Nucleation and Heterointerface Structure of InAs Epilayers Grown on InP Substrates

1992 ◽  
Vol 280 ◽  
Author(s):  
K. S. Chandra Sekhar ◽  
A. K. Ballal ◽  
L. Salamanca-Riba ◽  
D. L. Partin
Keyword(s):  
Surface Morphology ◽  
Electronic Properties ◽  
Growth Temperature ◽  
High Speed ◽  
Interface Roughness ◽  
Structural Defects ◽  
Lower Growth ◽  
Substrate Interface ◽  
Film Substrate ◽  
Inp Substrates

ABSTRACTHeteroepitaxial growth of indium arsenide films on indium phosphide substrates is being actively pursued since the electronic properties of these films make them promising materials for optoelectronic and other high speed devices. The various structural aspects of the film that affect their electronic properties are structural defects like dislocations, film-substrate interface roughness and chemical inhomogeneities. In InAs films, electrons accumulate at the film-air interface, making surface morphology an important factor that decides the electronic properties. The InAs films used in this study were grown on InP substrates by metal organic vapor deposition, at different temperatures. A higher growth temperature not only resulted in poor surface morphology of the film, but also created a rough film-substrate interface. However, at all deposition temperatures, the film-substrate interfaces are sharp. At lower growth temperature, the interfaces were flat. Films grown at lower temperatures had good surface morphology and a flat and shaip heterointerface.

LPE Growth of Textured KNbO3 Film Using SrTiO3 Substrate and V2O5 Flux

2006 ◽  
Vol 11-12 ◽  
pp. 109-112
Author(s):  
T. Hibino ◽  
Kenichi Kakimoto ◽  
Hitoshi Ohsato
Keyword(s):  
Thin Films ◽  
Phase Diagram ◽  
Growth Rate ◽  
Liquid Phase ◽  
Surface Morphology ◽  
Liquid Phase Epitaxy ◽  
Growth Temperature ◽  
Film Growth ◽  
Lower Growth ◽  
Lower Growth Temperature

KNbO3 thin films were grown on (100) and (110) SrTiO3 substrates by liquid phase epitaxy (LPE) technique. The film orientation and surface morphology were characterized by XRD and AFM, respectively. The limited phase diagram of K2O-Nb2O5-V2O5 system was prepared by DTA measurement to investigate the effect of V2O5 flux on the LPE growth of KNbO3 film. The use of V2O5 flux enhanced a film growth rate at lower growth temperature.

Epitaxial Films of Faas and Fan on Fianit Substrates

1998 ◽  
Vol 512 ◽  
Author(s):  
A. N. Buzynin ◽  
V. V. Osiko ◽  
E. E. Lomonova ◽  
Yu. N. Buzynin ◽  
A. S. Usikov
Keyword(s):  
Surface Morphology ◽  
Epitaxial Films ◽  
Structural Perfection ◽  
Substrate Interface ◽  
Preliminary Annealing ◽  
Oxygen Conditions ◽  
High Structural Perfection ◽  
Film Substrate ◽  
Made In ◽  
Crystalline Growth

ABSTRACTSubrmicron heteroepitaxial GaAs and GaN films were grown by both conventional MOCVD and «capillary epitaxy» technique on (001) and (111) fianit (YSZ)substrates. A preliminary annealing of the substrates under vakuum was made in order to stabilize the surface by removing of some amount of oxygen. Conditions of single crystalline growth of GaAs submicron films (50–500nm) have been determined. The films had mirror-like surface morphology and high structural perfection. The distribution of Zr, O, Y across the film-substrate interface was sharp and doping impurities contents were uniform over the film. PL spectra of undoped GaN films on YSZ were studied.

Defect Structures in Epitaxially Grown InAs Films on InP Substrates

1991 ◽  
Vol 238 ◽  
Author(s):  
A. K. Ballal ◽  
L. Salamanca-Riba ◽  
D. L. Partin ◽  
J. Heremans ◽  
L. Green ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Organic Chemical ◽  
Misfit Dislocations ◽  
Defect Structures ◽  
Substrate Interface ◽  
Film Substrate ◽  
Inp Substrates

ABSTRACTIn this paper we study the lattice-mismatch induced defect structures of InAs films grown on semi-insulating InP substrates using metal organic chemical vapor deposition. The defect structure studies were carried out on films of equal total thicknesses but for different duration for nucleation of a layer of InAs deposited at low temperature on the substrate. Misfit strain is caused by the inherent lattice mismatch of approximately three percent and this is partially relieved by the generation of misfit dislocations at the film/substrate interface. Transmission electron microscopy studies show the presence of an intrinsic strain and the generation of thermal etchpits at the heteroepitaxial interface. Our studies show that there is a direct correlation between the density of dislocations generated at the film/substrate interface and the duration of nucleation of the film on the substrate. Dislocation densities at the surface of the InAs films and at the heteroepitaxial interface differed by almost two orders of magnitude. High resolution electron microscopy reveals abrupt and sharp interfaces in films with thick nucleation layers and also confirms that the lattice mismatch is partially accommodated by the generation of misfit dislocations at the film/substrate interface.

