Pb Induced Layer-by-Layer Growth and the Dependence on an Amount of Surfactant in the Growth of Ni on Ni(100) Surface

1996 ◽  
Vol 441 ◽  
Author(s):  
M. Iwanami ◽  
M. Kamiko ◽  
T. Matsumoto ◽  
R. Yamamoto
Keyword(s):  
Film Growth ◽  
Three Dimensional ◽  
High Energy ◽  
Layer Growth ◽  
Embedded Atom Method ◽  
Layer By Layer ◽  
Homoepitaxial Growth ◽  
Embedded Atom ◽  
Series Of Experiments ◽  
Modified Embedded Atom Method

AbstractSurfactant epitaxy has been expected to be a powerful method to improve thin film growth from three dimensional island mode to layer-by-layer growth one. Supposing that Pb is the surfactant and Ni is the substrate and deposition metal, we have investigated how the surfactant atoms segregate on surface by computer simulations using the modified embedded atom method. To verify the effect of Pb on the homoepitaxial growth of Ni, we have performed a series of experiments on the growth of Ni on Ni(100) surface with and without Pb using reflection high energy electron diffraction (RHEED). It was clearly found that Pb induced layer-by-layer growth of Ni metal film. The result of the dependence of the growth behavior on the thickness of Pb layer suggests that there is the most suitable thickness of a surfactant layer which is not always the monolayer.

Structural Defects and Their Relationship to Nucleation of Gan Thin Films

1996 ◽  
Vol 423 ◽  
Author(s):  
Weida Gian ◽  
Marek Skowronski ◽  
Greg S. Rohrer
Keyword(s):  
Film Growth ◽  
Three Dimensional ◽  
Scanning Force Microscopy ◽  
Columnar Structure ◽  
Layer Growth ◽  
Buffer Layers ◽  
Structural Defects ◽  
Layer By Layer ◽  
Extended Defects ◽  
Edge Dislocations

AbstractMicrostructure and extended defects in α-GaN films grown by organometallic vapor phase epitaxy on sapphire substrates using low temperature AIN (or GaN) buffer layers have been studied using transmission electron microscopy. The types and distribution of extended defects were correlated with the film growth mode and the layer nucleation mechanism which was characterized by scanning force microscopy. The nature of the extended defects was directly related to the initial three-dimensional growth. It was found that inhomogeneous nucleation leads to a grain-like structure in the buffer; the GaN films then have a columnar structure with a high density of straight edge dislocations at grain boundaries which are less likely to be suppressed by common annihilation mechanisms. Layer-by-layer growth proceeds in many individual islands which is evidenced by the observation of hexagonal growth hillocks. Each growth hillock has an open-core screw dislocation at its center which emits monolayer-height spiral steps.

Bismuth-Induced Layer-by-Layer Growth in the Homoepitaxial Growth of Fe(100)

2002 ◽  
Vol 749 ◽  
Author(s):  
Masao Kamiko ◽  
Hiroaki Chihaya ◽  
Hiroyuki Mizuno ◽  
Junhua Xu ◽  
Isao Kojima ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Surface Segregation ◽  
High Energy ◽  
Layer Growth ◽  
Growth Behavior ◽  
Layer By Layer ◽  
High Energy Electron ◽  
Optimum Amount ◽  
Homoepitaxial Growth ◽  
Strong Surface

ABSTRACTWe have investigated the effect of Bi on the homoepitaxial growth of Fe(100) by means of reflection high-energy electron diffraction (RHEED). It was clearly found that Bi induces layer-by-layer growth of Fe on Fe(100)-c(2×2)O reconstruction surface. The result of the dependence of the growth behavior as a function of Bi layer thickness suggests that there is optimum amount of Bi surfactant layer that induces the smoother layer-by-layer growth. A strong surface segregation of Bi was found at the top of surface and acts as a surfactant by promoting the interlayer transport.

Oxygen Pressure Dependence of Morphology of Morphology of La2-xSrxCuO4 Ultra-Thin Films

1997 ◽  
Vol 11 (21n22) ◽  
pp. 981-987
Author(s):  
H. Q. Yin ◽  
T. Arakawa ◽  
Y. Kaneda ◽  
T. Yoshikawa ◽  
N. Haneji ◽  
...  
Keyword(s):  
Thin Films ◽  
Pressure Dependence ◽  
Film Growth ◽  
Ambient Pressure ◽  
High Energy ◽  
Layer Growth ◽  
Growth Mode ◽  
Layer By Layer ◽  
Island Growth ◽  
Experimental Conditions

La 2-x Sr x CuO 4 ultra-thin films with thickness 200 Å were fabricated by pulsed laser deposition method in oxygen ( O 2) atmosphere. The morphology of deposited films was investigated by reflection high energy electron diffraction (RHEED), atomic force microscopy (AFM) and scanning electronic microscopy (SEM). The strong oxygen ambient pressure dependence of film morphology was observed. In high oxygen ambient pressure, the film growth is dominated by island growth mode. The results imply that the experimental conditions of oxygen ambient pressure and substrate temperature are critical for the layer-by-layer growth mode.

