Liquid-Solid Interface Morphologies and Defect Structures in Zone-Melting-Recrystallized Silicon-On-Insulator Films

1987 ◽  
Vol 107 ◽  
Author(s):  
J. S. Im ◽  
C. K. Chen ◽  
C. V. Thompson ◽  
M. W. Geis ◽  
H. Tomita
Keyword(s):  
Zone Melting ◽  
Silicon On Insulator ◽  
Radiative Heating ◽  
Interfacial Region ◽  
Defect Structures ◽  
Interface Morphology ◽  
Experimental Conditions ◽  
Solid Interface ◽  
Free Films

AbstractIn-situ optical microscopy has been used to observe liquid-solid interface morphologies during zone-melting recrystallization of silicon-on-insulator films. These morphologies have been correlated with the defect morphologies of the recrystallized films. Stable cellular solidification fronts, which are obtained at low zone velocities if the radiation intensity gradient in the interfacial region is small, yield subboundary free films. We suggest that under these experimental conditions the interface morphology is primarily the result of radiative heating rather than constitutional supercooling.

Growth -Front Modulation in Lamp Zone Melting of Si on SiO2

1986 ◽  
Vol 74 ◽  
Author(s):  
D. Dutartre ◽  
D. Bensahel ◽  
M. Haond
Keyword(s):  
Solidification Front ◽  
Growth Front ◽  
Zone Melting ◽  
Silicon On Insulator ◽  
Polysilicon Film ◽  
Defect Localization ◽  
In Situ Observations ◽  
Periodical Variation

AbstractWe present 3 techniques of defect localization we have studied in order to produce Silicon On Insulator films obtained by Lamp Zone Melting. They consist in a periodical variation of the thickness of either the oxide cap, or the polysilicon film, or the underlying oxide layer. We compare the crystallographic quality of the resulting films and in-situ observations of the solidification front for each structure.

Melting and Solidification Dynamics in Zone Melting of Si Films.

1987 ◽  
Vol 107 ◽  
Author(s):  
D. Dutartre
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Zone Melting ◽  
Silicon On Insulator ◽  
Experimental Conditions ◽  
Melting Front ◽  
Physical Mechanisms ◽  
Si Films ◽  
Melting And Solidification

AbstractWe discuss the physics involved in the melting and solidification of Silicon On Insulator thin films (SOI) using lamp or graphite strip heaters. The melting front, called “explosive melting”, controls to a large part the final morphological quality of the SOI film. It exhibits instabilities which can (i) nucleate the dewetting of the film, (ii) cause voids, and (iii) produce a poor surface morphology. The morphologies of the solidification fronts are analyzed. We show that, depending on the experimental conditions, different physical mechanisms are responsible for the front breakdown. Thus we propose that the variety of front morphologies results from the variety of the mechanisms involved, and of their combinations with the “faceting effects”.

Thermal Profiles in Silicon-On-Insulator (Sod Material Recrystallized With Scanning Light Line Sources

1984 ◽  
Vol 35 ◽  
Author(s):  
Katsuhiko Kubota ◽  
Charles E. Hunt ◽  
Jeffrey Frey
Keyword(s):  
Zone Melting ◽  
Silicon On Insulator ◽  
Source Zone ◽  
Two Dimensional ◽  
Phase Boundaries ◽  
Multilayered Structures ◽  
Experimental Conditions ◽  
Dimensional Solution ◽  
Solidification Model ◽  
Light Line

ABSTRACTA two dimensional solution of the classical heat equation is obtained and used to predict thermal profiles during line source zone melting recrystallization of silicon on insulators. A macroscopic solidification model is used to find the extent of the molten zone in multilayered structures. The problems of convergence associated with moving phase boundaries are reduced by using transformed temperature and the enthalpy model The resultant isotherms, obtained at varying zone scan speeds, indicate optimum experimental conditions.

Solidification Interface Morphologies in Zone Melting Recrystallization

1986 ◽  
Vol 74 ◽  
Author(s):  
J. S. Im ◽  
C. V. Thompson ◽  
H. Tomita
Keyword(s):  
Optical Microscopy ◽  
Radiation Intensity ◽  
Zone Melting ◽  
Spatial Gradient ◽  
Solid Interface ◽  
Solidification Interface ◽  
Moving Liquid

AbstractUsing in situ optical microscopy we have studied the morphology of the liquid-solid interface during zone melting recrystallization. We have observed a variety of interface morphologies, each of which corresponds to specific types and distributions of subboundaries in the solidified material. We have also observed a variety of morphologies for stationary interfaces. We propose that perturbations in both the stationary and moving liquid-solid interfaces develop, at least in part, due to the spatial gradient in the radiation intensity in the region of the interface.

