Crystallization Kinetics of Fe-DOPED A1203

1994 ◽  
Vol 357 ◽  
Author(s):  
Todd W. Simpson ◽  
Ian V. Mitchell ◽  
Ning Yu ◽  
Michael Nastasi ◽  
Paul C. Mcintyre
Keyword(s):  
Crystallization Kinetics ◽  
Annealing Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Time Resolved ◽  
Α Phase ◽  
Kinetics Of ◽  
Beam Deposition

AbstractTime resolved optical reflectivity (TRR) and Rutherford backscattering spectrometry (RBS) and ion channelling methods have been applied to determine the crystallization kinetics of Fe-doped A1203 in the temperature range of 900-1050°C. Amorphous A1203 films, approximately 250 nm thick and with Fe cation concentrations of 0, 1.85, 2.2 and 4.5%, were formed by e-beam deposition on single crystal, [0001] oriented, A1203 substrates. Annealing was performed under an oxygen ambient in a conventional tube furnace, and the optical changes which accompany crystallization were monitored, in situ, by TRR with a 633nm wavelength laser.Crystallization is observed to proceed via solid phase epitaxy. An intermediate, epitaxial phase of -γ-Al203 is formed before the samples reach the ultimate annealing temperature. The 5% Fe-doped film transforms from γ to α-A1203 at a rate approximately 10 times that of the pure A1203 film and the 1.85% and 2.2% Fe-doped films transform at rates between these two extremes. The Fe-dopants occupy substitional lattice sites in the epilayer. Each of the four sets of specimens displays an activation energy in the range 5.0±0.2eV for the γ,α phase transition.

Kinetics of Intrinsic and Dopant-Enhanced Solid Phase Epitaxy in Buried Amorphous Si Layers

1996 ◽  
Vol 439 ◽  
Author(s):  
J. C. McCallum
Keyword(s):  
Ion Implantation ◽  
Dopant Concentration ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Entire Concentration Range ◽  
Time Resolved ◽  
Amorphous Si ◽  
First Time ◽  
Kinetics Of ◽  
Suitable Environment

AbstractThe kinetics of intrinsic and dopant-enhanced solid phase epitaxy (SPE) have been measured in buried amorphous Si (a-Si) layers produced by ion implantation. Buried a-Si layers formed by self-ion implantation provide a suitable environment for studies of the intrinsic growth kinetics of amorphous Si, free from the rate-retarding effects of H. For the first time, dopant-enhanced SPE rates have been measured under these H-free conditions. Buried a-Si layers containing uniform As concentration profiles ranging from 1–16.1 × 1019 As.cm−3 were produced by multiple-energy ion implantation and time resolved reflectivity was used to measure SPE rates over the temperature range 480–660°C. In contrast to earlier studies, the dopant-enhanced SPE rate is found to depend linearly on the As concentration over the entire concentration range measured. The SPE rate can be expressed in the form, v/vi(T) = 1 + N/[No exp(-ΔE/kT)], where vi(T) is the intrinsic SPE rate, N is the dopant concentration and No = 1.2 × 1021 cm−3, ΔE = 0.21 eV.

Synthesis of Dislocation Free Siy(SnxC1−x)1−y Alloys by Molecular Beam Deposition and Solid Phase Epitaxy

1993 ◽  
Vol 298 ◽  
Author(s):  
Gang He ◽  
Mark D. Savellano ◽  
Harry A. Atwater
Keyword(s):  
Molecular Beam ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
Pure Silicon ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Molecular Beam Deposition ◽  
Beam Deposition

AbstractSynthesis of strain-compensated single-crystal Siy(SnxC1-x)1-y alloy films on silicon (100) substrates has been achieved with compositions of tin and carbon greatly exceeding their normal equilibrium solubility in silicon. Amorphous SiSnC alloys were deposited by molecular beam deposition from solid sources followed by thermal annealing. In situ monitoring of crystallization was done using time-resolved reflectivity. Good solid phase epitaxy was observed for Si0.98Sn0.01C0.01, at a rate about 20 times slower than that of pure silicon. Compositional and structural analysis was done using Rutherford backscattering, electron microprobe, ion channeling, x-ray diffraction, and transmission electron microscopy.