Atomistic Modeling of Ultrathin Fe Films on Cu (111)

2000 ◽  
Vol 616 ◽  
Author(s):  
A. Rakotomahevitra ◽  
L. T. Wille ◽  
M. S. Rakotomalala
Keyword(s):  
Md Simulations ◽  
Layer Growth ◽  
Iron Film ◽  
Embedded Atom Method ◽  
Layer By Layer ◽  
Atomistic Modeling ◽  
Iron Films ◽  
Embedded Atom ◽  
Force Range ◽  
Atom Energy

AbstractWe have used the embedded-atom method (EAM) to perform molecular-dynamics (MD) simulations of iron films grown on Cu (111). The iron atoms were randomly deposited, one at a time, above the surface just within the force range of the nearest surface atom. The growth mode is discussed by following the iron film coverage for an incident-atom energy ranged from 0.5eV to 15eV. A transition from island to layer by layer growth is observed as a function of incident energy. The effect of deposition rate is also studied.

scholarly journals Molecular Dynamics Simulation of Cascade Damage in Gold

1996 ◽  
Vol 439 ◽  
Author(s):  
E. Alonso ◽  
M. J. Caturla ◽  
M. Tang ◽  
H. Huang ◽  
T. Diaz de ia Rubia
Keyword(s):  
Molecular Dynamics ◽  
High Pressures ◽  
High Energy ◽  
Dynamics Simulation ◽  
Embedded Atom Method ◽  
Embedded Atom ◽  
Energy Cascades ◽  
Modified Embedded Atom Method ◽  
Embedded Atom Method Potential ◽  
Cascade Damage

AbstractHigh-energy cascades have been simulated in gold using molecular dynamics with a modified embedded atom method potential. The results show that both vacancy and interstitial clusters form with high probability as a result of intracascade processes. The formation of clusters has been interpreted in terms of the high pressures generated in the core of the cascade during the early stages. We provide evidence that correlation between interstitial and vacancy clustering exists.

GROWTH, MORPHOLOGICAL AND STRUCTURAL PROPERTIES OF Ag THIN FILMS ON A Ru (0001) SURFACE GROWN BY MBE

2004 ◽  
Vol 11 (06) ◽  
pp. 563-568
Author(s):  
A. AZIZI ◽  
J. ARABSKI ◽  
A. DINIA
Keyword(s):  
Thin Films ◽  
Lattice Mismatch ◽  
Three Dimensional ◽  
Xrd Analysis ◽  
High Energy ◽  
Growth Direction ◽  
Layer Growth ◽  
Layer By Layer ◽  
Force Microscopy ◽  
Xrd Techniques

Ag thin films deposited on Ru (0001) surface by molecular beam epitaxy, at temperatures of 20°C and 450°C, have been investigated using reflection high-energy electron diffraction (RHEED), atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques. For both growth temperatures, the in situ RHEED patterns of the Ag films exhibited an in-plane six-fold symmetry, indicating that the Ag deposit is in epitaxy with the Ru buffer surface. At RT, the RHEED technique indicated a three-dimensional growth (3D), while a layer-by-layer growth (2D) takes place at HT. The AFM images showed a granular structure of the surface of the deposited Ag layers with a large variation of the roughness with the growth temperature. XRD analysis gave indication of a strongly textured thin film along the growth direction. The lattice mismatch between the Ag and Ru is at the origin of a stress at the interface and defects structure in the film.

Initial Stage of Heteroepitaxial Growth of SiC on Si by Gas Source MBE Using Hydrocarbon Radicals

1993 ◽  
Vol 318 ◽  
Author(s):  
Takashi Fuyuki ◽  
Yoichiro Tarui ◽  
Tomoaki Hatayama ◽  
Hiroyuki Matsunami
Keyword(s):  
Molecular Beam ◽  
High Energy ◽  
Layer Growth ◽  
Layer By Layer ◽  
Heteroepitaxial Growth ◽  
Homoepitaxial Growth ◽  
Gas Source ◽  
Initial Stage ◽  
Hydrocarbon Radicals ◽  
Gas Source Mbe

ABSTRACTHeteroepitaxial growth of 3C-SiC on Si in gas source molecular beam epitaxy ( GSMBE ) was carried out by a combination of carbonization of a Si surface and subsequent crystal growth on it using hydrocarbon radicals and Si2H6. The carbonization process and the initial stage of the subsequent growth during the intermittent supply of Si2H6 have been studied by a reflection high-energy electron diffraction (RHEED) observation. A Si surface was chemically converted to 3C-SiC at 750°C, and homoepitaxial growth on the carbonized layer could be obtained at 1000°C. Si atoms generated by thermal decomposition on a surface would react with hydrocarbon radicals, forming SiC through a layer by layer growth mode.

