Initial Stages of Growth of Thin Films of III-V Nitrides and Silicon Carbide Polytypes by Molecular Beam Epitaxy

1994 ◽  
Vol 339 ◽  
Author(s):  
Robert F. Davis ◽  
K. S. Ailey ◽  
R. S. Kern ◽  
D. J. Kester ◽  
Z. Sitar ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Three Dimensional ◽  
Layer By Layer ◽  
Interface Chemistry ◽  
Stages Of Growth ◽  
Final Layer ◽  
Metal Evaporation ◽  
Dimensional Growth ◽  
Initial Deposition ◽  
Substrate Surfaces

ABSTRACTThe morphology and interface chemistry occurring during the initial deposition of BN, AlN and GaN films via metal evaporation and N2 decomposition under UHV conditions have been determined. FTIR spectroscopy and TEM revealed the consecutive deposition of an initial 20Å layer of a-BN, 20–60Å of oriented h-BN, and a final layer of polycrystalline c-BN. This sequence is attributed primarily to increasing intrinsic compressive stress in the films. XPS analysis revealed the growth of GaN on sapphire to occur via the Stranski-Krastanov mode; growth on SiC showed characteristics of three-dimensional growth. AlN grew layer-by-layer on both substrates. Vicinal 6H-SiC(0001) substrate surfaces contain closely spaced, single bilayer steps. During deposition of Si and C at 1050°C, 6H layers initially form and step bunching occurs. The latter phenomenon results in more widely spaced steps, the nucleation of 3C-SiC both on the new terraces and at the larger steps and formation of double position boundaries. The C/Si ratio in the gaseous reactants also affects the occurrence of these three phenomena.

Heteroepitaxial Nucleation and Growth of Ge ON Si(100) Surfaces Using Remote Plasma Enhanced Chemical Vapor Deposition

1988 ◽  
Vol 116 ◽  
Author(s):  
R.A. Rudder ◽  
S.V. Hattangady ◽  
D.J. Vitkavage ◽  
R.J. Markunas
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Layer By Layer ◽  
Heteroepitaxial Growth ◽  
Remote Plasma ◽  
Dimensional Growth ◽  
Diffraction Patterns

Heteroepitaxial growth of Ge on Si(100) has been accomplished using remote plasma enhanced chemical vapor deposition at 300*#x00B0;C. Reconstructed surfaces with diffraction patterns showing non-uniform intensity variations along the lengths of the integral order streaks are observed during the first 100 Å of deposit. This observation of an atomically rough surface during the initial stages of growth is an indication of three-dimensional growth. As the epitaxial growth proceeds, the diffraction patterns become uniform with extensive streaking on both the integral and fractional order streaks. Subsequent growth, therefore, takes place in a layer-by-layer, two-dimensional mode. X-ray photoelectron spectroscopy of the early nucleation stages, less than 80 Å, show that there is uniform coverage with no evidence of island formation.

Real-Time X-Ray Scattering Study of Surface Dynamics on Au(111) During Ar+ Ion Irradiation

1998 ◽  
Vol 528 ◽  
Author(s):  
M.V. Ramana Murty ◽  
T. Curcic ◽  
A. Judy ◽  
B.H. Cooper ◽  
A.R. Woll ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Ion Irradiation ◽  
Three Dimensional ◽  
Layer By Layer ◽  
Surface Dynamics ◽  
Surface Evolution ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

AbstractX-ray scattering is used to investigate the surface dynamics on Au(111) during Ar+ ion irradiation. During 500 eV Ar+ ion irradiation, we observe the three regimes of step retraction, quasi-layer-by-layer removal and three dimensional rough erosion, analagous to molecular beam epitaxy. The quasi-layer-by-layer sputtering regime has been studied to identify similarities and differences in surface evolution during ion irradiation and molecular beam epitaxy. X-ray measurements suggest that 500 eV Ar+ ion irradiation does not lead to stable adatom island formation. Also, in contrast to molecular beam epitaxy, adatom detachment and diffusion seems important in describing the surface kinetics during ion irradiation.