Interface Velocity and Noble Metal Segregation During Ion Beam Induced Epitaxial Crystallization

1989 ◽  
Vol 157 ◽  
Author(s):  
J. S. Custer ◽  
Michael O. Thompson ◽  
D. C. Jacobson ◽  
J. M. Poate
Keyword(s):  
Solid Phase ◽  
Ion Beam ◽  
Interface Velocity ◽  
Solid Phase Epitaxy ◽  
Segregation Coefficient ◽  
Time Resolved ◽  
Interfacial Segregation ◽  
Amorphous Si ◽  
Impurity Profiles

ABSTRACTThe interface velocity of Au and Ag doped amorphous Si during ion beam induced epitaxy was measured using in situ time resolved reflectivity. Interfacial segregation coefficients were determined as a function of composition from numerical simulations. At 320°C Au impurities enhanced the velocity by up to a factor of 2.5 compared to the intrinsic case. Silver slightly retarded re-growth by 10 %. These effects are qualitatively similar to the case of thermal solid phase epitaxy. Using the measured impurity profiles and interface velocity, computer simulations relate the segregation coefficient to the concentrations of the impurity at the interface. In both cases, the segregation coefficient increases with increasing interfacial impurity concentration.

In situ TEM studies of the effect of misfit strain on the kinetics of sil-xgex solid phase epitaxy: temperature calibration & surface effects

1992 ◽  
Vol 50 (2) ◽  
pp. 1344-1345
Author(s):  
David C. Paine ◽  
David J. Howard ◽  
N.D. Evans
Keyword(s):  
Solid Phase ◽  
Misfit Strain ◽  
Alloy Layer ◽  
In Situ Tem ◽  
Transformation Rate ◽  
Solid Phase Epitaxy ◽  
Si Substrates ◽  
Kinetics Of ◽  
Annealing Experiments

While in situ TEM studies have proven useful for the direct observation of solid-state reaction mechanisms, such studies rarely provide quantitative kinetic data. This limitation is due to problems associated with the accurate measurement of local sample temperature, assessment of beam heating and damage, and minimization of thin-film effects. Sinclair et al. have proposed a technique for establishing the temperature of a sample during in situ TEM annealing experiments in which the wellcharacterized Si <001> solid phase epitaxy amorphous-crystalline (a/c) transformation rate is used to estimate the temperature in an adjacent (but not contiguous) region of the specimen. We have used this in situ technique to determine the activation energy for strained solid phase epitaxy of Sil-xGex (x=5.4, 11.6, and 17 at.%). The alloys were grown by CVD on <001> Si substrates to a thickness of approximately 200 nm. The entire alloy layer, and 180 nm of the underlying substrate, were amorphized with 100, followed by 200 keV 29Si implantation.

Kinetics of Intrinsic and Dopant-Enhanced Solid Phase Epitaxy in Buried Amorphous Si Layers

1996 ◽  
Vol 438 ◽  
Author(s):  
J. C. McCallum
Keyword(s):  
Ion Implantation ◽  
Dopant Concentration ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Entire Concentration Range ◽  
Time Resolved ◽  
Amorphous Si ◽  
First Time ◽  
Kinetics Of ◽  
Suitable Environment

AbstractThe kinetics of intrinsic and dopant-enhanced solid phase epitaxy (SPE) have been measured in buried amorphous Si (a-Si) layers produced by ion implantation. Buried a-Si layers formed by self-ion implantation provide a suitable environment for studies of the intrinsic growth kinetics of amorphous Si, free from the rate-retarding effects of H. For the first time, dopant-enhanced SPE rates have been measured under these H-free conditions. Buried a- Si layers containing uniform As concentration profiles ranging from 1–16.1 × 1019 As.cm-3 were produced by multiple-energy ion implantation and time resolved reflectivi[ty was used to measure SPE rates over the temperature range 480–660°C. In contrast to earlier studies, the dopant-enhanced SPE rate is found to depend linearly on the As concentration over the entire concentration range measured. The SPE rate can be expressed in the form, v/vi(T) = 1 + N/[No exp(−Λ E/kT)], where vi(T) is the intrinsic SPE rate, N is the dopant concentration and No = 1.2 × 1021 cm-3, ΔE = 0.21 eV.

