0.3As (10 Å) at the GaAs/Al0.7Ga0.3As heterointerfaces. The specific DBR series resistance was reduced by two orders of magnitude to about 6.2×10−5 Ω cm2. These modifications did not alter the optical reflectivity and nearly identical reflection spectra were measured.
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42.60.Da Resonators, cavities, amplifiers, arrays, and rings
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
78.20.Bh Theory, models, and numerical simulation
74.20.-z Theories and models of superconducting state

Low‐threshold GaAs/AlGaAs graded‐index separate confinement heterostructure lasers grown by molecular beam epitaxy on oxide‐masked Si substrates

Geoffrey F. Burns, Hervé Blanck, and Clifton G. Fonstad

Appl. Phys. Lett. 56, 2499 (1990); http://dx.doi.org/10.1063/1.102870 (3 pages) | Cited 2 times

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Low‐threshold GaAs/AlGaAs lasers have, for the first time, been grown selectively on 10 μm stripe openings patterned in oxide on Si substrates. Lateral current confinement provided by side facets reduces edge leakage, and results in threshold currents as low as 75 mA for a 10 μm by 210 μm device, a nearly two‐fold improvement over comparable etched ridge waveguide lasers. Spectrum measurements show single longitudinal mode emission near 850 nm. This adaptation of selective heteroepitaxial growth for lateral current confinement of AlGaAs/GaAs lasers on Si substrates, adopted from similar work on GaAs substrates, offers potential for significant threshold current reductions of lasers integrable with Si.
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42.55.Px Semiconductor lasers; laser diodes
85.60.Jb Light-emitting devices
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
42.60.By Design of specific laser systems

1.5 μm InGaAsP/InP buried crescent superluminescent diode on a p‐InP substrate

T. R. Chen, Y. H. Zhuang, Y. J. Xu, A. Yariv, and N. S. Kwong

Appl. Phys. Lett. 56, 2502 (1990); http://dx.doi.org/10.1063/1.102871 (2 pages) | Cited 2 times

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An InGaAsP/InP superluminescent diode (SLD) emitting at 1.54 μm has been fabricated. The device uses a buried crescent structure on a p‐InP substrate. The parameters were optimized for high output power, small spectral modulation, and smooth far‐field operation. The coherence function of the SLD emission was studied systematically. An output power of 5 mW, a coherence length of 41 μm, and a second coherence peak suppression ratio of 22 dB were obtained.
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85.60.Jb Light-emitting devices
42.55.Px Semiconductor lasers; laser diodes
42.50.Nn Quantum optical phenomena in absorbing, amplifying, dispersive and conducting media; cooperative phenomena in quantum optical systems
42.81.Wg Other fiber-optical devices

Slow wave propagation in air‐filled porous materials and natural rocks

Peter B. Nagy, Laszlo Adler, and Brian P. Bonner

Appl. Phys. Lett. 56, 2504 (1990); http://dx.doi.org/10.1063/1.102872 (3 pages) | Cited 14 times

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Slow compressional waves in fluid‐saturated porous solids offer a unique acoustical means to study certain material properties, such as tortuosity and permeability. We present a novel experimental technique based on the transmission of airborne ultrasound through air‐filled porous samples. The suggested method can be used to measure the velocity and attenuation of the slow compressional wave in a wide frequency range from 30 to 500 kHz. More important, the technique is so sensitive that it provides irrefutable evidence of slow wave propagation in air‐saturated natural rocks and lends itself quite easily to tortuosity measurements in such materials, too.
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43.35.Yb Ultrasonic instrumentation and measurement techniques
43.35.Cg Ultrasonic velocity, dispersion, scattering, diffraction, and attenuation in solids; elastic constants

Schottky barrier contacts on defect‐free GaAs (110)

Zuzanna Liliental‐Weber, E. R. Weber, J. Washburn, and J. H. Weaver

Appl. Phys. Lett. 56, 2507 (1990); http://dx.doi.org/10.1063/1.102873 (3 pages) | Cited 4 times