Molecular Beam Epitaxy of ZnS Films on Arsenic Passivated Silicon Surfaces

1993 ◽  
Vol 318 ◽  
Author(s):  
Xiaochuan Zhou ◽  
Wiley P. Kirk
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Three Dimensional ◽  
High Energy ◽  
Silicon Surfaces ◽  
Crystalline Quality ◽  
Dimensional Growth ◽  
Initial Adsorption ◽  
Passivated Silicon ◽  
Zns Films

ABSTRACTThe crystalline quality of ZnS films grown on arsenic covered Si(100) surfaces is shown to be improved as compared to films grown on bare silicon surfaces by MBE (molecular beam epitaxy). Employing RGA (residual gas analyzer) and RHEED (reflection high energy electron diffraction) techniques, we found that a strong initial adsorption of sulfur on bare silicon surfaces led to the formation of disordered silicon-sulfide surfaces. This disordered surface initiated three-dimensional growth of ZnS and resulted in poor crystalline quality. An arsenic overlayer was found to be effective in preventing the interaction of sulfur with the silicon surface and thereby maintained surface ordering. X-ray rocking curve analysis indicated higher crystallinity in ZnS films grown on arsenic covered surfaces.

Facet Formation of Lineshaped Silicon Mesas Grown with Micro Shadow Masks

1994 ◽  
Vol 351 ◽  
Author(s):  
H. Gossner ◽  
G. Fehlauer ◽  
W. Kiunke ◽  
I. Eisele ◽  
M. Stolz ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Epitaxial Growth ◽  
Molecular Beam ◽  
Three Dimensional ◽  
Temperature Dependent ◽  
Adatom Diffusion ◽  
Substrate Side ◽  
Side Walls ◽  
Dimensional Growth ◽  
Facet Formation

ABSTRACTAs reported previously, perfect facets can be achieved at the side walls of submicron silicon mesa structures grown by molecular beam epitaxy (MBE) with micro shadow masks [1]. An essentially self organizing, three-dimensional growth was observed. In this paper we present the results of the epitaxial growth on (001) substrates using long (≥ 1μm), lineshaped mask apertures, which put constraints on the formation of facets. At a growth temperature of 500°C {111} facet formation is observed for lineshaped mesas oriented along the <110> direction of the substrate. Side walls with a length of I μm are perfectly plane, while mesas with a length of 10 μm and more show rough sidewalls. This is explained by a limited silicon adatom diffusion on the facet. For higher flux rates the facet formation is suppressed. This can be understood in terms of a reduced adatom diffusion.A crossover from {111} to {113} facet formation is observed at growth temperatures above 500°C. A model for the temperature dependent formation of {111} and {113} facets is given.

The Chemistry and Packaging of Nanocomposite Confined Arrays

1990 ◽  
Vol 206 ◽  
Author(s):  
Galen D. Stucky
Keyword(s):  
Molecular Sieves ◽  
Molecular Beam ◽  
Response Times ◽  
Three Dimensional ◽  
Surface States ◽  
Atomic Layer ◽  
Interface Chemistry ◽  
Transport Efficiency ◽  
Tunable Range ◽  
Cluster Environment

ABSTRACTThe miniaturization of electronic and optic devices has revolutionized response times, energy loss and transport efficiency. An additional bonus is that as one approaches the nanosize regime the presence or absence of a few atoms and the geometrical disposition of each atom can significantly modify electronic and photonic properties. This control can be further supplemented by “packaging” assemblies of atoms or molecules into thin film or nanocomposite bulk materials to define surface states, cluster environment and geometry, intercluster interactions, and consequently, a wide tunable range of optical and charge carrier responses.The chemist is presented with an intriguing challenge. First the clusters must be unisized with identical geometries. Secondly, the atom or molecular assemblies should ideally have perfect periodicity in order to rigorously define optoelectronic densities and intercluster tunnelling. A third requirement is that the nanocomposite be processable, generally in the form of thin films or single crystals. Numerous approaches are being undertaken in achieve these goals, including molecular beam and atomic layer epitaxy, molecular sieve inclusion chemistry, molecular capping of inorganic clusters, porous glass and aerosol synthesis. This paper presents a brief review of the interface chemistry associated with nanophase confinement and packaging and some features of three dimensional surface confinement using molecular sieves and zeolites.