Intrinsic and Dopant-Enhanced Solid Phase Epitaxy in Amorphous Germanium

2008 ◽  
Vol 1070 ◽  
Author(s):  
Brett Cameron Johnson ◽  
Paul Gortmaker ◽  
Jeffrey C. McCallum
Keyword(s):  
Activation Energy ◽  
Ion Implantation ◽  
Fermi Level ◽  
Concentration Profile ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Amorphous Germanium ◽  
Time Resolved ◽  
Temperature Range ◽  
Kinetics Of

ABSTRACTThe kinetics of intrinsic and dopant-enhanced solid phase epitaxy (SPE) are studied in thick amorphous germanium (a-Ge) layers formed by ion implantation on <100> Ge substrates. The SPE rates for H-free Ge were measured with a time-resolved reflectivity (TRR) system in the temperature range 300 – 540 °C and found to have an activation energy of (2.15 ± 0.04) eV. Dopant enhanced SPE was measured in a-Ge layers containing a uniform concentration profile of implanted As spanning the concentration regime 1 – 10 × 1019 cm3. The generalized Fermi level shifting model shows excellent fits to the data.

Kinetics and Microstructure of Transiently Annealed Implanted Polycrystalline Silicon Layers

1989 ◽  
Vol 157 ◽  
Author(s):  
J.M.C. England ◽  
P.J. Timans ◽  
R.A. Mcmahon ◽  
H. Ahmed ◽  
C. Hill ◽  
...  
Keyword(s):  
Grain Size ◽  
Polycrystalline Silicon ◽  
Annealing Temperature ◽  
Solid Phase ◽  
Interface Roughness ◽  
Cross Sectional ◽  
Time Resolved ◽  
Microstructural Changes ◽  
Transmission Electron

ABSTRACTMicrostructural changes occurring during the early stages of rapid thermal annealing of polycrystalline silicon bipolar emitters crucially affect the final dopant distribution and hence the performance of these devices. The first stage of annealing is epitaxial regrowth in the solid phase of the layer amorphised by the implantation. In-situ studies using time-resolved reflectivity measurements, combined with cross-sectional transmission electron microscopy of partly annealed structures, have determined the effects of initial grain size, annealing temperature and amorphising species (Si or As) on the rate of regrowth and the microstructural changes which occur during annealing. As the grain size is reduced, the regrowth rate decreases and the interface roughness increases. Arsenic implantation alters the rate of regrowth in such a manner as to produce a smoother interface than that in silicon implanted material.

In situ Time-Resolved Small-Angle X-ray Scattering Reveals the Formation Kinetics of Polyelectrolyte Complex Micelles

2019 ◽  
Author(s):  
Hao Wu ◽  
Jeffrey Ting ◽  
Siqi Meng ◽  
Matthew Tirrell
Keyword(s):  
Small Angle ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Polyelectrolyte Complex ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Kinetics Of ◽  
Ray Scattering

We have directly observed the <i>in situ</i> self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. This work has elucidated one general kinetic pathway for the process of PEC micelle formation, which provides useful physical insights for increasing our fundamental understanding of complexation and self-assembly dynamics driven by electrostatic interactions that occur on ultrafast timescales.

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.

scholarly journals Morphology and crystallization kinetics of Rubber-modified Nylon 6 Prepared by Anionic In-situ Polymerization

2020 ◽  
Vol 27 (1) ◽  
pp. 204-215
Author(s):  
Hongkai Zhao ◽  
Dengchao Zhang ◽  
Yingshuang Li
Keyword(s):  
Crystallization Kinetics ◽  
In Situ Polymerization ◽  
Good Description ◽  
Nylon 6 ◽  
Avrami Equation ◽  
Infrared Analysis ◽  
Chain Segment ◽  
The Impact ◽  
Kinetics Of

AbstractIn this work, we modified nylon 6 with liquid rubber by in-situ polymerization. The infrared analysis suggested that HDI urea diketone is successfully blocked by caprolactam after grafting on hydroxyl of HTPB, and the rubber-modified nylon copolymer is generated by the anionic polymerization. The impact section analysis indicated the rubber-modified nylon 6 resin exhibited an alpha crystal form.With an increase in the rubber content, nylon 6 was more likely to generate stable α crystal. Avrami equation was a good description of the non-isothermal crystallization kinetics of nylon-6 and rubber-modified nylon-6 resin. Moreover, it is found that the initial crystallization temperature of nylon-6 chain segment decreased due to the flexible rubber chain segment. n value of rubber-modified nylon-6 indicated that its growth was the coexistence of two-dimensional discoid and three-dimensional spherulite growth. Finally, the addition of the rubber accelerated the crystallization rate of nylon 6.

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