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7 Oct 2002

Volume 81, Issue 15, pp. 2677-2902

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Effect of annealing on the In and N distribution in InGaAsN quantum wells

M. Albrecht, V. Grillo, T. Remmele, H. P. Strunk, A. Yu. Egorov, Gh. Dumitras, H. Riechert, A. Kaschner, R. Heitz, and A. Hoffmann

Appl. Phys. Lett. 81, 2719 (2002); http://dx.doi.org/10.1063/1.1509122 (3 pages) | Cited 55 times

Online Publication Date: 30 September 2002

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We analyze the influence of annealing on compositional fluctuations in InGaAsN quantum wells by means of composition-sensitive high-resolution transmission electron microscopy and photoluminescence. In as-grown samples, we find In-concentration fluctuations of ±5% on a length scale of 20 nm in a two-dimensional grown quantum well. No indications for N concentration fluctuations are found within the limits of resolution. Annealing homogenizes the In distribution within the well and causes diffusion of N out of the quantum well. According to our compositional analysis, the blueshift in the photoluminescence can in part be attributed to reduction in N concentration inside the well. The more homogeneous In distribution leads to a reduction in linewidth and Stokes shift. © 2002 American Institute of Physics.
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78.67.De Quantum wells
78.55.Cr III-V semiconductors
68.65.Fg Quantum wells
61.72.Cc Kinetics of defect formation and annealing
78.66.Fd III-V semiconductors
68.37.Lp Transmission electron microscopy (TEM)

The origin of stress reduction by low-temperature AlN interlayers

J. Bläsing, A. Reiher, A. Dadgar, A. Diez, and A. Krost

Appl. Phys. Lett. 81, 2722 (2002); http://dx.doi.org/10.1063/1.1512331 (3 pages) | Cited 50 times

Online Publication Date: 30 September 2002

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Thin low-temperature AlN interlayers can be applied to reduce stress to grow thick crack-free AlGaN layers on GaN buffer layers on sapphire and thick crack-free GaN layers on Si. The mechanism leading to stress reduction is investigated by high resolution x-ray diffractometry measurements on metalorganic chemical vapor phase epitaxy grown samples on Si(111) with different interlayer deposition temperatures. A decrease of tensile stress with decreasing interlayer growth temperature is observed. From reciprocal space maps we conclude that interlayers grown at high temperatures are pseudomorphic, while grown at lower temperatures they are relaxed. Therefore, AlGaN or GaN layers grown on a low temperature AlN interlayer grow under compressive interlayer-induced strain. The stress in the GaN layer depends on the growth temperature that likely controls the amount of AlN interlayer relaxation. © 2002 American Institute of Physics.
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68.55.A- Nucleation and growth
81.15.Kk Vapor phase epitaxy; growth from vapor phase
FREE

Giant microcavity enhancement of second-harmonic generation in all-silicon photonic crystals

T. V. Dolgova, A. I. Maidykovski, M. G. Martemyanov, A. A. Fedyanin, O. A. Aktsipetrov, G. Marowsky, V. A. Yakovlev, and G. Mattei

Appl. Phys. Lett. 81, 2725 (2002); http://dx.doi.org/10.1063/1.1510968 (3 pages) | Cited 35 times

Online Publication Date: 30 September 2002

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Second-harmonic generation (SHG) spectra of single and coupled porous silicon-based photonic crystal microcavities are studied in both frequency and wave vector domains. For the fundamental field resonant to the microcavity mode the second-harmonic intensity is enhanced by 102 times in comparison with that outside the photonic band gap. SHG spectroscopy in identical microcavities coupled through the intermediate Bragg reflector reveals two SHG peaks if the fundamental field is in resonance with the splitted mode of coupled microcavities. The spatial confinement of the resonant fundamental radiation is directly probed at the microcavity cleavage by scanning near-field optical microscopy. © 2002 American Institute of Physics.
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42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
42.70.Qs Photonic bandgap materials

Z-contrast imaging of dislocation cores at the GaAs/Si interface

S. Lopatin, S. J. Pennycook, J. Narayan, and G. Duscher

Appl. Phys. Lett. 81, 2728 (2002); http://dx.doi.org/10.1063/1.1511808 (3 pages) | Cited 17 times