scholarly journals The SiC Single Crystal Growth from Nanomaterial Precursor

MRS Advances ◽  
2019 ◽  
Vol 4 (50) ◽  
pp. 2709-2715
Author(s):  
Yoshimitsu Yamada
Keyword(s):  
Crystal Growth ◽  
Electric Field ◽  
Single Crystal ◽  
Particle Deposition ◽  
Three Dimensional ◽  
Layer Growth ◽  
Seed Crystal ◽  
Layer By Layer ◽  
Remarkable Effect ◽  
Dimensional Growth

ABSTRACTUnlike the conventional layer by layer growth ,three dimensional growth experiments of SiC single crystal by the Chemical Particle Deposition (CPD)method were carried out both on the polar and nonpolar plane of the SiC seed crystal. The comparison of the morphology of the grown crystals on both samples indicated that the electric field formed by the seed crystal strongly effected the diffusion of the supplied Si and C atoms and their compounds to grow the epitaxial crystal. In spite of the low ionicity of Si-C bonds, this remarkable effect of the electric field on the three dimensional crystal growth mechanism in the CPD method strongly suggested its contribution to the ordering of the stacked layers with its long working range, beyond the deformed boundary layers between the seed surface and the grown crystal.

Morphology and Interface chemistry of the Initial Growth of GAN and ALN on α-SIC and Sapphire

1991 ◽  
Vol 237 ◽  
Author(s):  
Z. Sitar ◽  
L. S. Smith ◽  
M. J. Paisley ◽  
R. F. Davis
Keyword(s):  
Molecular Nitrogen ◽  
Three Dimensional ◽  
Plasma Source ◽  
Layer By Layer ◽  
Initial Growth ◽  
Interface Chemistry ◽  
Ecr Plasma ◽  
Gas Source ◽  
Nitride Formation ◽  
Gas Source Mbe

ABSTRACTThe morphology and interface chemistry occurring during the initial stages of growth of GaN and A1N layers has been obtained. Films were grown using gas source MBE equipment containing an ECR plasma source to activate molecular nitrogen. The experiments consisted of sequential depositions of about one monolayer thick films and XPS analysis. Evidence for silicon nitride formation on the SiC surface was obtained from the studies of both the Si oxidation states and the substrate peak intensity dependence on film thickness. The growth of GaN on sapphire appeared to occur via the Stranski-Krastanov mode, while the growth on SiC showed characteristics of three-dimensional growth. AlN grew in a layer-by-layer mode on both substrates.

Molecular Beam Epitaxial Growth of ZnSe, ZnSSe and ZnMnSSe Layers on GaAs Substrates for Blue-Green Laser Structures

1995 ◽  
Vol 417 ◽  
Author(s):  
Y. P. Chen ◽  
M. Saginur ◽  
C. C. Kim ◽  
S. Sivananthan ◽  
D. J. Smith ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Energy Gap ◽  
Three Dimensional ◽  
High Energy ◽  
Green Laser ◽  
Initial Growth ◽  
Molecular Beam Epitaxial ◽  
Gaas Substrates ◽  
Dimensional Growth ◽  
Molecular Beam Epitaxial Growth

AbstractSingle layers of ZnSe, ZnSxSe1−x., and Znl−y.MnySxSe1−x., were grown on the GaAs(001). Realtime reflection high energy electron diffraction was used to study the initial growth of ZnSe(001) on GaAs(001) under different conditions. Exposure of the GaAs substrate to Se flux before growth led to three-dimensional growth, whereas exposure to Zn flux led to two dimensional-growth. ZnSxSe1−x., and Znl−y.MnySxSe1−x., (energy gap less than 2.9 eV) layers with the lattice constant closely matched to that of GaAs have been grown with a good reproducibility.

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