Anisotropic kinetics on growing Ge(0 0 1) surfaces

2013

J Appl Cryst

The results of calculations of reflection high-energy electron diffraction intensities, measured at different stages of the homoepitaxial growth of Ge(001), are described. A two-dimensional Bloch wave approach was used in calculations of the Schrö dinger equation with a one-dimensional potential. The proportional model was used for partially filled layers, i.e. the scattering potential was taken to be proportional to the coverage and the potential of the fully filled layer. Using such an approach, it was shown that it is possible to obtain valuable information for the analysis of experimental data. The results of these calculations were compared with data for off-symmetry azimuths from the literature, and satisfactory agreement between the theoretical and experimental data was found. Also assessed was whether developing more advanced models (i.e. going beyond the proportional model), to make a more detailed account of the diffuse scattering, might be important in achieving a fully quantitative explanation of the experimental data.

Section: Discussionmentioning

confidence: 99%

“…There is currently much interest in the growth of thin layers of Ge(001) and the results of monitoring such growth using RHEED have been published in two recent papers Ohtake et al, 2009). Shin (2007) provides additional information that is of use when studying the results presented in the first of these two papers.…”

Section: Introductionmentioning

confidence: 99%

Computer studies on reflection high-energy electron diffraction from the growing surface of Ge(001)

2013

J Appl Cryst

“…However, it should be said at this occasion that not all experimental results for the growth of Ge layers may be explained employing such modelling. Namely, Ohtake et al [9] observed that during the deposition of Ge atoms, at some temperatures, large anisotropic islands are formed at the surface. Subsequently, the scattering by island steps becomes important, furthermore, it is strongly dependent on the incident beam direction.…”

Section: Discussionmentioning

confidence: 99%

“…Research work is still needed in this area. Recently, there is noticeable interest in growing Ge layers [8,9]. Surprisingly, Shin et al [8] found that for the homoepitaxial growth of Ge, the phase of oscillations for different angles was nearly identical.…”

Section: Introductionmentioning

confidence: 99%

Computer Investigations of Features of RHEED Oscillations for GaAs and for Ge

2013

SSP

During molecular beam epitaxy regular oscillations of the intensity of the specularly reflected beam often occur. The phenomenon of such oscillations is still theoretically explained only partially. For example it is not clear why usually the oscillation phase depends strongly on the glancing angle of the incident beam. However, quite recently interesting results were shown in the literature on the features of RHEED oscillations observed during the growth of Ge layers. The phase of oscillations practically stays constant for a wide range of angles. So in this paper, we show results of RHEED dynamical calculations for Ge. They are presented together with results of calculations for GaAs to make analysis executed more complete. It is concluded that experimental findings for Ge for off-symmetry azimuths can be explained using dynamical diffraction theory employing the proportional model (for which the scattering potential of the layer is determined as the potential of the completed layer multiplied by the coverage).

“…Reflection high-energy electron diffraction (RHEED) is a robust and convenient technique for monitoring the growth of nanostructures at surfaces (Zdyb et al, 2001;Sadowski et al, 2007;Ohtake et al, 2009;Krishnan et al, 2010). Recently, it has been shown that RHEED measurements combined with the use of ultrafast lasers can be applied to the investigation of surface dynamics on femto-and picosecond time scales (Janzen et al, 2006;Liang et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Algorithms for determining the phase of RHEED oscillations

Dudarev

2015

J Appl Cryst

Oscillations of reflection high‐energy electron diffraction (RHEED) intensities are computed using dynamical diffraction theory. The phase of the oscillations is determined using two different approaches. In the first, direct, approach, the phase is determined by identifying the time needed to reach the second oscillation minimum. In the second approach, the phase is found using harmonic analysis. The two approaches are tested by applying them to oscillations simulated using dynamical diffraction theory. The phase of RHEED oscillations observed experimentally is also analysed. Experimental data on the variation of the phase as a function of the glancing angle of incidence, derived using the direct method, are compared with the values computed using both the direct and harmonic methods. For incident‐beam azimuths corresponding to low‐symmetry directions, both approaches produce similar results.