scholarly journals Beating in the RHEED Intensity Oscillations during Surfactant Mediated GaAs Molecular Beam Epitaxy: Process Physics and Modeling

VLSI Design ◽  
1998 ◽  
Vol 6 (1-4) ◽  
pp. 405-408
Author(s):  
Vamsee K. Pamula ◽  
R. Venkat
Keyword(s):  
Molecular Beam ◽  
Flux Ratio ◽  
High Energy ◽  
Equation Model ◽  
High Energy Electron ◽  
Fixed Temperature ◽  
Mbe Growth ◽  
Molecular Beam Epitaxial ◽  
Monolayer Coverage ◽  
Period Of Oscillation

In a recent work, beating in the reflection high energy electron diffraction (RHEED) intensity oscillations were observed during molecular beam epitaxial (MBE) growth of GaAs with Sn as a surfactant. The strength of beating is found to be dependent on the Sn submonolayer coverage with strong beating observed for 0.4 monolayer coverage. For a fixed temperature and flux ratio (Ga to As), the period of oscillation decreases with increasing Sn coverage. In this work, we have developed a rate equation model of growth to investigate this phenomenon. In our model, the GaAs covered by the Sn is assumed to grow at a faster rate compared to the GaAs not covered by Sn. Assuming that the electron beams reflected from the Sn covered surface and the rest of the surface are incoherent, the results of the dependence of the RHEED oscillations on Sn submonolayer coverages for various Sn coverages were obtained and compared with experimental data and the agreement is good.

The surface structure of GaAs(100) studied by RHEED and REM

1990 ◽  
Vol 48 (4) ◽  
pp. 626-627
Author(s):  
Tung Hsu ◽  
G.S. Petrich ◽  
P. I. Cohen
Keyword(s):  
Molecular Beam ◽  
Flux Ratio ◽  
High Energy ◽  
Ex Situ ◽  
High Energy Electron ◽  
Grown Film ◽  
Mbe Growth ◽  
Different Types ◽  
Reflection Electron Microscopy

Three GaAs( 100) samples, each grown on a differently misoriented GaAs( 100) substrate, were prepared using molecular beam epitaxy (MBE) and characterized by in situ reflection high energy electron diffraction (RHEED) and ex situ RHEED and reflection electron microscopy (REM): A: the substrate is 2° off the (100) toward [011] (A misorientation),B: the substrate is 2° off the (100) toward (B misorientation), andC: the substrate is within 0.1° of (100) (Fig. 1).The goals were to compare the effects of MBE growth and oxidation on the different types of steps formed on these surfaces. Understanding the processes involved in promoting ordering of terrace lengths, and reduction of meandering and step bunching is crucial to current attempts to fabricate quantum wire structures.Samples were prepared by chemically etching the substrates and then growing 0.2μm of GaAs at 600°C, at a rate of 0.4μm/h, and using a 3:1 As:Ga flux ratio. Shapes of the in situ RHEED spots were used to measure the step configuration while the oscillation of RHEED intensities was used to determine the thickness of the grown film.

Surface Reconstruction of MBE-Grown GeXSi1−x on Si(111)

1987 ◽  
Vol 102 ◽  
Author(s):  
C. F. Huang ◽  
R. P. G. Karunasiri ◽  
J. S. Park ◽  
K. L. Wang ◽  
T. W. Kang
Keyword(s):  
Molecular Beam Epitaxy ◽  
Electron Diffraction ◽  
Raman Scattering ◽  
Surface Reconstruction ◽  
Molecular Beam ◽  
Critical Thickness ◽  
High Energy ◽  
High Energy Electron ◽  
Mbe Growth ◽  
Strain Layer

ABSTRACTSurface reconstruction during the molecular beam epitaxy (MBE) growth of GexSi1−x ( x = 0.2 - 1.0 ) film on Si(111) was studied using reflection high energy electron diffraction (RHEED). A series of reconstruction pattern transitions was observed due to the formation of strain layer and its relaxation. The critical thickness obtained using the thickness of the GexSil-x film at the transition of the reconstruction pattern agrees well with the previously reported values. The strain dependence of RHEED patterns for GexSi1−x film was substantiated by Raman scattering.

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