scholarly journals Structure and Electron Mobility of ScN Films Grown on α-Al2O3(1 1 ¯ 02) Substrates

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2449 ◽  
Author(s):  
Takeshi Ohgaki ◽  
Isao Sakaguchi ◽  
Naoki Ohashi
Keyword(s):  
Growth Temperature ◽  
Hall Mobility ◽  
Film Growth ◽  
Growth Conditions ◽  
Growth Direction ◽  
Heteroepitaxial Growth ◽  
Scandium Nitride ◽  
Nonstoichiometric Composition ◽  
Orientation Anisotropy ◽  
Α Al2o3

Scandium nitride (ScN) films were grown on α-Al2O3( 1 1 ¯ 02 ) substrates using the molecular beam epitaxy method, and the heteroepitaxial growth of ScN on α-Al2O3( 1 1 ¯ 02 ) and their electric properties were studied. Epitaxial ScN films with an orientation relationship (100)ScN || ( 1 1 ¯ 02 )α-Al2O3 and [001]ScN || [ 11 2 ¯ 0 ]α-Al2O3 were grown on α-Al2O3( 1 1 ¯ 02 ) substrates. Their crystalline orientation anisotropy was found to be small. In addition, [100] of the ScN films were tilted along [ 1 ¯ 101 ] of α-Al2O3( 1 1 ¯ 02 ) in the initial stage of growth. The tilt angle between the film growth direction and [100] of ScN was 1.4–2.0° and increased with growth temperature. The crystallinity of the ScN films also improved with the increasing growth temperature. The film with the highest Hall mobility was obtained at the boundary growth conditions determined by the relationship between the crystallinity and the nonstoichiometric composition because the film with the highest crystallinity was obtained under the Sc-rich growth condition. The decreased Hall mobility with a simultaneous improvement in film crystallinity was caused by the increased carrier scattering by the ionized donors originating from the nonstoichiometric composition.

Growth Chemistry of Nanocrystalline Si:H Films

2005 ◽  
Vol 862 ◽  
Author(s):  
Vikram L. Dalal ◽  
Kamal Muthukrishnan ◽  
Daniel Stieler ◽  
Max Noack
Keyword(s):  
Grain Size ◽  
Growth Temperature ◽  
Growth Conditions ◽  
Growth Direction ◽  
Natural Growth ◽  
Hot Wire ◽  
Plasma Cvd ◽  
Random Nucleation ◽  
Hydrogen Dilution ◽  
Increasing Temperature

AbstractWe report on the growth of nanocrystalline Si:H films using both plasma CVD and remote hot wire deposition under systematically varied growth conditions. The films were grown from mixtures of silane and hydrogen. It was found that when the films were grown under low pressure VHF plasma growth conditions, the orientation of the film changed as the pressure increased. At the lowest pressures, the films were mainly <111> oriented, but changed to <220> orientation as the pressure increased. The grain size increased as the growth temperature increased. When the films were grown using remote hot wire deposition, the orientation depended upon both hydrogen dilution and growth temperature. As the hydrogen dilution increased, the <220> grain size became smaller. Grain size as large as 36 nm was obtained by controlling the growth conditions in hot wire deposition. As the growth temperature increased, the size of <220> grains increased. Growth rates also increased with increasing temperature. The data can be explained by invoking a growth model which recognizes that the natural growth direction for Si is <220>, since the surface energy is highest for (220) plane. Random nucleation leads to <220> grains. Bonded H is believed to inhibit the growth of <220> grains.

scholarly journals Heteroepitaxial Growth of Ge Nanowires on Si Substrates

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Pietro Artoni ◽  
Alessia Irrera ◽  
Emanuele Francesco Pecora ◽  
Simona Boninelli ◽  
Corrado Spinella ◽  
...  
Keyword(s):  
Electron Beam ◽  
Lower Energy ◽  
Growth Conditions ◽  
Growth Direction ◽  
Electron Beam Evaporation ◽  
Heteroepitaxial Growth ◽  
Au Catalyst ◽  
Electron Microscopies ◽  
Si Substrates ◽  
Transmission Electron

Electron beam evaporation has been used to prepare Ge nanowires (NWs) on top of (111) Si substrates. Despite the non-UHV growth conditions, scanning and transmission electron microscopies demonstrate that NWs are single crystal with specific crystallographic growth directions ([111], [110], and [112]). NWs are faceted, exhibiting the lower energy plans on the surface. The faceting depends on the growth direction. Moreover, the detrimental effects for Ge NWs growth of O atoms contamination are discussed. Finally, we describe how a proper preparation of the Au catalyst is able to increase the Ge NW density by a factor of 4, while heteroepitaxy and faceting features are maintained.