Direct Observations of the Strain-Limited Island Growth of Sn-Doped GaAs(100)

1998 ◽  
Vol 05 (03n04) ◽  
pp. 783-795 ◽  
Author(s):  
A. M. Dabiran ◽  
S. M. Seutter ◽  
P. I. Cohen
Keyword(s):  
Native Species ◽  
Surface Segregation ◽  
High Surface ◽  
Three Dimensional ◽  
High Energy ◽  
Layer Growth ◽  
Scanning Tunneling ◽  
Layer By Layer ◽  
Island Growth ◽  
Tunneling Microscopy

We have used scanning tunneling microscopy (STM) in ultrahigh vacuum and atomic force microscopy (AFM) in air to investigate the microscopic mechanisms of Sn surface segregation during the molecular beam epitaxial growth of GaAs and AlAs(100). Submonolayer amounts of Sn segregate to the surface during growth and strongly modify the growth kinetics. This is indicated by both extra-ordinary reflection high energy electron diffraction (RHEED) measurements, and the STM and AFM images of rapidly quenched growth fronts. At the high surface coverages of 0.1–0.6 monolayers of Sn, studied in this work, neither step bunching nor three-dimensional (3D) growth of GaAs(100), was observed. Instead, STM and RHEED measurements indicated a significantly enhanced layer-by-layer growth of GaAs with increasing surface coverage of Sn. STM snapshots of the initial stages of GaAs growth revealed 2D islands which contained a higher-than-equilibrium bulk concentration of Sn, in Ga-substitutional sites, of up to 50%. Other directly observed Sn effects which are presented in this work include the removal of GaAs(100) island growth anisotropy and the formation of 2D islands with a relatively narrow distribution of size and separation. The completion of the top layers is shown to proceed by the coalescence of these islands before any significant nucleation of the next layer islands. This effect is used to explain the Sn enhancement of the layer-by-layer growth which was indicated in our RHEED and scanning probe observations. A model is presented for Sn segregation which explains these results based on an island-size-dependent, strain-driven, oscillatory Sn occupation of Ga-substitutional sites and surface interstitial sites on top GaAs(100) layers during growth. This model, which introduces a strain-limiting mechanism for the size and shape of the 2D islands, can also explain the observed enhancement of postgrowth surface recovery, as well as a delayed onset in increasing adatom surface diffusion length with increasing Sn coverage. The main conclusion is that, if impurity incorporation results in significant strain, then in addition to step climbing by surface impurities, the exchange of incorporated impurities with native species in top layers can be an important path for impurity segregation during expitaxial growth.

Growth of High-Quality Pb(ZrxTi1-x)O3 Films by Peroxide MBE and Their Optical and Structural Characteristics

2006 ◽  
Vol 966 ◽  
Author(s):  
Natalia Izyumskaya ◽  
Vitaliy Avrutin ◽  
Xing Gu ◽  
Umit Ozgur ◽  
Bo Xiao ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Three Dimensional ◽  
High Energy ◽  
Layer Growth ◽  
In Situ Monitoring ◽  
Layer By Layer ◽  
Pzt Film ◽  
Pzt Films ◽  
Dimensional Growth

ABSTRACTThe growth of Pb(ZrxTi1-x)O3 (PZT) films by molecular beam epitaxy was demonstrated. Single-crystal, single-phase PZT films were grown on (001) SrTiO3 substrates at a growth temperature of 600°C. In situ monitoring of the growth process by reflection high-energy electron diffraction revealed two dimensional growth for the PZT constituent ternaries, namely, PbTiO3 and PbZrO3, and three-dimensional growth for PZT films of intermediate compositions. Layer-by-layer growth of PZT films, however, was achieved by using a PbTiO3 buffer layer between the SrTiO3 substrate and PZT films. Optical properties of the films of the end ternaries were investigated by spectroscopic ellipsometry. Refractive index at 633 nm was found to be 2.66 for PbTiO3 and 2.40 for PbZrO3. Band gap energies of PbTiO3 and PbZrO3 were determined as 3.81 and 3.86 eV, in good agreement with theoretically calculated values. The P-E hysteresis loop of a 70-nm-thick PZT film was well saturated and had a square shape. The remanent polarization and the coercive field were 83 μC/cm2 and 77 kV/cm, respectively, which are respectable.

Germanium Nanostructures on Silicon Observed by Scanning Probe Microscopy

MRS Bulletin ◽  
2004 ◽  
Vol 29 (7) ◽  
pp. 484-487 ◽  
Author(s):  
Masahiko Tomitori ◽  
Toyoko Arai
Keyword(s):  
Scanning Probe Microscopy ◽  
Film Growth ◽  
Three Dimensional ◽  
Layer Growth ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Layer By Layer ◽  
Tunneling Microscopy ◽  
Probe Microscopy ◽  
History Of

AbstractScanning tunneling microscopy and noncontact atomic force microscopy have been used to observe germanium growth on Si(001) and Si(111). The atomically resolved images provide invaluable information on heteroepitaxial film growth from the viewpoints of both industrial application and basic science. We briefly review the history of characterizing heteroepitaxial elemental semiconductor systems by means of scanning probe microscopy (SPM), where the Stranski–Krastanov growth mode can be observed on the atomic scale:the detailed phase transition from layer-by-layer growth to three-dimensional cluster growth was elucidated by the use of SPM. In addition, we comment on the potential of SPM for examining the spectroscopic aspects of heteroepitaxial film growth, through the use of SPM tips with well-defined facets.

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