Online Publication Date: 30 September 2002

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The interface between silicon and epitaxial GaAs thin film grown by metalorganic chemical vapor deposition was studied using atomic-resolution Z-contrast imaging. Z-contrast imaging provides chemical composition information and allows direct interpretation of micrographs without simulation. Three different types of dislocations were identified. As expected, a dangling bond was found in the atomic structure of the 60° dislocation. One of the observed 90° dislocations had the reconstructed atomic core structure (with no dangling bonds). The core structure of the other 90° dislocation exhibited a dangling bond. © 2002 American Institute of Physics.
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61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)
68.37.Lp Transmission electron microscopy (TEM)
68.35.Ct Interface structure and roughness
81.05.Ea III-V semiconductors
81.05.Cy Elemental semiconductors
61.72.Lk Linear defects: dislocations, disclinations
07.78.+s Electron, positron, and ion microscopes; electron diffractometers

Optical diffraction gratings produced by laser interference structuring of amorphous germanium–nitrogen alloys

M. Mulato, A. R. Zanatta, D. Toet, and I. E. Chambouleyron

Appl. Phys. Lett. 81, 2731 (2002); http://dx.doi.org/10.1063/1.1512307 (3 pages) | Cited 1 time

Online Publication Date: 30 September 2002

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We use the interference of two pulsed laser beams (wavelength = 355 nm) to produce an optical diffraction grating in amorphous germanium–nitrogen alloy (a-GeN). At the constructive maxima of the interference pattern, the absorption of light leads to crystallization. The crystallized region results of pure microcrystalline germanium (μc-Ge). An indication that Ge–N bonds have broken and nitrogen outdiffused of the film is obtained from infrared spectroscopy and confirmed by Raman spectra. A pattern of alternating a-GeN and μc-Ge lines with a period of about 4 μm acts as an optical diffraction grating due to the difference in optical properties between the two materials, and the three dimensional surface profile, caused by N2 effusion, that is formed on the sample. © 2002 American Institute of Physics.
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42.79.Dj Gratings
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
42.62.-b Laser applications
78.66.Jg Amorphous semiconductors; glasses
61.82.Fk Semiconductors
61.43.Dq Amorphous semiconductors, metals, and alloys
78.35.+c Brillouin and Rayleigh scattering; other light scattering

Effects of carbon codoping on lattice locations of erbium in silicon

M. B. Huang and X. T. Ren

Appl. Phys. Lett. 81, 2734 (2002); http://dx.doi.org/10.1063/1.1510960 (3 pages) | Cited 5 times

Online Publication Date: 30 September 2002

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The effects of carbon codoping on the lattice location of Er atoms in silicon have been investigated using ion beam channeling. A float-zone (FZ) Si (100) wafer was first amorphized to a depth of ∼ 0.3 μm by Si ion implantation at 77 K. The amorphous Si layer was then implanted with carbon ions, and recrystallized via solid phase epitaxial growth. Finally, Er ions were implanted into C-doped and C-free Si samples at 300 °C. Angular scans along three major crystalline directions, that is, 〈100〉, 〈110〉, and 〈111〉, were performed for Er-implanted Si with and without C codoping. In FZ-Si, in which the carbon concentration is very low (<1016 cm−3), a large fraction ( ∼ 50%) of implanted Er atoms are found to occupy the near-tetrahedral (T) interstitial site, while few Er atoms are on the hexagonal (H) interstitial site. It is evident that the incorporation of C into Si tends to decrease the fraction of T-site Er atoms and relocate them to the H site. We have also determined the effective number ( ∼ 1.5) of carbon atoms required for depopulating an Er atom from the T site to H site. Implications on the configuration of Er luminescence centers are discussed. © 2002 American Institute of Physics.
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61.72.S- Impurities in crystals
61.72.uf Ge and Si
61.85.+p Channeling phenomena (blocking, energy loss, etc.)
61.82.Fk Semiconductors
61.80.Jh Ion radiation effects
78.55.Ap Elemental semiconductors

Interferometric correlation spectroscopy in single quantum dots

C. Kammerer, G. Cassabois, C. Voisin, M. Perrin, C. Delalande, Ph. Roussignol, and J. M. Gérard

Appl. Phys. Lett. 81, 2737 (2002); http://dx.doi.org/10.1063/1.1510158 (3 pages) | Cited 42 times

