The Effect of Impurities in the SPE Kinetics in GaAs

1985 ◽  
Vol 52 ◽  
Author(s):  
C. Licoppe ◽  
Y. I. Nissim ◽  
C. Meriadec
Keyword(s):  
Solid Phase ◽  
Intrinsic Property ◽  
Interface Structure ◽  
Interface Evolution ◽  
Time Resolved ◽  
Substitutional Impurity ◽  
Effect Of Impurities ◽  
Interface Roughening ◽  
Kinetics Of ◽  
Crystal Interface

ABSTRACTSolid phase epitaxial (SPE) growth of ion implanted GaAs layers has been studied using the time resolved reflectivity technique. A series of implanted impurities have been selected to study the dependance of the nature of the impurity on the growth kinetics. It has been found that the activation energy and the kinetics of growth were independant on the choice of implanted substitutional impurity. Only impurities such as Argon were responsible of a large decrease in the regrowth rate. The same technique is shown to bring informations on the amorphous-crystal interface structure during growth. From these informations it has been possible to show that interface roughening occured during SPE in (100) GaAs. This interface evolution is an intrinsic property of the implanted GaAs material.

The Effect of Hydrogen on the Kinetics of Solid Phase Epitaxy in Amorphous Silicon

1990 ◽  
Vol 205 ◽  
Author(s):  
J. A. Roth ◽  
G. L. Olson ◽  
D. C. Jacobson ◽  
J. M. Poate ◽  
C. Kirschbaum
Keyword(s):  
Growth Rate ◽  
Solid Phase ◽  
Intrinsic Value ◽  
Amorphous Layer ◽  
Inert Gas ◽  
Solid Phase Epitaxy ◽  
Depth Profiles ◽  
Kinetics Of ◽  
Crystal Interface ◽  
Good Agreement

AbstractThis paper discusses the intrusion of H into a-Si layers during solid phase epitaxy and the effect of this H on the growth kinetics. We show that during annealing in the presence of water vapor, H is continuously generated at the oxidizing a-Si surface and diffuses into the amorphous layer, where it causes a reduction in the epitaxial growth rate. The measured variation of growth rate with the depth of the amorphous/crystal interface is correlated with the concentration of H at the interface. The diffusion coefficient for H in a-Si is determined by comparing measured depth profiles with calculated values. Hydrogen intrusion is observed even in layers annealed in vacuum and in inert gas ambients. Thin (<;5000 Åthick) a-Si layers are especially susceptible to this effect, but we show that in spite of the presence of H the activation energy for SPE derived earlier from thin-layer data is in good agreement with the intrinsic value obtained from thick, hydrogen-free layers.

scholarly journals Effect of Non-Hydrostatic Stress on Kinetics and Interfacial Roughness During Solid Phase Epitaxial Growth in Si

1996 ◽  
Vol 441 ◽  
Author(s):  
William Barvosa-Carter ◽  
Michael J. Aziz
Keyword(s):  
Growth Rate ◽  
Epitaxial Growth ◽  
Uniaxial Compression ◽  
Solid Phase ◽  
Hydrostatic Stress ◽  
Uniaxial Stress ◽  
Cross Sectional ◽  
Time Resolved ◽  
Crystal Interface

AbstractWe report preliminary in-situ time-resolved measurements of the effect of uniaxial stress on solid phase epitaxial growth in pure Si (001) for the case of stress applied parallel to the amorphous-crystal interface. The growth rate is reduced by the application of uniaxial compression, in agreement with previous results. Additionally, the velocity continues to decrease with time. This is consistent with interfacial roughening during growth under stress, and is supported by both reflectivity measurements and cross-sectional TEM observations. We present a new kinetically-driven interfacial roughening mechanism which is consistent with our observations.

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.

In Situ Time-Resolved Reflectivity Measurements of Growth Kinetics During Solid Phase Epitaxy: A Tool To Estimate Interface Non Planarity During Growth

1985 ◽  
Vol 51 ◽  
Author(s):  
C. Licoppe ◽  
Y.I. Nissim
Keyword(s):  
Laser Annealing ◽  
Solid Phase ◽  
Growth Front ◽  
Interface Roughness ◽  
Analytical Determination ◽  
Interface Evolution ◽  
Time Resolved ◽  
First Case ◽  
Reflected Light ◽  
Inhomogeneous Temperature

ABSTRACTThe time resolved reflectivity technique is shown to give informations on the amorphous-crystalline interface evolution during solid phase epitaxial (SPE) regrowth in semiconductors. Two specific cases have been treated here. The first case is encountered in laser annealing when the growth front exhibits a curvature due to the combination of an inhomogeneous temperature distribution and a steep dependence of SPE growth rates with temperature. A computer simulation is carried out from an analytical determination of the laser induced temperature profiles to shape up the resultinq reflectivity signal. The second case is obtained when there is an evolution of interface roughness during regrowth. In order to simulate this effect a simple model is developed to treat the influence of diffusion of the reflected light at the interface, on the reflectivity modulation during SPE regrowth.

Effects of Impurities on the Kinetics of Nucleation and Growth in Amorphous Silicon

1986 ◽  
Vol 74 ◽  
Author(s):  
J. A. Roth ◽  
G. L. Olson
Keyword(s):  
Nucleation Rate ◽  
Solid Phase ◽  
Nucleation And Growth ◽  
Crystallization Time ◽  
Crystallite Growth ◽  
Impurity Effects ◽  
Time Resolved ◽  
Uniform Distributions ◽  
Amorphous Si ◽  
Kinetics Of

AbstractThe effects of intentionally introduced impurities on the crystallization time, nucleation rate and crystallite growth velocity during solid phase random crystallization of amorphous Si thin films have been determined. Films deposited in UHV onto oxidized Si wafers were subjected to multiple energy ion implantation to introduce uniform distributions of P, B, As, O or F at 0.1–1.0 at.%. Crystallization times and growth velocities were determined over the temperature range 650 to 850°C from time-resolved reflectivity measurements, and nucleation rates were determined from these data using a classical, steady state nucleation and growth model. Strong impurity effects are observed: P, B and As all decrease the nucleation rate but accelerate the growth of crystallites, whereas both 0 and F retard growth while enhancing nucleation. The largest effects are for P, which reduces the nucleation rate more than 100 times at 1% concentration, and F, which increases the rate by roughly the same amount.

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.

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