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High resolution transmission electron microscopy and analytical electron microscopy show direct evidence for defect‐free interfaces produced by in situ cluster deposition of Au, Ag, and Ti onto ultrahigh vacuum‐cleaved n‐GaAs. In contrast to interfaces produced by atom‐by‐atom deposition, no specific interface reconstruction or orientation relationship and no change of stoichiometry of the GaAs near the interface was observed. Schottky barrier heights correspond to unusual Fermi level pinning positions in the upper half of the GaAs band gap, in clear contrast to values obtained for atom deposition and for diodes prepared by standard technology on GaAs (100). These results give clear evidence that Fermi level pinning for metal/GaAs interfaces formed without defects does not follow the predictions of current metal‐induced gap‐state models.
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73.30.+y Surface double layers, Schottky barriers, and work functions
68.35.Dv Composition, segregation; defects and impurities
85.30.Hi Surface barrier, boundary, and point contact devices
73.40.Ns Metal-nonmetal contacts

Production of highly oxidized As on GaAs (110) at 20 K

Steven G. Anderson, J. M. Seo, T. Komeda, C. Capasso, and J. H. Weaver

Appl. Phys. Lett. 56, 2510 (1990); http://dx.doi.org/10.1063/1.103259 (3 pages) | Cited 9 times

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High‐resolution synchrotron radiation photoemission results for O2 physisorbed on GaAs (110) show Ga‐O and As‐O formation that is a direct result of photon‐induced reaction at 20 K. Spatially resolved studies show that the thickness and chemical composition of the semiconductor oxides vary in proporition to total beam irradiation. The extent of reaction can be controlled by varying the amount of oxygen present on the surface, and As5+‐like bonding configurations can be formed. These results can only be understood when competition between thermodynamic, kinetic, photon‐ and electron‐mediated processes are considered.
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81.65.-b Surface treatments
61.80.Cb X-ray effects

Observation of silicon wafer emissivity in rapid thermal processing chambers for pyrometric temperature monitoring

J. Nulman, S. Antonio, and W. Blonigan

Appl. Phys. Lett. 56, 2513 (1990); http://dx.doi.org/10.1063/1.102874 (3 pages) | Cited 11 times

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The emissivity of silicon wafers in a rapid thermal processing chamber has been measured as a function of the wafer temperature. Wafers with different surface roughness and layers have been studied. For transparent wafers, both sides of the wafer affect the emissivity. This emissivity is not only affected by surface roughness, but also by the layers deposited on the wafer. It has also been observed that while the emissivity increases rapidly as the temperature increases from its room value to 600 °C, the emissivity decreases with a slope of −8.89×10−5 °C−1 for temperatures larger than 600 °C.
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78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
81.65.-b Surface treatments
78.20.N- Thermo-optic effects
78.20.nb Photothermal effects

High‐conductance customized copper interconnections produced by laser seeding and selective electrodeposition

Arunava Gupta and C. Julian Chen

Appl. Phys. Lett. 56, 2516 (1990); http://dx.doi.org/10.1063/1.102875 (3 pages) | Cited 5 times

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We report a two‐step process for producing high‐conductance customized copper interconnections utilizing a localized electrodeposition process induced by Joule heat at a constriction. An initial metal interconnection is made by localized decomposition of an organometallic film using a focused laser beam. The conductance of such an initial interconnection can be low, but is enough to induce localized copper deposition by passing an ac current through the entire line in a copper‐containing electrolyte. The interconnections produced by this process are solid, continuous, and highly conducting.
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81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
82.30.Lp Decomposition reactions (pyrolysis, dissociation, and fragmentation)
44.25.+f Natural convection
82.45.-h Electrochemistry and electrophoresis

Room‐temperature oxidation of silicon catalyzed by Cu3Si

J. M. E. Harper, A. Charai, L. Stolt, F. M. d’Heurle, and P. M. Fryer

Appl. Phys. Lett. 56, 2519 (1990); http://dx.doi.org/10.1063/1.103260 (3 pages) | Cited 47 times

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We demonstrate remarkably rapid oxidation of (100) silicon at room temperature catalyzed by the presence of Cu3Si. Thermal oxidation of Si is normally carried out at temperatures above 700 °C. Oxidation of many metal silicides occurs more rapidly than that of Si, but under controlled conditions results in a surface layer of SiO2. In contrast, the oxidation process described here produces a thick layer of SiO2 underneath the copper‐rich surface layer. The SiO2 layer grows spontaneously to over 1 μm in thickness in several weeks in air at room temperature. Analysis by Rutherford backscattering, Auger electron spectroscopy, cross‐sectional transmission electron microscopy, and scanning electron microscopy reveals the presence of Cu3Si at the buried SiO2/Si interface, epitaxially related to the underlying Si substrate. Catalytic action by this silicide phase appears responsible for the unusual oxidation process.
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81.65.-b Surface treatments
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
68.35.-p Solid surfaces and solid-solid interfaces: structure and energetics

