Rapid heteroepitaxial growth of Ge films on (100) GaAs by pulsed supersonic free‐jet chemical beam epitaxy

1989 ◽  
Vol 55 (10) ◽  
pp. 1008-1010 ◽  
Author(s):  
Djula Eres ◽  
Douglas H. Lowndes ◽  
Jon Z. Tischler
Keyword(s):  
Chemical Beam Epitaxy ◽  
Heteroepitaxial Growth ◽  
Free Jet

scholarly journals Heteroepitaxial Growth of Germanium Films by Supersonic Free Jet Chemical Beam Epitaxy

1989 ◽  
Vol 160 ◽  
Author(s):  
Djula Eres ◽  
J. W. Sharp ◽  
D. H. Lowndes
Keyword(s):  
Continuous Wave ◽  
Film Growth ◽  
Substrate Surface ◽  
Thickness Distribution ◽  
Chemical Beam Epitaxy ◽  
Heteroepitaxial Growth ◽  
Free Jet ◽  
Si Substrates ◽  
Pulsed Mode ◽  
Background Gas

AbstractA supersonic free jet operated in continuous wave and pulsed mode was used to grow Ge films on (100) GaAs and (100) Si substrates. The Ge-bearing source molecule digermane (Ge2H6) was seeded (at 5% concentration) in a helium carrier gas. A free jet expansion of this gas mixture was directed toward the heated substrate surface, where Ge film growth took place by surface-induced thermal decomposition of the ballistically impinging digermane molecules. The thickness distribution across the substrate surface was fitted by a cosmJ distribution. The values of m spanned the range 6–35. The upper limit on growth resulting from “background” gas scattered out of the jet was found to be less than 10% of the Ge film thickness for growth on (100) GaAs, and around 25% for growth on (100) Si.

Epitaxial Variants and Grain Boundary Structures in Heteroepitaxial Lithium Tantalate on Basal Sapphire

1996 ◽  
Vol 441 ◽  
Author(s):  
Robert A. Bellman ◽  
Rishi Raj
Keyword(s):  
Grain Boundary ◽  
Stoichiometric Composition ◽  
Lithium Tantalate ◽  
Grain Structure ◽  
Chemical Beam Epitaxy ◽  
Heteroepitaxial Growth ◽  
Crystalline Perfection ◽  
Electro Optic ◽  
Optical Applications ◽  
High Degree

AbstractSingle crystal heteroepitaxial ferroelectric films are desired for non-linear optical applications to maximize the electro-optic coefficient and minimize waveguide losses. In this study, lithium tantalate films were deposited on (0001) sapphire from lithium hexaethoxytantalate by chemical beam epitaxy. Characterization showed that films had nearly stoichiometric composition, epitaxial orientation, and a high degree of crystalline perfection. However, the films exhibited high optical waveguide losses. Additional characterization by TEM revealed that the films had a two dimensional grain structure with epitaxial variants related by translation and a twin orientation to the substrate. To better understand the nature of the heteroepitaxial growth of lithium tantalate on (0001) sapphire, a model was developed to explain the observed epitaxial orientations, misfit dislocation networks, and grain boundary structures of lithium tantalate on (0001) sapphire.

Production and STEM examination of controlled-size silver clusters

1983 ◽  
Vol 41 ◽  
pp. 338-339
Author(s):  
M. A. Listvan ◽  
R. P. Andres
Keyword(s):  
Cluster Size ◽  
Metal Clusters ◽  
Experimental Parameter ◽  
Carbon Films ◽  
Metal Species ◽  
Silver Clusters ◽  
Free Jet ◽  
Size Dependent ◽  
Cluster Properties ◽  
Controllable Size

Knowledge of the function and structure of small metal clusters is one goal of research in catalysis. One important experimental parameter is cluster size. Ideally, one would like to produce metal clusters of regulated size in order to characterize size-dependent cluster properties.A source has been developed which is capable of producing microscopic metal clusters of controllable size (in the range 5-500 atoms) This source, the Multiple Expansion Cluster Source, with a Free Jet Deceleration Filter (MECS/FJDF) operates as follows. The bulk metal is heated in an oven to give controlled concentrations of monomer and dimer which were expanded sonically. These metal species were quenched and condensed in He and filtered to produce areosol particles of a controlled size as verified by mass spectrometer measurements. The clusters were caught on pre-mounted, clean carbon films. The grids were then transferred in air for microscopic examination. MECS/FJDF was used to produce two different sizes of silver clusters for this study: nominally Ag6 and Ag50.

Electron microscopic characterization of diamond thin films and substrates for diamond heteroepitaxial growth

1989 ◽  
Vol 47 ◽  
pp. 592-593
Author(s):  
J.B. Posthill ◽  
R.P. Burns ◽  
R.A. Rudder ◽  
Y.H. Lee ◽  
R.J. Markunas ◽  
...  
Keyword(s):  
Thin Films ◽  
Wide Band ◽  
Deposition Process ◽  
Heteroepitaxial Growth ◽  
Electron Microscopic ◽  
Wide Band Gap ◽  
Lattice Matching ◽  
Different Types ◽  
Diamond Thin Films

Because of diamond’s wide band gap, high thermal conductivity, high breakdown voltage and high radiation resistance, there is a growing interest in developing diamond-based devices for several new and demanding electronic applications. In developing this technology, there are several new challenges to be overcome. Much of our effort has been directed at developing a diamond deposition process that will permit controlled, epitaxial growth. Also, because of cost and size considerations, it is mandatory that a non-native substrate be developed for heteroepitaxial nucleation and growth of diamond thin films. To this end, we are currently investigating the use of Ni single crystals on which different types of epitaxial metals are grown by molecular beam epitaxy (MBE) for lattice matching to diamond as well as surface chemistry modification. This contribution reports briefly on our microscopic observations that are integral to these endeavors.

Chemical and Electrochemical Heteroepitaxial Growth of Chalcogenide Semiconductors from Solutions

1996 ◽  
Vol 451 ◽  
Author(s):  
D. Lincot ◽  
M. J. Furlong ◽  
M. Froment ◽  
R. Cortes ◽  
M. C. Bernard
Keyword(s):  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
Basic Principles ◽  
Lattice Match ◽  
X Ray ◽  
Chalcogenide Semiconductors ◽  
Influence Of Temperature On ◽  
Deposition Processes ◽  
A Site ◽  
Site Selective

ABSTRACTChalcogenide semiconductors have been deposited epitaxially from aqueous solutions either chemically or electrochemically at growth rates of up to 0.7 μmhr−1. After recalling the basic principles of these deposition processes, results are presented concerning chemically deposited CdS on InP, GaP and CuInSe2 substrates, electrodeposited CdTe on InP, and CdSAnP heterostructures. Characterisation of these structures by RHEED, TEM, HRTEM, and glazing angle X ray diffraction allows to analyse the effects of substrate orientation, polarity, lattice match plus the influence of temperature on epitaxial growth. These results are discussed in terms of self organisation and a site selective growth mechanisms due to the free enegy of formation of each compound.

Simulations of a Turbulent Free Jet

2014 ◽  
Vol 8 (5) ◽  
pp. 820
Author(s):  
Saad Ahmed ◽  
Bharath Raghavan
Keyword(s):  
Free Jet

Free-jet expansions from laser-vaporized planar surfaces

1976 ◽  
Author(s):  
M. COVINGTON ◽  
G. LIU ◽  
K. LINCOLN
Keyword(s):  
Free Jet ◽  
Planar Surfaces
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