Online Publication Date: 30 September 2002

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We report high-resolution spectroscopy by interferometric correlation measurements on the photoluminescence signal of a single quantum dot. We demonstrate that the insertion of a Michelson interferometer in the detection path gives a compact and flexible setup for linewidth measurements. We have used this technique to study self-assembled InAs/GaAs quantum dots. We observe linewidth variations from one quantum dot to another, and we bring evidence of environment effects on the broadening processes. © 2002 American Institute of Physics.
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78.67.Hc Quantum dots
78.55.Cr III-V semiconductors

Thickness determination of very thin SiO2 films on Si by electron-induced x-ray emission spectroscopy

C. Hombourger, P. Jonnard, E. O. Filatova, and V. Lukyanov

Appl. Phys. Lett. 81, 2740 (2002); http://dx.doi.org/10.1063/1.1511281 (3 pages) | Cited 2 times

Online Publication Date: 30 September 2002

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Electron-induced x-ray emission spectroscopy (EXES) associate with a semi-empirical electron scattering model is used to determine thicknesses between 2 and 21 nm of SiO2 films on Si. The small charging effect occurring upon electron irradiation is taken into account by introducing a retarding potential in the model. The results are in very close agreement with those obtained by spectroscopic ellipsometry and x-ray reflectometry. It is demonstrated that the EXES with its model is a well-suited method for the quantitative analysis of thin insulating films with an uncertainty lower than 5%. © 2002 American Institute of Physics.
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06.30.Bp Spatial dimensions (e.g., position, lengths, volume, angles, and displacements)
78.70.En X-ray emission spectra and fluorescence
61.80.Fe Electron and positron radiation effects
61.82.Ms Insulators

On the origin of the blueshift from type-II quantum dots emission using microphotoluminescence

M. K. K. Nakaema, F. Iikawa, M. J. S. P. Brasil, E. Ribeiro, G. Medeiros-Ribeiro, W. Carvalho, M. Z. Maialle, and M. H. Degani

Appl. Phys. Lett. 81, 2743 (2002); http://dx.doi.org/10.1063/1.1511812 (3 pages) | Cited 14 times

Online Publication Date: 30 September 2002

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We have studied type-II InP/GaAs self-assembled quantum dots by microphotoluminescence spectroscopy. Sharp spectral features were observed on top of a broad emission band. They are associated to statistical fluctuations from the ensemble of dots. Photoluminescence measurements as a function of the excitation intensity revealed markedly distinct behaviors: the broadband contour shows a large blueshift while the energy positions of the sharp features remain basically constant. We show that the large blueshift of the broad emission band in type-II quantum dots is not due to the barrier interface potential variation, but to the state filling of higher-energy states. © 2002 American Institute of Physics.
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78.67.Hc Quantum dots
81.07.Ta Quantum dots
78.55.Cr III-V semiconductors
81.05.Ea III-V semiconductors
73.21.La Quantum dots

Surface roughening of tensilely strained Si1−x−yGexCy films grown by ultrahigh vacuum chemical vapor deposition

Cyril Calmes, D. Bouchier, D. Débarre, and C. Clerc

Appl. Phys. Lett. 81, 2746 (2002); http://dx.doi.org/10.1063/1.1505114 (3 pages) | Cited 3 times

Online Publication Date: 30 September 2002

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Using in situ reflection high-energy electron diffraction, we have studied the surface roughening of SiGeC that occurs in ultrahigh vacuum chemical vapor deposition under certain growth conditions. For a given SiH3CH3 fraction in the gas phase, high growth rates and low temperatures are found to be favorable to obtain smooth surfaces. Roughening is accompanied by a dramatic decrease of the substitutional C content. According to these observations, we propose a model of surface roughening based on the formation of carboneous complexes on the film surface, limited by the growth rate and the diffusion length of C adatoms. From that, a critical ratio between the growth rate and the C diffusion coefficient was assumed. Its temperature dependence was determined. The activation energy of C adatoms diffusion was found to be close to the well known value for hydrogen desorption. © 2002 American Institute of Physics.
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68.35.Fx Diffusion; interface formation
68.35.B- Structure of clean surfaces (and surface reconstruction)
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.55.-a Thin film structure and morphology
68.43.Jk Diffusion of adsorbates, kinetics of coarsening and aggregation