Deposition of (100) oriented MgO thin films on sapphire by a spray pyrolysis method

W. J. DeSisto and R. L. Henry

Appl. Phys. Lett. 56, 2522 (1990); http://dx.doi.org/10.1063/1.103188 (2 pages) | Cited 11 times

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Thin films of magnesia have been deposited by a novel spray pyrolysis method. An aqueous magnesium acetylacetonate solution was ultrasonically nebulized, transported in flowing oxygen, and thermally decomposed on silicon (100), sapphire, and fused silica at temperatures between 400 and 550 °C. The films were from 0.1 to 0.5 μm thick, optically transparent, and smooth. The MgO films were poorly crystalline as deposited. MgO films on sapphire crystallized with strong (100) orientation after annealing at 700 and 930 °C in flowing oxygen.
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81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
68.55.-a Thin film structure and morphology
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
82.30.Lp Decomposition reactions (pyrolysis, dissociation, and fragmentation)

Temperature dependence of growth of GexSi1−x by ultrahigh vacuum chemical vapor deposition

Marco Racanelli and D. W. Greve

Appl. Phys. Lett. 56, 2524 (1990); http://dx.doi.org/10.1063/1.102876 (3 pages) | Cited 33 times

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We report the deposition of epitaxial films of GexSi1−x on (100) silicon by the ultrahigh vacuum chemical vapor deposition technique. Epitaxial films grown at temperatures ranging from 577 to 665 °C have been characterized with respect to growth rate and germanium content. The results show features which have not been previously reported including an incubation time and a peak in the growth rate as a function of GeH4/H2 flow.
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81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
85.40.Hp Lithography, masks and pattern transfer
85.30.Pq Bipolar transistors

Proposal of novel electron wave coupled devices

N. Tsukada, A. D. Wieck, and K. Ploog

Appl. Phys. Lett. 56, 2527 (1990); http://dx.doi.org/10.1063/1.102877 (3 pages) | Cited 82 times

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We propose a novel structure for electron wave devices that utilizes the mutual coupling effect between electron wave guides. The structure consists of two parallel electron wave guides with a coupling region controlled by a gate voltage. Using simple theoretical calculations, we estimate the switching time and the coupling length required for electron transfer to be 2 ps and 0.28 μm, respectively.
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73.40.Gk Tunneling
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
03.65.Ge Solutions of wave equations: bound states

Diffusion of hydrogen in low‐pressure chemical vapor deposited silicon nitride films

W. M. Arnold Bik, R. N. H. Linssen, F. H. P. M. Habraken, W. F. van der Weg, and A. E. T. Kuiper

Appl. Phys. Lett. 56, 2530 (1990); http://dx.doi.org/10.1063/1.103261 (3 pages) | Cited 21 times

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Hydrogen transport in low‐pressure chemical vapor deposited Si3N4 has been investigated using samples consisting of a double layer of hydrogenated and deuterated nitride films. Concentration depth profiles of hydrogen and deuterium were measured using elastic recoil detection. Diffusion coefficients for D were derived from the deuterium concentration depth profiles before and after annealing at temperatures in the range 700–1000 °C. The diffusion coefficient is characterized by an activation energy of 2.94 eV for the entire temperature range. Its value varies between 10−17 cm2/s at 700 °C and 5×10−14 cm2/s at 1000 °C.
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68.35.Fx Diffusion; interface formation
73.61.Ng Insulators
81.40.Ef Cold working, work hardening; annealing, post-deformation annealing, quenching, tempering recovery, and crystallization

Dynamics of reflection high‐energy electron diffraction intensity oscillations during molecular beam epitaxial growth of GaAs on (111)B GaAs substrates

M. Y. Yen and T. W. Haas

Appl. Phys. Lett. 56, 2533 (1990); http://dx.doi.org/10.1063/1.102878 (3 pages) | Cited 12 times

