Theoretical analysis of reflection high-energy electron diffraction (RHEED) and reflection high-energy positron diffraction (RHEPD) intensity oscillations expected for the perfect layer-by-layer growth

2015 ◽  
Vol 71 (5) ◽  
pp. 513-518 ◽  
Author(s):  
Zbigniew Mitura
Keyword(s):  
Theoretical Models ◽  
High Energy ◽  
Layer Growth ◽  
Simplified Model ◽  
Layer By Layer ◽  
High Energy Electron ◽  
Realistic Potential ◽  
Simplified Approach ◽  
Electrons And Positrons ◽  
Analytical Formulas

Predictions from two theoretical models, allowing one to determine the phase of intensity oscillations, are compared for reflected beams of electrons and positrons. Namely, results of the precise dynamical calculations are compared with results obtained using a simplified approach. Within the simplified model, changes in the specularly reflected beam intensity, expected to occur during the deposition of new atoms, are described with the help of interfering waves and the effect of refraction, and respective approximate analytical formulas are employed to determine the phase of the oscillations. It is found that the simplified model is very useful for understanding the physics ruling the appearance of intensity oscillations. However, it seems that the model with the realistic potential is more suitable for carrying out interpretations of experimental data.

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.

Reflection High Energy Electron Diffraction Studies of the Growth of DyBa2Cu3O7−x Films and Structures Grown on SrTiO3 Substrates

1992 ◽  
Vol 275 ◽  
Author(s):  
V. S. Achutharaman ◽  
N. Chandrasekhar ◽  
A. M. Goldman
Keyword(s):  
Electron Diffraction ◽  
Specular Reflection ◽  
Growth Conditions ◽  
High Energy ◽  
Layer Growth ◽  
Energy Electron ◽  
Layer By Layer ◽  
High Energy Electron ◽  
Epitaxial Relationship ◽  
Superlattice Structures

ABSTRACTIntensity oscillations of the specular reflection high energy electron diffraction (RHEED) beam contain useful information on the mode of growth and the evolving structure of thin films. We present RHEED studies of the growth of DyBa2Cu3O7−x films and DyBa2Cu3O7−x/DY2O3/DyBa2Cu3O7−x structures on SrTiO3; substrates deposited by ozone-assisted molecular beam epitaxy. The effect of substrate temperature, ozone flux and surface step densities on the epitaxial relationship and evolving microstructure will be discussed. The strong damping of the oscillations and identical time periods under different nuoleation and growth conditions suggest that the intensity oscillations are a consequence of to diffuse scattering from step edges rather than a layer-by-layer growth mode. It was also found that Dy2O3 can be used to fabricatee tri-layer type structures but not superlattice structures.

Auto Feeding Epitaxial Growth of Oxide Thin Film without Oxidant

2001 ◽  
Vol 666 ◽  
Author(s):  
Kazuo Shimoyama ◽  
Kousuke Kubo ◽  
Tatsuro Maeda ◽  
Kikuo Yamabe
Keyword(s):  
Molecular Beam ◽  
Oxygen Supply ◽  
High Energy ◽  
Layer Growth ◽  
Oxide Thin Film ◽  
Layer By Layer ◽  
High Energy Electron ◽  
Low Oxygen ◽  
High Quality ◽  
Deposited Films

ABSTRACTHigh-quality thin films of BaTiO3 and SrTiO3 on SrTiO3 substrate were obtained by shutting off the oxygen supply during growth. Epitaxial growths were carried out with molecular-beam epitaxy (MBE) under extremely low oxygen partial pressure (pO2 < 1×10−8 Pa). Although only Ba(Sr) and Ti metals were supplied without introducing oxidant during the growth, clear reflection high-energy electron diffraction (RHEED) intensity oscillations from layer-by-layer growth were observed. The deposited films were found to have approximately stoichiometric compositions of BaTiO3 and SrTiO3. Oxygen was automatically fed from the substrate during the growths. It was found that the BaTiO3/SrTiO3 interface was abrupt without intermixing, despite a considerable amount of oxygen seems to have moved from the substrate to the film through the interface.

EFFECT OF Bi SURFACTANT IN THE HETEROEPITAXIAL GROWTH OF Co ON Cu SURFACES

2006 ◽  
Vol 13 (02n03) ◽  
pp. 201-207 ◽  
Author(s):  
MASAO KAMIKO ◽  
HIROAKI CHIHAYA ◽  
WATARU SUGIMOTO ◽  
RYOICHI YAMAMOTO ◽  
SANGMUN OH ◽  
...  
Keyword(s):  
Electron Spectroscopy ◽  
Surface Segregation ◽  
High Energy ◽  
Layer Growth ◽  
Layer By Layer ◽  
High Energy Electron ◽  
Heteroepitaxial Growth ◽  
Segregation Effect ◽  
Suitable Amount ◽  
Layered Growth

We have investigated the effect of Bi on the heteroepitaxial growth of Co on Cu by reflection high-energy electron diffraction (RHEED) measurements. It was found that Bi enhanced the layer-by-layer growth of Co on the Cu (111) surfaces at 100°C. The dependence of the growth on Bi layer thickness suggested that there existed a suitable amount of Bi surfactant layer that enhanced smoother layered growth. On the contrary, for the case of Co growth on Cu (100), Bi depressed the layer-by-layer growth of Co on Cu (100). The surface segregation effect of Bi was also studied by Auger electron spectroscopy (AES).