Microscopy of Thin Si Films During Lamp Zone Melting

1985 ◽  
Vol 53 ◽  
Author(s):  
D. Dutartre ◽  
M. Haond ◽  
D. Bensahel
Keyword(s):  
Zone Melting ◽  
Silicon On Insulator ◽  
Spatial Modulation ◽  
Freezing Front ◽  
Melting Front ◽  
Scan Speed ◽  
Entrainment Effect ◽  
Si Films ◽  
Melting And Solidification

ABSTRACTThe melting and solidification fronts of thin Silicon On Insulator (SOI) films have been observed in-situ. The melting front does not advance continuously but by bursts. This so called “explosive melting” allows to explain the appearance of defects (such as voids and surface roughness) observed in the recrystallized film. The freezing front is observed in the case where a pattern for the entrainment of the defects has been etched in the underlying oxide: we show that the entrainment effect is due to the spatial modulation of the solidification front by the structure. Furthermore, the scan speed influences the morphology of the liquid/solid interface and the defect entrainment efficiency.

scholarly journals On realistic size equivalence and shape of spheroidal Saharan mineral dust particles applied in solar and thermal radiative transfer calculations

2011 ◽  
Vol 11 (9) ◽  
pp. 4469-4490 ◽  
Author(s):  
S. Otto ◽  
T. Trautmann ◽  
M. Wendisch
Keyword(s):  
Land Surface ◽  
Mineral Dust ◽  
Single Scattering ◽  
Radiative Heating ◽  
Dust Particles ◽  
Axis Ratio ◽  
Solar Cooling ◽  
Prolate Shape ◽  
Spheroidal Model

Abstract. Realistic size equivalence and shape of Saharan mineral dust particles are derived from in-situ particle, lidar and sun photometer measurements during SAMUM-1 in Morocco (19 May 2006), dealing with measured size- and altitude-resolved axis ratio distributions of assumed spheroidal model particles. The data were applied in optical property, radiative effect, forcing and heating effect simulations to quantify the realistic impact of particle non-sphericity. It turned out that volume-to-surface equivalent spheroids with prolate shape are most realistic: particle non-sphericity only slightly affects single scattering albedo and asymmetry parameter but may enhance extinction coefficient by up to 10 %. At the bottom of the atmosphere (BOA) the Saharan mineral dust always leads to a loss of solar radiation, while the sign of the forcing at the top of the atmosphere (TOA) depends on surface albedo: solar cooling/warming over a mean ocean/land surface. In the thermal spectral range the dust inhibits the emission of radiation to space and warms the BOA. The most realistic case of particle non-sphericity causes changes of total (solar plus thermal) forcing by 55/5 % at the TOA over ocean/land and 15 % at the BOA over both land and ocean and enhances total radiative heating within the dust plume by up to 20 %. Large dust particles significantly contribute to all the radiative effects reported. They strongly enhance the absorbing properties and forward scattering in the solar and increase predominantly, e.g., the total TOA forcing of the dust over land.

In situ monitoring of isophorone diisocyanate-based flexible polyurethane foams formation

2016 ◽  
Vol 54 (1) ◽  
pp. 37-52 ◽  
Author(s):  
I Eceiza ◽  
L Irusta ◽  
A Barrio ◽  
MJ Fernández-Berridi
Keyword(s):  
Foam Height ◽  
Polyurethane Foams ◽  
In Situ Monitoring ◽  
Generation Process ◽  
Isophorone Diisocyanate ◽  
Experimental Conditions ◽  
Foaming Process ◽  
Foam Generation ◽  
Flexible Polyurethane

Novel isophorone diisocyanate-based flexible polyurethane foams were prepared by the one-step method in a computerized foam qualification system (FOAMAT). The experimental conditions to obtain this type of foams, in relation to the nature and concentration of catalysts as well as the reaction temperature, were established as no data were available in scientific literature. The chemical reactions occurring during the foam generation process were monitored in situ by attenuated total reflectance-FTIR spectroscopy. The kinetics of the foam generation was fitted to an nth order model and the data showed that the foaming process adjusted to a first-order kinetics. The physical changes as pressure, foam height, and dielectric polarization were monitored by the FOAM software (FOAMAT). According to these parameters, the foaming process was divided into four steps: bubble growth, bubble packing, cell opening, and final curing.

In situ synthesis of composite MTiO3–Al2O3 coatings via laser zone melting

2007 ◽  
Vol 9 (5) ◽  
pp. 404-409 ◽  
Author(s):  
V.V. Lennikov ◽  
J.M. Pedra ◽  
J.J. Gómez ◽  
G.F. de la Fuente ◽  
J.B. Carda
Keyword(s):  
Zone Melting ◽  
In Situ Synthesis
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