Microstructure of TiO2 rutile thin films deposited on (110) α−Al2O3

1991 ◽  
Vol 6 (11) ◽  
pp. 2417-2426 ◽  
Author(s):  
Y. Gao ◽  
K.L. Merkle ◽  
H.L.M. Chang ◽  
T.J. Zhang ◽  
D.J. Lam
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Grain Boundaries ◽  
Film Growth ◽  
Lattice Mismatch ◽  
High Resolution Electron Microscopy ◽  
Growth Direction ◽  
Orientation Relationships ◽  
Atomic Structures ◽  
Α Al2o3

TiO2 rutile thin films grown on (110) sapphire (α−Al2O3) by the MOCVD technique have been characterized by transmission electron microscopy (TEM) and high resolution electron microscopy (HREM). The TiO2 rutile thin films grew on the sapphire with two epitaxial orientations. The epitaxial orientation relationships between the rutile films (R) and the sapphire substrate (S) were found to be (1) (101)[010]R ‖ (110)[0001]s. Detailed atomic structures of near-interface regions have been investigated by HREM, providing a clear picture of the initial stage of film growth. HREM images show that about 70% of the nuclei at the interface are the (101) rutile, but most of them are very small, about 5 nm (or 2% of the film thickness) in the growth direction. The film growth was dominated by the (200) orientation. Nucleation and growth of the films will be discussed in terms of the lattice mismatch at the interface and growth rates along the two orientations. Planar defects such as twin boundaries and special grain boundaries are commonly observed in the films, especially in regions close to the substrate. The twin plane and twinning direction are {101} and 〈101〉, respectively. Special grain boundaries are found to be correlated with nucleation and twinning.

scholarly journals Growth of NbO2 by Molecular-Beam Epitaxy and Characterization of its Metal-Insulator Transition

MRS Advances ◽  
2017 ◽  
Vol 2 (52) ◽  
pp. 3031-3036 ◽  
Author(s):  
Lindsey E. Noskin ◽  
Ariel Seidner H. ◽  
Darrell G. Schlom
Keyword(s):  
Electrical Resistivity ◽  
Molecular Beam Epitaxy ◽  
Growth Temperature ◽  
Molecular Beam ◽  
Film Growth ◽  
Growth Parameters ◽  
Growth Conditions ◽  
Lower Growth ◽  
Rutile Structure ◽  
Partial Pressures

ABSTRACTThin films of NbO2 are synthesized by oxide molecular-beam epitaxy on (001) MgF2 substrates, which are isostructural (rutile structure) with NbO2. Two growth parameters are systematically varied in order to identify appropriate growth conditions: growth temperature and the partial pressure of O2 during film growth. θ-2θ X-ray diffraction measurements identify two dominant phases in this system at background oxygen pressures in the (0.2–6)×10–7 Torr range: rutile NbO2 is favored at higher growth temperature, while Nb2O5 forms at lower growth temperature. Electrical resistivity measurements were made between 350 K and 675 K on three epitaxial NbO2 films in a nitrogen ambient. These measurements show that NbO2 films grown in higher partial pressures of molecular oxygen have larger temperature-dependent changes in electrical resistivity and higher resistivity at room temperature.

Strain in 3C–SiC Heteroepitaxial Layers Grown on (100) and (111) Oriented Silicon Substrates

2008 ◽  
Vol 600-603 ◽  
pp. 207-210 ◽  
Author(s):  
Marcin Zielinski ◽  
Marc Portail ◽  
Thierry Chassagne ◽  
Yvon Cordier
Keyword(s):  
Gaseous Phase ◽  
Growth Temperature ◽  
Growth Conditions ◽  
Silicon Substrates ◽  
Phase Growth ◽  
Growth Duration ◽  
Strain Control ◽  
Heteroepitaxial Layers ◽  
Oriented Layers ◽  
Sic Films

We discuss the influence of the growth conditions (composition of the gaseous phase, growth duration, growth temperature) and wafer properties (orientation, miscut, thickness) on the residual strain of 3C-SiC films grown on silicon substrates. We show that the strain related effects are observed for both studied orientations however some of them (namely the creep effects) were up to now stated only for (100) oriented layers. We also point out the main difference in strain control between the (111) and (100) orientations.

