The Role of Vacancies and Dopants in Si Solid-Phase Epitaxial Crystallization

1999 ◽  
Vol 557 ◽  
Author(s):  
C. M. Chen ◽  
S. Rassiga ◽  
T. Gessmann ◽  
M. P. Petkov ◽  
M. H. Weber ◽  
...  
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Solid Phase ◽  
Vacancy Concentration ◽  
Positron Annihilation Spectroscopy ◽  
Doping Profile ◽  
Solid Phase Epitaxy ◽  
Time Resolved ◽  
Defect Complexes ◽  
Impurity Defect ◽  
Phosphorus Doped

AbstractThe role and interaction of vacancies and dopants in the crystallization of amorphous Si (a-Si) by solid-phase epitaxy (SPE) was investigated. To this end, we studied: (i) the solid-phase epitaxy rate measured by time-resolved reflectivity (TRR), (ii) the dopant and carrier concentrations measured by secondary ion mass spectrometry (SIMS) and spreading resistance (SR) analysis, and (iii) the vacancy concentration measured by positron annihilation spectroscopy (PAS). Phosphorus was implanted into a-Si on Si (001), which was previously amorphized by 29Si+ implantation, to create a nonuniform P doping profile. Phosphorus doped samples compensated with a similar boron profile were also studied. Samples were vacuum annealed for various times so that the amorphous-crystal interface was stopped at various depths providing frozen frames of the SPE process. These samples were then studied with PAS to investigate the vacancy population and to identify the impurity-defect complexes. Using this method, we have observed a population of phosphorus-vacancy complexes in the epitaxial layer.

Study of Vacancy and Impurity Complexes in Si Solid-Phase Epitaxial Crystallization with Positron Annihilation Spectroscopy

2000 ◽  
Vol 610 ◽  
Author(s):  
Claudine M. Chen ◽  
Stefano Rassiga ◽  
Marc H. Weber ◽  
Mihail P. Petkov ◽  
Kelvin G. Lynn ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Solid Phase ◽  
Positron Annihilation Spectroscopy ◽  
Vacancy Defect ◽  
Silicon Substrates ◽  
Time Resolved ◽  
Defect Complexes ◽  
Impurity Defect ◽  
Boron Ions ◽  
Doping Profiles

AbstractWe investigate the residual vacancy defect species after crystallization of amorphous Si (a-Si) by solid phase epitaxy (SPE). To this end, we correlate the total and electronically-active doping concentrations measured by secondary mass spectrometry and spreading resistance analysis, and data from positron annihilation spectroscopy (PAS), which is sensitive to openvolume defects. Float-zone silicon substrates were implanted with boron, phosphorus and both phosphorus and boron ions to create nonuniform doping profiles at degenerate doping levels, after an amorphization step by 29Si+ ions. Samples were vacuum annealed at 600°C to induce SPE, and the SPE rate was measured by time-resolved reflectivity. PAS was used for identification of the impurity-defect complexes. Momentum-resolved PAS measurements enable the detection of phosphorus-vacancy (P-V) and oxygen-vacancy (O-V) complexes.

Annealing of Pb-Implanted SrTiO3 in The Presence of Water Vapour: A Study Using D218O Labelling

1991 ◽  
Vol 235 ◽  
Author(s):  
J. C. McCallum ◽  
T. W. Simpson ◽  
I. V. Mitchell ◽  
J. Rankin ◽  
L. A. Boatner
Keyword(s):  
Water Vapour ◽  
Rate Increase ◽  
Secondary Ion Mass Spectrometry ◽  
Solid Phase ◽  
Nuclear Reaction Analysis ◽  
Doubly Labelled Water ◽  
Time Resolved ◽  
Depth Profiles ◽  
Conventional Furnace ◽  
Secondary Ion

ABSTRACTWe report new measurements of the regrowth behaviour of Pb-implanted SrTiO3 crystals in the presence of water vapour. Doubly labelled water vapour, D218O, at greater than 95% enrichment in each isotope has been added to the annealing ambient and depth profiles of D and 18O have been obtained from the regrown crystals using secondary ion mass spectrometry (SIMS). The D and 18O content has also been measured by nuclear reaction analysis (NRA) using the reactions D(3He,p)4 He and 18O(p,α)15 N. The crystals were regrown in a conventional furnace under a controlled gas ambient and time-resolved optical reflectivity (TRR) was used to dynamically monitor the regrowth rate during the anneal. An enhancement of the solid-phase epitaxial regrowth rate is observed when water vapour is added to the annealing ambient. This rate increase is accompanied by incorporation of D throughout the regrown layer. 18O is incorporated into the lattice but does not appear to penetrate deep enough to influence the regrowth rate.

Effects of Impurities on the Competition between Solid Phase Epitaxy and Random Crystallization In Ion-Implanted Silicon

1984 ◽  
Vol 35 ◽  
Author(s):  
G.L. Olson ◽  
J.A. Roth ◽  
Y. Rytz-Froidevaux ◽  
J. Narayan
Keyword(s):  
Laser Heating ◽  
Crystallization Process ◽  
Solid Phase ◽  
Crystallization Rate ◽  
Solid Phase Epitaxy ◽  
Temperature Dependent ◽  
Kinetics Parameters ◽  
Time Resolved ◽  
Cw Laser ◽  
Ion Implanted

ABSTRACTThe temperature dependent competition between solid phase epitaxy and random crystallization in ion-implanted (As+, B+, F+, and BF2+) silicon films is investigated. Measurements of time-resolved reflectivity during cw laser heating show that in the As+, F+, and BF2+-implanted layers (conc 4×1020cm-3) epitaxial growth is disrupted at temperatures 1000°C. This effect is not observed in intrinsic films or in the B+-implanted layers. Correlation with results of microstructural analyses and computer simulation of the reflectivity experiment indicates that disruption of epitaxy is caused by enhancement of the random crystallization rate by arsenic and fluorine. Kinetics parameters for the enhanced crystallization process are determined; results are interpreted in terms of impurity-catalyzed nucleation during the random crystallization process.

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.

High-Quality Boron and BF2+-Implanted P+ Junctions in Si Using Solid Phase Epitaxy and Transient Annealing

1984 ◽  
Vol 35 ◽  
Author(s):  
P.K. Vasudev ◽  
A.E. Schmitz ◽  
G.L. Olson
Keyword(s):  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Impurity Effects ◽  
Solid Phase Crystallization ◽  
High Quality ◽  
Time Resolved ◽  
Boron Doped ◽  
Epitaxial Regrowth ◽  
Doping Profiles

ABSTRACTWe report on a systematic study of the doping profiles resulting from rapid thermal annealing of boron and BF2+-implanted silicon samples that were preamorphized by Si+ implantation. A two-step process consisting of an initial solid phase epitaxial regrowth followed by a brief (~5 sec) high temperature (1050ଌ) anneal produces extremely shallow (<1500Å) junctions with low defect concentrations. The quality of the epitaxial regrowth is very sensitive to implant conditions and impurity effects as deduced from time-resolved reflectivity measurements. Using the best conditions for implantation and solid phase crystallization, we have obtained boron-doped regions with sheet resistivities of 40 Ω/ and BF2-doped regions of resistivity 60 Ω/.

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.

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.

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