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We have observed intensity oscillations in reflection high‐energy electron diffraction during molecular beam epitaxial growth of GaAs on (111)B GaAs substrates. These oscillations only exist over a narrow range of growth conditions and their behavior is strongly dependent on the migration kinetics of group III and the molecular dissociative reaction of group V elements.
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81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.35.Fx Diffusion; interface formation
61.05.jh Low-energy electron diffraction (LEED) and reflection high-energy electron diffraction (RHEED)

Electrically inactive grain boundaries in rapid thermal annealed boron‐implanted polycrystalline silicon films

A. Almaggoussi, J. Sicart, J. L. Robert, G. Chaussemy, and A. Laugier

Appl. Phys. Lett. 56, 2536 (1990); http://dx.doi.org/10.1063/1.102879 (3 pages) | Cited 2 times

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The effect of heat treatment rapid thermal annealing (RTA) or conventional thermal annealing on the electrical properties of polycrystalline silicon films implanted with boron in the intermediate concentration range is examined. A standard furnace anneal uniformly redistributes the dopant and results in an electrical activity of grain boundaries (GBs). On the contrary, a rapid thermal anneal does not activate GBs. Impurity gettering does not occur at GBs in RTA and implanted boron does not redistribute uniformly within the grains leading to a strong increase of the Hall mobility in small‐grained silicon films.
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72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
73.61.Cw Elemental semiconductors
73.61.Jc Amorphous semiconductors; glasses
73.61.Le Other inorganic semiconductors
61.72.Mm Grain and twin boundaries
61.72.uf Ge and Si

Amorphous silicon edge detectors for application to neural network image sensors

Wen‐Jyh Sah, Si‐Chen Lee, Hsiung‐Kuang Tsai, and Jyh‐Hong Chen

Appl. Phys. Lett. 56, 2539 (1990); http://dx.doi.org/10.1063/1.102880 (3 pages) | Cited 3 times

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The initial steps in the biological visual signal processing are the extraction of the edge position and its orientation of an object image. These edge detection capabilities can be simulated by semiconductor edge detectors. In this letter, two types of such detectors, i.e., concentric and directional ones for detecting edge and its orientation, respectively, are successfully fabricated using an amorphous silicon hydrogen alloy. The measured performance of these edge detectors is similar to that of the biological ones. A three‐dimensional image array, made by fabricating two‐dimensional amorphous silicon edge detectors on top of the single‐crystal Si very large‐scale integrated circuit is proposed, which can be used as the preprocessor of a smart vision system.
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85.30.De Semiconductor-device characterization, design, and modeling
87.57.-s Medical imaging
87.85.Pq Biomedical imaging

Real‐time observation of molecular beam epitaxy growth on mesa‐etched GaAs substrates by scanning microprobe reflection high‐energy electron diffraction

M. Hata, T. Isu, A. Watanabe, and Y. Katayama

Appl. Phys. Lett. 56, 2542 (1990); http://dx.doi.org/10.1063/1.102881 (3 pages) | Cited 25 times

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Microscopic distribution of growth rates on mesa‐etched GaAs(001) wafers was measured in real time during molecular beam epitaxy growth by scanning microprobe reflection high‐energy electron diffraction. It has been observed that the growth rate on the GaAs(001) surface near the edge of (111)A surfaces becomes larger. The exponential variation of the growth rate as a function of the distance from the edge reflects surface diffusion of Ga atoms. The diffusion length on the (001) surface is estimated to be about 1 μm at 560 °C. The relatively larger diffusion length suggests that the incorporation rate of migrating Ga atoms by steps is much smaller than unity.
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81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
07.79.Cz Scanning tunneling microscopes
61.05.-a Techniques for structure determination
61.05.jh Low-energy electron diffraction (LEED) and reflection high-energy electron diffraction (RHEED)
68.35.Fx Diffusion; interface formation

Temperature dependence of the electronic coherence of GaAs‐GaAlAs superlattices

E. E. Mendez, F. Agulló‐Rueda, and J. M. Hong

Appl. Phys. Lett. 56, 2545 (1990); http://dx.doi.org/10.1063/1.102882 (3 pages) | Cited 29 times

