A New Experimental Method for Investigating the Nucleation Kinetics of Solids in Supercooled Liquid Si

1995 ◽  
Vol 398 ◽  
Author(s):  
H. Jin Song ◽  
James S. Im
Keyword(s):  
Thin Film ◽  
Experimental Method ◽  
Supercooled Liquid ◽  
Isothermal Transformation ◽  
Frequency Range ◽  
Nucleation Kinetics ◽  
Detection Techniques ◽  
Wide Range ◽  
Solid Nucleation ◽  
Kinetics Of

ABSTRACTIn this paper, we first describe and then demonstrate the soundness of a new experimental method that is designed to deliver a wide range of accurately measured nucleation rates of solids in supercooled liquid Si. The method utilizes thin-film processes, as well as laser-quenching and detection techniques, in order to first induce isothermal transformation and then extract the corresponding solid nucleation rates over a frequency range potentially greater than ten orders of magnitude. The technological and scientific gains that can result from acquiring such information are discussed.

Transient and Athermal Nucleation of Solids in Rapidly Quenched Liquid Si

1995 ◽  
Vol 398 ◽  
Author(s):  
Vikas V. Gupta ◽  
James S. Im
Keyword(s):  
Supercooled Liquid ◽  
Nucleation Theory ◽  
Classical Nucleation Theory ◽  
Equilibrium Conditions ◽  
Common Notion ◽  
Athermal Nucleation ◽  
The Common ◽  
Transient Nucleation ◽  
Solid Nucleation ◽  
Kinetics Of

ABSTRACTWe have theoretically investigated the nature and kinetics of solid nucleation in supercooled liquid Si within the framework of the classical nucleation theory, and corresponding to the cases in which the liquids are quenched at extremely high quenching rates (from 109 to 1011 K/s). In doing so, we identify and draw a general conclusion that in addition to the well-treated phenomenon of transient nucleation, one must also consider the mechanism of athermal nucleation in order to properly elucidate the situations that are encountered at such high quenching rates. Moreover, contrary to the common notion that the transient effect is relevant at low temperatures where sluggish kinetics prevail, it is noted that the effect can also become prominent at near-equilibrium conditions due to the increase in the time needed by the embryos to reach the exceedingly large critical size.

Nucleation kinetics of cadmium sulphide thin film — CVD technique

2000 ◽  
Vol 63 (2) ◽  
pp. 163-166 ◽  
Author(s):  
S. Chenthamarai ◽  
D. Jayaraman ◽  
C. Subramanian
Keyword(s):  
Thin Film ◽  
Cadmium Sulphide ◽  
Nucleation Kinetics ◽  
Kinetics Of

Impact of Hydrogen Dilution on the Properties and Light Induced Changes of A-SI:H Based Materials and Solar Cells

1997 ◽  
Vol 467 ◽  
Author(s):  
Yeeheng Lee ◽  
Lihong Jiao ◽  
Joohyun Koh ◽  
Hiroyuki Fujiwara ◽  
Zhou Lu ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Substrate Temperature ◽  
Growth Kinetics ◽  
Degradation Kinetics ◽  
Hydrogen Dilution ◽  
Si Solar Cells ◽  
Wide Range ◽  
Induced Changes ◽  
Kinetics Of

ABSTRACTStudies have been carried out on a-Si:H materials and corresponding solar cells fabricated with and without hydrogen dilution of silane by rf PECVD. The effect of hydrogen dilution on the growth kinetics and microstructures and their dependence on the substrate temperature have been studied. Hydrogen diluted a-Si:H materials and solar cells exhibit improved properties and higher stability to light induced changes. Distinct differences are found in the electron mobility lifetime (μτ) products and subgap absorption over a wide range of generation rates. Striking differences are also found in the kinetics of light induced degradation in both the materials and their corresponding solar cells. Direct correlations are presented between the degradation kinetics of p(a-SiC:H)/i(a-Si:H)/n(μc-Si) solar cells and those of thin film materials constituting the i-layers.

Modelling Solid Nucleation and Growth In Supercooled Liquid

1999 ◽  
Vol 580 ◽  
Author(s):  
J.P. Leonard ◽  
James S. Im
Keyword(s):  
Random Number ◽  
Thermal Evolution ◽  
Supercooled Liquid ◽  
Nucleation And Growth ◽  
Nucleation Kinetics ◽  
Time Step ◽  
Si Films ◽  
Solid Nucleation ◽  
Random Nature ◽  
Induced Crystallization

AbstractIn this paper, we present a numerical model that incorporates algorithms to simulate nucleation and growth in supercooled liquid in a manner that properly accounts for the stochastic nature of nucleation. The basis of our model relies on a discretization of space and time to address thermal evolution, rapid growth of the undercooled interface, and nucleation in supercooled liquid. The present formulation of nucleation permits the spatially and temporally random nature of the phenomenon to be manifested in the transformation and resultant microstructure. This is accomplished by (1) calculating the probability of nucleation in each and every liquid node during each time step using the Poisson expression, and (2) triggering nucleation if and only when the random number assigned to a node for the time step is less than the calculated nucleation probability. No empirical or deterministic conditions for nucleation are imposed; nucleation occurs spontaneously and solely based on nucleation kinetics. We demonstrate the effectiveness of the overall model by analyzing conditions similar to those encountered in pulsed laser-induced crystallization of thin Si films, and discuss the generality of the proposed stochastic formulation of nucleation.