Sr3Al10SiO20:Eu2+ as a blue luminescent material for plasma displays

Shunichi Kubota and Masahiko Shimada

Appl. Phys. Lett. 81, 2749 (2002); http://dx.doi.org/10.1063/1.1512306 (3 pages) | Cited 23 times

Online Publication Date: 30 September 2002

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A new luminescent material, Sr3Al10SiO20:Eu2+, has been synthesized. The material exhibits an emission peak at 466 nm for the (Sr0.993Eu0.007)3Al10SiO20 and a CIE chromaticity of (x = 0.145, y = 0.124), with relative intensity of 60% of commercial phosphor BaMgAl10O17:Eu2+ under vaccum ultraviolet excitation. © 2002 American Institute of Physics.
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78.55.Hx Other solid inorganic materials
85.60.Pg Display systems
52.75.-d Plasma devices

Thermodynamic equilibrium and metal-organic interface dipole

Li Yan, N. J. Watkins, S. Zorba, Yongli Gao, and C. W. Tang

Appl. Phys. Lett. 81, 2752 (2002); http://dx.doi.org/10.1063/1.1512826 (3 pages) | Cited 39 times

Online Publication Date: 30 September 2002

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We determined the interface dipoles at a number of metal-organic interfaces using ultraviolet and x-ray photoelectron spectroscopy. A linear dependence of the dipole on the metal work function is observed. This is consistent with the theory based on the charge transfer and thermodynamic equilibrium across the interface. The agreement suggests that charge transfer is one major factor in the formation of interface dipole. In addition, we find that the pushing back of the electron cloud tail that extends out of the metal surface and the permanent dipole moment of the organic molecule affect the interface dipole. © 2002 American Institute of Physics.
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73.40.Ns Metal-nonmetal contacts
73.30.+y Surface double layers, Schottky barriers, and work functions
79.60.Jv Interfaces; heterostructures; nanostructures
73.20.-r Electron states at surfaces and interfaces
73.61.Ph Polymers; organic compounds

Near-band-edge photoluminescence of wurtzite-type AlN

E. Kuokstis, J. Zhang, Q. Fareed, J. W. Yang, G. Simin, M. Asif Khan, R. Gaska, M. Shur, C. Rojo, and L. Schowalter

Appl. Phys. Lett. 81, 2755 (2002); http://dx.doi.org/10.1063/1.1510586 (3 pages) | Cited 38 times

Online Publication Date: 30 September 2002

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Temperature-dependent photoluminescence (PL) measurements were performed for A-plane and C-plane bulk AlN single crystals and epitaxial layers on sapphire. A strong near-band-edge (NBE) emission and deep-level luminescence were observed. At low excitations, the emission spectra are dominated by free and bound excitonic transitions and their LO-phonon replicas. At high excitations, the broadening and redshift of the NBE band is attributed to dense electron–hole plasma formation. The PL spectra differences of bulk single crystals and epilayers is explained by the electron–hole plasma expansion peculiarities. © 2002 American Institute of Physics.
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78.55.Cr III-V semiconductors
78.66.Fd III-V semiconductors
71.20.Nr Semiconductor compounds
71.35.Ee Electron-hole drops and electron-hole plasma
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping

Minimizing threading dislocations by redirection during cantilever epitaxial growth of GaN

D. M. Follstaedt, P. P. Provencio, N. A. Missert, C. C. Mitchell, D. D. Koleske, A. A. Allerman, and C. I. H. Ashby

Appl. Phys. Lett. 81, 2758 (2002); http://dx.doi.org/10.1063/1.1511286 (3 pages) | Cited 14 times

Online Publication Date: 30 September 2002

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A 40-fold reduction in density of vertical threading dislocations (VTDs) at the surface of GaN is obtained with cantilever epitaxy by using narrow (<1 μm) mesas etched into a sapphire substrate and conditions producing angled {11-22} facets to initiate growth by metalorganic chemical vapor deposition. These two techniques redirect VTDs over the mesas to the horizontal and away from device areas above. Further reductions appear possible if the facets uniformly cover all mesas prior to cantilever growth. © 2002 American Institute of Physics.
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68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.05.Ea III-V semiconductors
61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)

Violet-blue photoluminescent properties of mesoporous zirconia modified with phosphoric acid