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We have shown that the coherence length of electrons in a 55‐Å‐period GaAs‐GaAlAs superlattice does not depend strongly on temperature in the range 5–292 K, varying from 17 periods at 5 K to a minimum of nine periods at room temperature. The quantum coherence was determined by photocurrent spectroscopy experiments that exploit the formation of Stark ladders in superlattices under electric fields.
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73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
74.25.Bt Thermodynamic properties
74.90.+n Other topics in superconductivity (restricted to new topics in section 74)

Study of inversion layer mobility in metal‐oxide‐semiconductor field‐effect transistors with reoxidized nitrided oxides

G. Q. Lo, W. C. Ting, D. L. Kwong, and S. Lee

Appl. Phys. Lett. 56, 2548 (1990); http://dx.doi.org/10.1063/1.102883 (3 pages) | Cited 2 times

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The carrier effective mobility μeff in the inversion layer for both n‐ and p‐channel metal‐oxide‐semiconductor field‐effect transistors with ultrathin gate dielectrics prepared by rapid thermal reoxidation (RTO) of rapid thermal nitrided (RTN) SiO2 has been studied. It is found that although RTN/RTO degraded the low‐field μeff, it improved significantly the electron μeff under high normal field compared to control SiO2. The effect of RTN/RTO on the hole effective mobility has also been examined and found to be quite different than on the electron effective mobility. A physical mechanism is discussed to account for the observation.
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85.30.Tv Field effect devices
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths

Molecular beam epitaxy versus chemical vapor deposition of silicon on sapphire

Eliezer Dovid Richmond, Mark E. Twigg, Syed Qadri, Joseph G. Pellegrino, and Michael T. Duffey

Appl. Phys. Lett. 56, 2551 (1990); http://dx.doi.org/10.1063/1.102884 (3 pages) | Cited 4 times

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Molecular beam epitaxy (MBE) of Si on sapphire (SOS) has dramatically different and superior properties compared to chemical vapor deposited (CVD) SOS. The strain in the Si epilayer decreases by 21%. A 40% higher electron Hall mobility occurs at room temperature. At LN2 temperatures the electron mobility increases to a level which is more indicative of bulk Si than of CVD SOS. The microtwin differential volume fraction profile is lower by more than an order of magnitude, and decreases below the detectable limit at 300 nm from the interface. The average Si/sapphire interface charge for MBE SOS is −8.0×1010 cm−2, while the interface charge of CVD SOS is 2×1012 cm−2.
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81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
73.61.Cw Elemental semiconductors
73.61.Jc Amorphous semiconductors; glasses
73.61.Le Other inorganic semiconductors
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)

Transmission through a bend in an electron waveguide

Craig S. Lent

Appl. Phys. Lett. 56, 2554 (1990); http://dx.doi.org/10.1063/1.102885 (3 pages) | Cited 43 times

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The transmission properties of a circular, right‐angle bend in a two‐dimensional electron waveguide are calculated. Significant reflections from such a bend would have serious consequences for the development of a quantum electron waveguide technology. The results show nearly perfect transmission around the bend, except for energies very close to the threshold for propagation in the channel. This is true even for rather sharp bends. A significant amount of mode mixing is found, however, for bends with a small radius of curvature.
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73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
71.20.-b Electron density of states and band structure of crystalline solids
73.40.Lq Other semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
03.65.Ge Solutions of wave equations: bound states

Formation of single‐phase PtAs2 films on GaAs by selective oxidation and etching

Eliezer Weiss, Robert C. Keller, Margaret L. Kniffin, and C. R. Helms

Appl. Phys. Lett. 56, 2557 (1990); http://dx.doi.org/10.1063/1.103262 (3 pages) | Cited 1 time

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The oxidation of prereacted Pt films on (100) oriented n‐GaAs substrates was studied in the temperature range between 550 and 750 °C using Auger electron spectroscopy and Xe+ ion profiling. The GaPt/PtAs2/GaAs structure formed during annealing in hydrogen was oxidized using a mixture of water vapor and hydrogen. The GaPt phase can be oxidized completely, whereas the inner PtAs2 and GaAs interfaces are left unoxidized. The oxidation of the platinum‐gallium phase is self‐limited by the diffusion of the Ga through the gallium oxide overlayer. The oxide can be etched off to leave a structure consisting only of platinum‐arsenide on the GaAs substrate.
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81.05.Bx Metals, semimetals, and alloys
81.65.-b Surface treatments
68.35.Fx Diffusion; interface formation
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