Heteroepitaxial growth of 3C–SiC film on Si(100) substrate by plasma chemical vapor deposition using monomethylsilane

2007 ◽  
Vol 22 (5) ◽  
pp. 1275-1280 ◽  
Author(s):  
Y. Morikawa ◽  
M. Hirai ◽  
A. Ohi ◽  
M. Kusaka ◽  
M. Iwami
Keyword(s):  
Chemical Vapor Deposition ◽  
Substrate Temperature ◽  
Single Molecule ◽  
Vapor Deposition ◽  
Film Growth ◽  
Chemical Vapor ◽  
Heteroepitaxial Growth ◽  
Plasma Chemical ◽  
Plasma Chemical Vapor Deposition ◽  
Sic Film

We have studied the heteroepitaxial growth of 3C–SiC film on an Si(100) substrate by plasma chemical vapor deposition using monomethylsilane, a single-molecule gas containing both Si and C atoms. We have tried to introduce an interval process, in which we decrease the substrate temperature for a few minutes at a suitable stage of film growth. It was expected that, during the interval process, stabilization such as desorption of nonreacted precursors and lateral diffusion of species produced at the initial stage of film growth would occur. From the results, it appears that the interval process using a substrate temperature of 800 °C effectively suppresses polycrystallization of 3C–SiC growth on the Si(100) surface

The Influence of the Carbonization Mechanisms on the Crystalline Quality of the Carbonization Layer for Heteroepitaxial Growth of 3C-SiC

2014 ◽  
Vol 778-780 ◽  
pp. 230-233
Author(s):  
Yukimune Watanabe ◽  
Tsuyoshi Horikawa ◽  
Kiichi Kamimura
Keyword(s):  
Diffusion Mechanism ◽  
Growth Direction ◽  
Crystalline Quality ◽  
Process Conditions ◽  
Heteroepitaxial Growth ◽  
Crystal Axis ◽  
Si Substrates ◽  
Selected Area Electron Diffraction ◽  
Better Than

The carbonized layer for a buffer layer strongly influences the crystalline quality of the 3C-SiC epitaxial films on the Si substrates. The growth mechanism of the carbonized layer strongly depended on the process conditions. The surface of silicon substrate was carbonized under the pressure of 7.8 × 10-3 Pa or 7.8 × 10-2 Pa in this research. Under the relatively low pressure of 7.8 × 10-3 Pa, the carbonized layer was grown by the epitaxial mechanism. The crystal axis of the carbonized layer grown under this pressure was confirmed to coincide with the crystal axis of the Si substrate from the results of the selected area electron diffraction (SAED) analysis. Under the relatively high pressure condition of 7.8 × 10-2 Pa, the carbonized layer was grown by the diffusion mechanism. The result of the SAED pattern and the XTEM image indicated that this layer consisted of small grainy crystals and their crystal axes inclined against the growth direction. It was confirmed that the crystalline quality of the SiC film deposited on the carbonized layer grown by the epitaxial mechanism is better than that deposited on the layer grown by the diffusion mechanism.

scholarly journals Characterisation of III?V Multilayers Grown by Low-pressure Metal Organic Vapour-phase Epitaxy

1993 ◽  
Vol 46 (3) ◽  
pp. 435
Author(s):  
C Jagadish ◽  
A Clark ◽  
G Li ◽  
CA Larson ◽  
N Hauser ◽  
...  
Keyword(s):  
Gallium Arsenide ◽  
Growth Temperature ◽  
Deep Level ◽  
Growth Parameters ◽  
Low Pressure ◽  
Vapour Phase ◽  
Growth Conditions ◽  
Vapour Phase Epitaxy ◽  
Metal Organic ◽  
Organic Vapour

Undoped and doped layers of gallium arsenide and aluminium gallium arsenide have been grown on gallium arsenide by low-pressure metal organic vapour-phase epitaxy (MOVPE). Delta doping and growth on silicon substrates have also been attempted. Of particular interest in the present study has been the influence of growth parameters, such as growth temperature, group III mole fraction and dopant flow, on the electrical and physical properties of gallium arsenide layers. An increase in growth temperature leads to increased doping efficiency in the case of silicon, whereas the opposite is true in the case of zinc. Deep level transient spectroscopy (DTLS) studies on undoped GaAs layers showed two levels, the expected EL2 level and a carbon-related level. The determination of optimum growth conditions has allowed good quality GaAs and AlGaAs epitaxial layers to be produced for a range of applications.`

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