scholarly journals Transformation kinetics of vapor-deposited thin film organic glasses: the role of stability and molecular packing anisotropy

2015 ◽  
Vol 17 (46) ◽  
pp. 31195-31201 ◽  
Author(s):  
Cristian Rodríguez-Tinoco ◽  
Marta Gonzalez-Silveira ◽  
Joan Ràfols-Ribé ◽  
Aitor F. Lopeandía ◽  
Javier Rodríguez-Viejo
Keyword(s):  
Thin Film ◽  
Thermodynamic Stability ◽  
Growth Front ◽  
Molecular Packing ◽  
Front Velocity ◽  
Transformation Kinetics ◽  
Organic Glasses ◽  
Kinetics Of ◽  
Deposition Conditions

The growth front velocity of indomethacin glasses depends on deposition conditions but is not unambigously determined by its thermodynamic stability when the structure is not completely isotropic.

Role of Surface Reconstruction and External Ion Beam in the Growth Kinetics of III-V Molecular Beam Epitaxy

1987 ◽  
Vol 94 ◽  
Author(s):  
S. B. Ogale ◽  
M. Thomsen ◽  
A. Madhukar
Keyword(s):  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Surface Reconstruction ◽  
Molecular Beam ◽  
Ion Beam ◽  
Growth Front ◽  
Kinetic Rates ◽  
Kinetics Of ◽  
Low Temperature Epitaxy

ABSTRACTComputer simulations of III-V molecular beam epitaxy (MBE) show that surface reconstruction induced modulation of kinetic rates could give rise to ordering in alloys. Results are also presented for the possible influence of an external ion beam in achieving low temperature epitaxy as well as smoother growth front under usual conditions.

scholarly journals Mechanism of Electromigration Failure in Al Thin Film Interconnects Containing Sc

1995 ◽  
Vol 391 ◽  
Author(s):  
Choong-Un Kim ◽  
S. H. Kang ◽  
F.Y. Génin ◽  
J. W. Morris
Keyword(s):  
Thin Film ◽  
Growth Rate ◽  
Grain Growth ◽  
Annealing Time ◽  
Grain Refiner ◽  
Rate Of Evolution ◽  
Failure Statistics ◽  
Al Thin Film ◽  
Kinetics Of

AbstractIn order to understand the role of Sc on electromigration (EM) failure, Al interconnects with 0.1 and 0.3 wt.% Sc were tested as a function of post-pattern annealing time. In response to the evolution of the line structure, the statistics of lifetime evolved. While the addition of Sc greatly reduces the rate of evolution of the failure statistics because the grain growth rate decreases, the MTF variation was found to be very similar to that of pure Al. These observations seem to show that Sc has little influence on the kinetics of Al EM; however, it has some influence on the EM resistance of the line since it is an efficient grain refiner. Unlike Cu in Al, Sc does not seem to migrate, which may explain its lack of influence on the kinetics of Al EM.

RHEED Intensity Oscillation Studies of the Kinetics of GaAs Deposition During Chemical Beam Epitaxy(CBE)

1987 ◽  
Vol 102 ◽  
Author(s):  
A. Robertson ◽  
T.H. Chiu ◽  
W.T. Tsang ◽  
J.E. Cunningham
Keyword(s):  
Growth Rate ◽  
Arrival Rate ◽  
Maximum Growth ◽  
Growth Front ◽  
Propagation Mechanism ◽  
Chemical Beam Epitaxy ◽  
Group V ◽  
Partially Saturated ◽  
Kinetics Of