Hang-Rong Chen, Jian-Lin Shi, Yong Yang, Yong-Sheng Li, Dong-Sheng Yan, and Chao-Shu Shi

Appl. Phys. Lett. 81, 2761 (2002); http://dx.doi.org/10.1063/1.1512825 (3 pages) | Cited 8 times

Online Publication Date: 30 September 2002

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Two strong violet-blue luminescence emissions at 390 and 440 nm under excitation at room temperature have been observed in the ordered mesoporous zirconium oxide post-treated with phosphoric acid. The oxide was characterized by powder x-ray diffraction, nitrogen adsorption, diffuse reflectance UV-vis spectroscopy, x-ray fluorescence analysis, and time-resolved photoluminescence decay spectra. It is concluded that these photoluminescence responses are related to the presence of P–O–Zr lumophores in tetrapodal framework due to the post-treatment with phosphoric acid, and are also related to the defects of oxygen vacancies in the mesoporous zirconia itself. The significant optical properties of this material may be very interesting for further application. © 2002 American Institute of Physics.
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78.55.Mb Porous materials
81.05.Rm Porous materials; granular materials
78.47.-p Spectroscopy of solid state dynamics
78.40.Ha Other nonmetallic inorganics
68.43.Mn Adsorption kinetics
61.72.J- Point defects and defect clusters

Structural, dielectric, and magnetic properties of epitaxially grown BaFeO3 thin films on (100) SrTiO3 single-crystal substrates

T. Matsui, H. Tanaka, N. Fujimura, T. Ito, H. Mabuchi, and K. Morii

Appl. Phys. Lett. 81, 2764 (2002); http://dx.doi.org/10.1063/1.1513213 (3 pages) | Cited 27 times

Online Publication Date: 30 September 2002

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We have prepared single-crystalline films of BaFeO3, which may contain high valent Fe4+ ions, on (100) SrTiO3 substrates by pulsed laser-beam deposition. The reflection high-energy electron diffraction patterns for the films apparently show a C4 symmetry operation, suggesting that the sample had a pseudocubic perovskite structure rather than hexagonal unit cell. The films were found to be highly insulating, and showed a high value of dielectric constant of ε = 59. At 300 K, the magnetization loop of the film apparently shows hysteresis, as well as small remanent magnetization. These characteristics are totally different from those of bulk BaFeO3. © 2002 American Institute of Physics.
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68.55.-a Thin film structure and morphology
75.70.Ak Magnetic properties of monolayers and thin films
77.55.-g Dielectric thin films
81.15.Fg Pulsed laser ablation deposition
68.55.A- Nucleation and growth
77.80.-e Ferroelectricity and antiferroelectricity
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
77.22.Ch Permittivity (dielectric function)
75.50.Dd Nonmetallic ferromagnetic materials
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects

Impurity incorporation in InGaN grown by rf plasma-assisted molecular beam epitaxy

C. Poblenz, T. Mates, M. Craven, S. P. DenBaars, and J. S. Speck

Appl. Phys. Lett. 81, 2767 (2002); http://dx.doi.org/10.1063/1.1512817 (3 pages) | Cited 7 times

Online Publication Date: 30 September 2002

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Impurity incorporation into InGaN films grown by rf-plasma assisted molecular beam epitaxy was investigated using secondary ion mass spectroscopy. A factor of 3 increase in both oxygen and boron incorporation into InGaN films relative to GaN films at 600 °C was demonstrated, and a factor of 10 increase in oxygen relative to the detectable base line in GaN grown under optimal conditions. Oxygen incorporation is related specifically to the different structures of the gallium and indium wetting layers on the growth surface. It is also shown using secondary ion mass spectroscopy that the formation of the gallium wetting layer during GaN growth is disrupted by the presence of excess indium; increased oxygen incorporation was observed during growth with an incomplete gallium wetting layer and indium on the growth surface. This study demonstrates the profound impact of surface atomic structure on impurity incorporation and reveals the protective nature of the gallium wetting layer as compared to the indium wetting layer during growth by rf-plasma assisted molecular beam epitaxy. © 2002 American Institute of Physics.
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81.05.Ea III-V semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
61.72.S- Impurities in crystals
52.77.Dq Plasma-based ion implantation and deposition
82.80.Ms Mass spectrometry (including SIMS, multiphoton ionization and resonance ionization mass spectrometry, MALDI)
68.35.B- Structure of clean surfaces (and surface reconstruction)