Correlation of growth temperature with stress, defect states and electronic structure in an epitaxial GaN film grown on c-sapphire via plasma MBE

2016 ◽  
Vol 18 (11) ◽  
pp. 8005-8014 ◽  
Author(s):  
Shibin Krishna ◽  
Neha Aggarwal ◽  
Monu Mishra ◽  
K. K. Maurya ◽  
Sandeep Singh ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Surface Morphology ◽  
Electronic Properties ◽  
Significant Influence ◽  
Growth Temperature ◽  
Defect States ◽  
Stress Engineering ◽  
Gan Film

Stress engineering is shown to have a significant influence on the defect states, surface morphology and electronic properties of a GaN film grown on c-sapphire.

Effects of Growth Temperature on MOCVD-Grown GaAs-ON-Si

1989 ◽  
Vol 148 ◽  
Author(s):  
S. Nozaki ◽  
N. Noto ◽  
M. Okada ◽  
T. Egawa ◽  
T. Soga ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Growth Temperature ◽  
Lower Growth ◽  
Rocking Curve ◽  
X Ray ◽  
Gaas On Si ◽  
Good Surface ◽  
Step Growth ◽  
Higher Temperature ◽  
Lower Growth Temperature

ABSTRACTEffects of growth temperature on crystallinity and surface morphology of MOCVD-grown GaAs-on-Si were studied. The FWHM of the (400) x-ray peak in the rocking curve of GaAs-on-Si reduces from 340 to 230 arcs with increasing growth temperature from 650 to 700°C, but further increase of growth temperature does not significantly decrease the FWHM. The surface morphology of GaAs-on-Si grown at higher temperature is scaly and rough. Lower growth temperature is desirable to obtain GaAs-on-Si with good surface morphology. In order to eliminate the trade-off between crystallinity and surface morphology, the three-step growth process is proposed.

Parallel Glide: A Fundamentally Different Type of Dislocation Motion in Ultrathin Metal Films

2003 ◽  
Vol 779 ◽  
Author(s):  
T. John Balk ◽  
Gerhard Dehm ◽  
Eduard Arzt
Keyword(s):  
Thermal Cycling ◽  
Grain Boundaries ◽  
Film Surface ◽  
Metal Films ◽  
Geometric Constraints ◽  
Film Stress ◽  
Diffusional Creep ◽  
Creep Model ◽  
Substrate Interface ◽  
Film Substrate

AbstractWhen confronted by severe geometric constraints, dislocations may respond in unforeseen ways. One example of such unexpected behavior is parallel glide in unpassivated, ultrathin (200 nm and thinner) metal films. This involves the glide of dislocations parallel to and very near the film/substrate interface, following their emission from grain boundaries. In situ transmission electron microscopy reveals that this mechanism dominates the thermomechanical behavior of ultrathin, unpassivated copper films. However, according to Schmid's law, the biaxial film stress that evolves during thermal cycling does not generate a resolved shear stress parallel to the film/substrate interface and therefore should not drive such motion. Instead, it is proposed that the observed dislocations are generated as a result of atomic diffusion into the grain boundaries. This provides experimental support for the constrained diffusional creep model of Gao et al.[1], in which they described the diffusional exchange of atoms between the unpassivated film surface and grain boundaries at high temperatures, a process that can locally relax the film stress near those boundaries. In the grains where it is observed, parallel glide can account for the plastic strain generated within a film during thermal cycling. One feature of this mechanism at the nanoscale is that, as grain size decreases, eventually a single dislocation suffices to mediate plasticity in an entire grain during thermal cycling. Parallel glide is a new example of the interactions between dislocations and the surface/interface, which are likely to increase in importance during the persistent miniaturization of thin film geometries.

scholarly journals Surface Forming Criteria of Ti-6AL-4V Titanium Alloy under Laser Loading

2021 ◽  
Vol 11 (12) ◽  
pp. 5406
Author(s):  
Fei Yin ◽  
Xia Ye ◽  
Hongbing Yao ◽  
Pengyu Wei ◽  
Xumei Wang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Surface Morphology ◽  
High Speed ◽  
Yttrium Aluminum Garnet ◽  
Laser Energy ◽  
Target Material ◽  
Nanosecond Laser ◽  
Laser Shock ◽  
Shock Condition ◽  
Key Factor

In order to study the spallation phenomenon of titanium alloy under the shock of nanosecond laser, the Neodymium-Yttrium-Aluminum Garnet laser was used to carry out laser shock experiments on the surface of titanium alloy. By observing and measuring the surface morphology of the target material, the forming factors and the changes of the surface morphology under different parameter settings, the forming criteria of the titanium alloy were obtained. The results show that under the single variable method, the change of laser energy can affect the target shape variable, and there is a positive correlation between them. When the thickness was greater than or equal to 0.08 mm, no obvious cracks were found in the targets. Moreover, the number of impact times was the key factor for the target deformation; with the growth of impact times, the target deformation gradually became larger until the crack appeared. The larger the diameter of the spot, the more likely the target was to undergo plastic deformation. The surface of titanium alloy with a thickness of 0.08 mm appeared to rebound under specific laser shock condition. The changes in the back of the target material were observed in real time through a high-speed camera, and the plasma induced by the laser was observed in the process. This study is based on the results of previous studies to obtain the titanium alloy forming criteria, which provides a basis for the setting of laser parameters and the thickness of the target when the nanosecond laser impacts the Ti-6AL-4V target.

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