ABSTRACTRecently we have reported the measurement of RHEED intensity oscillations during Chemical Beam Epitaxy(CBE) of GaAs using triethylgallium(TEG) and As2 derived from an arsine cracker(Appl. Phys. Lett. 50(19), May 11,1987). The existence of RHEED intensity oscillations during CBE growth of GaAs indicates that over the range of conditions studied, growth proceeds via nucleation of islands which grow two-dimensionally as opposed to a vicinal step propagation mechanism. In the same study we observed a significant variation of the GaAs growth rate with substrate temperature at constant flux. In addition, the variation of growth rate with incident flux at constant temperature was found to be non-linear below approximately 500°C and linear above 500'C for incident fluxes yielding maximum growth rates between.2 and 1.8 monolayers/sec. Additional measurements of the dependence of the damping of RHEED intensity oscillations on V/11 ratio have indicated much less sensitivity of the growth front morphology to group V flux in CBE. This behavior is thought to reflect the role of highly mobile, partially saturated ethyl-gallium radicals in epitaxial growth by CBE. Measurements of As2 arrival rate limited intensity oscillations on gallium rich surfaces prepared by pyrolyzing TEG in the absence of As2 have shown that the pyrolysis of TEG is not self-limiting at 500°C and that excess gallium can be deposited on gallium rich surfaces. This paper also describes a simple model of the surface pyrolysis of TEG which is consistent with the above experimental observation.

scholarly journals Structural-phase transformation kinetics during sintering of alumina ceramics using metastable nanopowders

2005 ◽  
Vol 37 (1) ◽  
pp. 35-43 ◽  
Author(s):  
A.S. Kaigorodov ◽  
V.R. Khrustov ◽  
V.V. Ivanov ◽  
A.I. Medvedev ◽  
A.K. Shtol’ts
Keyword(s):  
Diffusion Processes ◽  
Structural Phase ◽  
Alumina Ceramics ◽  
Transformation Kinetics ◽  
Structural Phase Transformation ◽  
Positive Role ◽  
Polymorphous Transition ◽  
Mg Addition ◽  
Kinetics Of

The processes taking place during pressureless sintering of nano- metastable Al2O3, compacted up to high densities (0.7 of the theoretical density) using the magnetic pulsed method were studied. The influence of MgO, TiO2 and ZrO2 additives on the kinetics of Al2O3 polymorphous transition, shrinkage and microstructure evolution during annealing at temperatures up to 1450?C has been studied. We have found that the process of annealing is two-staged starting with a polymorphous transition. Doping changes the starting temperature as well as the shrinkage depth at both stages. TiO2 and ZrO2 additives decrease the temperature of the onset of shrinkage, whereas MgO increases it. The best composition contained MgO in the series of examined types of ceramics with an ?-Al2O3 matrix. The positive role of Mg addition in the production of dense and hard Al2O3 ceramics is related to the nature of Mg influence on the activation of diffusion processes in Al2O3, as well as to the way of uniform distribution of MgO dopant in the material. All these factors provide effective damping of diffusion processes and limit ?-Al2O3 crystal growth. Highly dense MgO, ZrO2 and TiO2 doped Al2O3 ceramics with a grain size of 190, 220, and 250 nm and microhardness of 22, 17 and 17 GPa, correspondingly have been obtained.

Influence of Growth Temperature on the Evolution of Dislocations during PVT Growth of Bulk SiC Single Crystals

2007 ◽  
Vol 556-557 ◽  
pp. 263-266
Author(s):  
Sakwe Aloysius Sakwe ◽  
Peter J. Wellmann
Keyword(s):  
Optical Microscopy ◽  
Single Crystals ◽  
Growth Temperature ◽  
Growth Front ◽  
Growth Surface ◽  
Surface Kinetics ◽  
Step Structure ◽  
Temperature Regimes ◽  
Kinetics Of

In this paper we report, based on analysis of dislocation statistics, on the influence of growth temperature on the nucleation, propagation and annihilation mechanisms of dislocations. Using KOH defect etching and optical microscopy we have conducted dislocation tracking along lengths of crystals grown under various process temperature regimes to study their evolution and propagation mechanisms statistically. We further present the influence of growth temperature on the step structure of the growth front using AFM measurements. From the analysis of dislocation statistics and step structure in relation to temperature we derive the role of surface kinetics of the SiC gas species on the growth surface in dislocation evolution during PVT growth of bulk SiC.

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