Si(100) surface morphology evolution during normal-incidence sputtering with 100–500 eV Ar+ ions

F. Ludwig, C. R. Eddy, O. Malis, and R. L. Headrick

Appl. Phys. Lett. 81, 2770 (2002); http://dx.doi.org/10.1063/1.1513655 (3 pages) | Cited 26 times

Online Publication Date: 30 September 2002

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Grazing incidence small-angle x-ray scattering and atomic force microscopy have been used to systematically investigate the evolution of Si(100) surface morphology during normal-incidence Ar+ sputtering as a function of ion energy in the range of 100–500 eV. For ion energy ranges of 100–300 eV, two structures with distinct individual length scales and behaviors form on the surface. There is a smaller scale (lateral size of 20–50 nm) morphology that grows in scattering intensity and coarsens with time. There is also a larger scale (lateral size of approximately 100 nm) morphology that grows in scattering intensity but does not coarsen significantly in the time scales studied. At higher energies (400–500 eV), sputtering causes the Si(100) surface to become smoother on length scales smaller than 200 nm. © 2002 American Institute of Physics.
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68.35.B- Structure of clean surfaces (and surface reconstruction)
68.49.Sf Ion scattering from surfaces (charge transfer, sputtering, SIMS)
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces
68.37.Ps Atomic force microscopy (AFM)
61.05.cf X-ray scattering (including small-angle scattering)

Effect of Si doping on the relaxation mechanism of InGaAs on GaAs

P. J. Parbrook, B. K. Tanner, B. Lunn, J. H. C. Hogg, A. M. Keir, and A. D. Johnson

Appl. Phys. Lett. 81, 2773 (2002); http://dx.doi.org/10.1063/1.1513181 (3 pages) | Cited 3 times

Online Publication Date: 30 September 2002

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We report measurements on the initial stages of relaxation of Si-doped In0.04Ga0.96As epitaxial layers on (001) GaAs using in situ high-resolution double-crystal x-ray topography during molecular beam epitaxial growth. For Si concentrations up to 5×1018 cm−3, the critical thickness for formation of the first B(g) misfit dislocations is modeled accurately by the Matthews–Blakeslee model, extended to include a lattice friction force varying linearly with the dopant concentration. Below a Si concentration of 2×1018 cm−3, the model can be used to predict the critical thickness for generation of the orthogonal A(g) dislocation set, with the x-ray topographs showing that the B(g) misfit multiplication occurs at damaged edges of the wafer. However, above 2×1018 cm−3 Si concentration, the critical thickness for A(g) nucleation becomes almost independent of concentration and the x-ray topographs show that cross slip becomes important in the multiplication process. For most of the Si concentrations examined, the critical thickness for nucleation of the slow A(g) misfit dislocations corresponded to that of multiplication of the fast B(g) set. © 2002 American Institute of Physics.
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61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)
61.72.Lk Linear defects: dislocations, disclinations
68.55.-a Thin film structure and morphology
61.72.Bb Theories and models of crystal defects

Structural study of a commensurate phase at Co/Si(111) interface using in situ surface x-ray scattering

T. S. Kang, J. H. Je, H. J. Kim, D. Y. Noh, N. D. Kim, and J. W. Chung

Appl. Phys. Lett. 81, 2776 (2002); http://dx.doi.org/10.1063/1.1513658 (3 pages) | Cited 1 time

Online Publication Date: 30 September 2002

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Interfacial structure and reaction stoichiometry of the Co-adsorbed Si(111) surface at room temperature has been studied by in situ synchrotron surface x-ray scattering. The intensity oscillation at the anti-Bragg position of the (1,0) off-specular crystal truncation rod indicates a layerwise consumption of silicon substrate during the deposition of the first 15 Co monolayers. Our data suggest that an interfacial silicide layer formed in the initial stage of growth have the atomic stoichiometry of Co2Si. The silicide layer is a commensurate phase of pseudohexagonal Co2Si, which shows a long-range order with large strain imposed by the Si substrate. © 2002 American Institute of Physics.
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68.35.Ct Interface structure and roughness
68.35.Dv Composition, segregation; defects and impurities
78.70.Ck X-ray scattering
61.66.Bi Elemental solids
61.66.Dk Alloys
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