An In-Situ Study of the Segregation and the Strain Relaxation During Growth of Gold and Nickel Ultrathin Films

1999 ◽  
Vol 562 ◽  
Author(s):  
S. Labat ◽  
P. Gergaud ◽  
O. Thomas ◽  
B. Gilles ◽  
A. Marty
Keyword(s):  
Ultrathin Films ◽  
Strain Relaxation ◽  
High Energy ◽  
Stress And Strain ◽  
High Energy Electron ◽  
In Situ Study ◽  
Real Time Measurement ◽  
Ultrathin Layers ◽  
Large Asymmetry

ABSTRACTWe report on in-situ real time measurement of both stress and strain during growth of ultrathin layers, with submonolayer sensitivity. The in-plane parameter is measured by Reflection High Energy Electron Diffraction (RHEED) and the stress is determined via the measurement of the curvature. The system studied is Au/Ni (i.e. Au on Ni and Ni on Au). We have evidenced a large asymmetry in the two different growths: Au (on Ni) shows a progressive elastic strain relaxation whereas Ni (on Au) exhibits a strong interplay between the stress and the interfacial mixing.

In-Situ Study of the Oxide Mediated Epitaxy of CoSi2 on Si

1999 ◽  
Vol 564 ◽  
Author(s):  
M. W. Kleinschmit ◽  
M. Yeadon ◽  
J. M. Gibson
Keyword(s):  
Silicon Surface ◽  
High Vacuum ◽  
High Energy ◽  
Ultra High Vacuum ◽  
High Energy Electron ◽  
In Situ Study ◽  
Intermediate Phases ◽  
Transmission Electron ◽  
Combined Imaging

AbstractOxide Mediated Epitaxy (OME) shows promise as a method to form good quality, thin epitaxial CoSi2 films on most Si surfaces. We have performed an in-situ study of the OME of CoSi2, on the Si (001) surface. Our work was carried out with our specially modified ultra-high vacuum transmission electron microscope (UHV TEM) SHEBA (Surface High Energy Electron Beam Apparatus). With SHEBA we were able to monitor the diffraction pattern and therefore the phase formation throughout the anneal. Our results confirm the suppression of intermediate phases during CoSi2 formation in the OME process. We also see a difference in the as deposited Co film when the oxide coated silicon surface is used rather than a clean substrate. From combined imaging and diffraction studies we will shed some light on the mechanism behind the success of OME.

scholarly journals Evidence of 2D-3D transition during the first stages of GaN growth on AlN

1997 ◽  
Vol 2 ◽  
Author(s):  
F. Widmann ◽  
B. Daudin ◽  
G. Feuillet ◽  
Y. Samson ◽  
M. Arlery ◽  
...  
Keyword(s):  
Smooth Surface ◽  
Molecular Beam ◽  
Growth Parameters ◽  
Strain Relaxation ◽  
Relaxation Mechanism ◽  
High Energy ◽  
Rheed Pattern ◽  
High Energy Electron ◽  
Island Coalescence

In order to identify the strain relaxation mechanism, Molecular Beam Epitaxy of wurtzite GaN on AlN was monitored in situ using Reflection High Energy Electron Diffraction (RHEED). In the substrate temperature range between 620°C and 720°C, a Stransky-Krastanov (SK) transition was evidenced, resulting in a 2D-3D transition after completion of 2 monolayers, with subsequent coalescence of 3D islands, eventually resulting in a smooth surface. Quantitative analysis of the RHEED pattern allowed us to determine that island formation is associated with elastic relaxation. After island coalescence, a progressive plastic relaxation is observed. The size and density of 3D islands was varied as a function of the growth parameters. AFM experiments revealed that the size of the GaN islands, about 8 nm large and 2 nm high, was small enough to expect quantum effects. It was found that capping of the islands by AlN resulted in a smooth surface after deposition of a few monolayers allowing us to grow a »superlattice» of islands by periodically repeating the process.

Epitaxial growth manner and structure of superconducting oxide films

1990 ◽  
Vol 48 (4) ◽  
pp. 2-3
Author(s):  
Yoshichika Bando ◽  
Takahito Terashima ◽  
Kenji Iijima ◽  
Kazunuki Yamamoto ◽  
Kazuto Hirata ◽  
...  
Keyword(s):  
Ultrathin Films ◽  
Film Surface ◽  
High Energy ◽  
Epitaxial Films ◽  
Layer By Layer ◽  
Initial Growth ◽  
In Situ Growth ◽  
High Quality ◽  
Activated Reactive Evaporation

The high quality thin films of high-Tc superconducting oxide are necessary for elucidating the superconducting mechanism and for device application. The recent trend in the preparation of high-Tc films has been toward “in-situ” growth of the superconducting phase at relatively low temperatures. The purpose of “in-situ” growth is to attain surface smoothness suitable for fabricating film devices but also to obtain high quality film. We present the investigation on the initial growth manner of YBCO by in-situ reflective high energy electron diffraction (RHEED) technique and on the structural and superconducting properties of the resulting ultrathin films below 100Å. The epitaxial films have been grown on (100) plane of MgO and SrTiO, heated below 650°C by activated reactive evaporation. The in-situ RHEED observation and the intensity measurement was carried out during deposition of YBCO on the substrate at 650°C. The deposition rate was 0.8Å/s. Fig. 1 shows the RHEED patterns at every stage of deposition of YBCO on MgO(100). All the patterns exhibit the sharp streaks, indicating that the film surface is atomically smooth and the growth manner is layer-by-layer.

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