Combinatorial Molecular Layer Epitaxy of Hf Based Phosphor Oxides

2001 ◽  
Vol 700 ◽  
Author(s):  
N. Arai ◽  
T. W. Kim ◽  
H. Kubota ◽  
Y. Matsumoto ◽  
H. Koinuma
Keyword(s):  
Molecular Layer ◽  
High Energy ◽  
Layer Growth ◽  
Laser Deposition ◽  
Layer By Layer ◽  
High Energy Electron ◽  
X Ray ◽  
Substrate Interaction ◽  
Film Substrate

AbstractA series of MHfO3: Tm (M =Ca, Sr and Ba) composition spread films and superlattices (SLs) were quickly fabricated on SrTiO3 (001) substrate in the molecular layer-by-layer growth using combinatorial pulsed laser deposition (PLD) under in-situ reflection high-energy electron diffraction (RHEED) monitoring. Crystal structures and luminescence properties of composition-spread and SLs were evaluated by the concurrent X-ray diffractometer and cathode luminescence (CL), respectively. CL properties of the films were found strongly dependent on their composition and stacking sequence. Possible effect of the stress due to the film-substrate interaction on the CL property is discussed.

Hopping Barriers at Step Edges

1993 ◽  
Vol 312 ◽  
Author(s):  
Pavel Šmilauer ◽  
Mark R. Wilby ◽  
Dimitri D. Vvedensky
Keyword(s):  
High Energy ◽  
Layer Growth ◽  
Low Energy ◽  
Step Edge ◽  
Solid Model ◽  
Layer By Layer ◽  
Ion Sputtering ◽  
High Energy Electron ◽  
Diffraction Intensity ◽  
Good Agreement

AbstractThe recent discovery of reentrant layer-by-layer growth in metal homoepitaxy has stimulated considerable interest in the role played by barriers to hopping down descending steps. However, the existence of step-edge barriers for semiconductors is far from being clearly established. We have investigated the effects of step-edge barriers for epitaxial growth and the “inverse” process of low-energy ion sputtering on metal surfaces using Monte Carlo simulations of a solid-on-solid model. Our results are in good agreement with available experimental data and provide new insights into the microscopic origins of the evolution of surface morphology during these processes. Our simulations also suggest that such step-edge barriers can explain the observed temperature and time dependence of the reflection high-energy electron diffraction intensity during post-growth recovery on GaAs(001), which sheds new light on this controversial subject.

Atomic Layer and Unit-Cell Layer Growth of (Ca,Sr)CuO2 and Bi2Sr2Can-1CunO2n+4 Thin Films by Laser Molecular Bean Epitaxy

1991 ◽  
Vol 222 ◽  
Author(s):  
Masaki Kanai ◽  
Tomoji Kawai ◽  
Takuya Matsumoto ◽  
Shichio Kawai
Keyword(s):  
Thin Films ◽  
Diffraction Pattern ◽  
Cell Layer ◽  
Atomic Layer ◽  
High Energy ◽  
Layer Growth ◽  
Unit Cell ◽  
Layer By Layer ◽  
Diffraction Intensity

ABSTRACTThin films of (Ca,Sr)CuO2 and Bi2Sr2Can-1CunO2n+4 are formed by laser molecular beam epitaxy with in-situ reflection high energy electron diffraction observation. The diffraction pattern shows that these materials are formed with layer-by-layer growth. The change of the diffraction intensity as well as the analysis of the total diffraction pattern makes It possible to control the grown of the atomic layer or the unit-cell layer.

Rheed Intensity Oscillation During Layer-by-Layer Growth of Bi-Sr-Ca-Cu-O Thin Films

1992 ◽  
Vol 275 ◽  
Author(s):  
K. Yoshikawa ◽  
N. Sasaki
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
High Energy ◽  
Layer Growth ◽  
Layer By Layer ◽  
Two Dimensional ◽  
Growth Interruption ◽  
Layer Deposition ◽  
Unit Cells ◽  
Layered Growth

ABSTRACTUsing in-situ reflection high-energy electron diffraction (RHEED), we studied the growth of Bi-Sr-Ca-Cu-O (BSCCO) thin films prepared by reactive evaporation using layer-by-layer deposition. Bi2Sr2CaCu2Ox(2212) tends to be grown three-dimensionally if it is grown directly on (100) SrTiO3, in contrast to Bi2Sr2CuOx(2201) which is easily grown two-dimensionally on SrTiO3. Two-dimensional 2212 growth can be realized, if a buffer layer of 2201 is deposited on (100) SrTiO3 and growth interruption is utilized after SrO layer deposition. A buffer layer of only two 2201 unit cells improved the surface crystallinity of the substrate for the epitaxial growth of 2212. Growth interruption for two minutes after the 2nd SrO layer in the half unit cell is necessary to keep two-dimensional layered growth. The resulting Tc (zero) is 76 K and Jc (at 4.2 K) is 1.5 × 106 (A/cm2) with these epitaxial films.

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.

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