Growth kinetics of Al2Cu in an Al-1.5Cu thin film by in Situ TEM

1993 ◽  
Vol 51 ◽  
pp. 1172-1173
Author(s):  
M. Park ◽  
S.J. Krause ◽  
S.R. Wilson
Keyword(s):  
Thin Film ◽  
In Situ Tem ◽  
Collector Plate ◽  
Transmission Electron ◽  
Device Processing ◽  
Corrosion Susceptibility ◽  
Precipitation Phenomena ◽  
Semiconductor Chips ◽  
Kinetics Of

Cu alloying in Al interconnection lines on semiconductor chips improves their resistance to electromigration and hillock growth. Excess Cu in Al can result in the formation of Cu-rich Al2Cu (θ) precipitates. These precipitates can significantly increase corrosion susceptibility due to the galvanic action between the θ-phase and the adjacent Cu-depleted matrix. The size and distribution of the θ-phase are also closely related to the film susceptibility to electromigration voiding. Thus, an important issue is the precipitation phenomena which occur during thermal device processing steps. In bulk alloys, it was found that the θ precipitates can grow via the grain boundary “collector plate mechanism” at rates far greater than allowed by volume diffusion. In a thin film, however, one might expect that the growth rate of a θ precipitate might be altered by interfacial diffusion. In this work, we report on the growth (lengthening) kinetics of the θ-phase in Al-Cu thin films as examined by in-situ isothermal aging in transmission electron microscopy (TEM).

Scintigraphic studies in rats. Kinetics of insulin analogues covering wide range of receptor affinities

Diabetes ◽  
1991 ◽  
Vol 40 (5) ◽  
pp. 628-632 ◽  
Author(s):  
I. Jensen ◽  
V. Kruse ◽  
U. D. Larsen
Keyword(s):  
Insulin Analogues ◽  
Wide Range ◽  
Kinetics Of

Reordering and Crystallization of Silicon Carbide Amorphized by Neutron Irradiation

2000 ◽  
Vol 650 ◽  
Author(s):  
Lance L. Snead ◽  
Martin Balden
Keyword(s):  
Thin Film ◽  
Silicon Carbide ◽  
Crystallization Kinetics ◽  
Neutron Irradiation ◽  
Onset Temperature ◽  
Kinetics Of Crystallization ◽  
Crystallization Onset Temperature ◽  
Crystallization Onset ◽  
Kinetics Of

ABSTRACTDensification and crystallization kinetics of bulk SiC amorphized by neutron irradiation is studied. The temperature of crystallization onset of this highly pure, fully amorphous bulk SiC was found to be between 875-885°C and crystallization is nearly complete by 950°C. In-situ TEM imaging confirms the onset of crystallization, though thin-film effects apparently alter the kinetics of crystallization above this temperature. It requires >1125°C for complete crystallization of the TEM foil. Annealing at temperatures between the irradiation and crystallization onset temperature is seen to cause significant densification attributed to a relaxation, or reordering, of the as-amorphized structure.

Wide range modulation of synaptic weight in thin-film transistors with hafnium oxide gate insulator and indium-zinc oxide channel layer for artificial synapse application

Nanoscale ◽  
2021 ◽  
Author(s):  
Keonwon Beom ◽  
Jimin Han ◽  
Hyun-Mi Kim ◽  
Tae-Sik Yoon
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Thin Film Transistors ◽  
Hafnium Oxide ◽  
Synaptic Weight ◽  
Drain Current ◽  
Gate Insulator ◽  
Channel Layer ◽  
Indium Zinc Oxide ◽  
Wide Range

Wide range synaptic weight modulation with a tunable drain current was demonstrated in thin-film transistors (TFTs) with a hafnium oxide (HfO2−x) gate insulator and an indium-zinc oxide (IZO) channel layer...

Quantitative Study of Al/W Interaction In Si/SiO2/W-Ti/Al Thin Film System

1988 ◽  
Vol 119 ◽  
Author(s):  
Hung-Yu Liu ◽  
Peng-Heng Chang ◽  
Jim Bohlman ◽  
Hun-Lian Tsai
Keyword(s):  
Thin Film ◽  
Film System ◽  
X Ray Diffraction ◽  
Compound Formation ◽  
X Ray ◽  
Thin Film System ◽  
Glancing Angle ◽  
Integrated Intensity ◽  
Al Thin Film ◽  
Kinetics Of

AbstractThe interaction of Al and W in the Si/SiO2/W-Ti/Al thin film system is studied quantitatively by glancing angle x-ray diffraction. The formation of Al-W compounds due to annealing is monitored by the variation of the integrated intensity from a few x-ray diffraction peaks of the corresponding compounds. The annealing was conducted at 400°C, 450°C and 500°C from 1 hour to 300 hours. The kinetics of compound formation is determined using x-ray diffraction data and verified by TEM observations. We will also show the correlation of the compound formation to the change of the electrical properties of these films.

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