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 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.

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.

Optical Waveguide Formation by Ion Implantation of Ti or Ag

1988 ◽  
Vol 100 ◽  
Author(s):  
D. B. Poker ◽  
D. K. Thomas
Keyword(s):  
Ion Implantation ◽  
Concentration Profile ◽  
Optical Waveguides ◽  
Annealing Temperature ◽  
Solid Phase ◽  
Effective Means ◽  
Complete Removal ◽  
Solid Phase Epitaxy ◽  
Annealing Temperatures ◽  
Residual Damage

ABSTRACTIon implantation of Ti into LINbO3 has been shown to be an effective means of producing optical waveguides, while maintaining better control over the resulting concentration profile of the dopant than can be achieved by in-diffusion. While undoped, amorphous LiNbO3 can be regrown by solid-phase epitaxy at 400°C with a regrowth velocity of 250 Å/min, the higher concentrations of Ti required to form a waveguide (∼10%) slow the regrowth considerably, so that temperatures approaching 800°C are used. Complete removal of residual damage requires annealing temperatures of 1000°C, not significantly lower than those used with in-diffusion. Solid phase epitaxy of Agimplanted LiNbO3, however, occurs at much lower temperatures. The regrowth is completed at 400°C, and annealing of all residual damage occurs at or below 800°C. Furthermore, the regrowth rate is independent of Ag concentration up to the highest dose implanted to date, 1 × 1017 Ag/cm2. The usefulness of Ag implantation for the formation of optical waveguides is limited, however, by the higher mobility of Ag at the annealing temperature, compared to Ti.

Kinetics of solid phase epitaxy in thick amorphous Si layers formed by MeV ion implantation

1990 ◽  
Vol 57 (13) ◽  
pp. 1340-1342 ◽  
Author(s):  
J. A. Roth ◽  
G. L. Olson ◽  
D. C. Jacobson ◽  
J. M. Poate
Keyword(s):  
Ion Implantation ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Amorphous Si ◽  
Kinetics Of

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.

Lateral Solid Phase Epitaxy of Evaporated Amorphous Si Films onto SiO2 Patterns

1983 ◽  
Vol 25 ◽  
Author(s):  
H. Yamamoto ◽  
H. Ishiwara ◽  
S. Furukawa ◽  
M. Tamura ◽  
T. Tokuyama
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Implantation ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Si Substrates ◽  
Transmission Electron ◽  
Amorphous Si ◽  
Si Films ◽  
Kinetics Of

ABSTRACTLateral solid phase epitaxy (L-SPE) of amorphous Si (a-Si) films vacuum-evaporated on Si substrates with SiO2 patterns has been investigated, in which the film first grows vertically in the regions directly contacted to the Si substrates and then grows laterally onto SiO2 patterns. It has been found from transmission electron microscopy and Nomarski optical microscopy that use of dense a-Si films, which are formed by evaporation on heated substrates and subsequent amorphization by Si+ ion implantation, is essentially important for L-SPE. The maximum L-SPE length of 5–6μm was obtained along the <010> direction after 10hourannealing at 600°C. The kinetics of the L-SPE growth has also been investigated.

Ion Implantation and Annealing of Crystalline Oxides

1985 ◽  
Vol 60 ◽  
Author(s):  
C. W. White ◽  
P. S. Sklad ◽  
L. A. Boatner ◽  
G. C. Farlow ◽  
C. J. McHargue ◽  
...  
Keyword(s):  
Activation Energy ◽  
Ion Implantation ◽  
Single Crystal ◽  
Solid Phase ◽  
Planar Interface ◽  
Solid Phase Epitaxy ◽  
Surface Layers ◽  
Α Phase ◽  
Amorphous Surface ◽  
Crystalline Oxides

AbstractThe crystallization of amorphous surface layers produced by ion implantation of single-crystal α-Al2O3 and CaTiO3 are discussed. During annealing, amorphous A12O3 converts first to the α-phase. The crystallized γ then transforms to the a-phase by the motion of a well-defined planar interface. The temperature dependence of the velocity of the γ/α interface has been measured and is characterized by an activation energy of ∼3.6 eV. In CaTiO3, crystallization of the amorphous phase takes place by solid-phase epitaxy. The velocity of the amorphous/crystal interface is characterized by an activation energy of 1.3 eV.

scholarly journals A Study of the Impact of Graphite on the Kinetics of SPS in Nano- and Submicron WC-10%Co Powder Compositions

Ceramics ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 331-363
Author(s):  
Eugeniy Lantcev ◽  
Aleksey Nokhrin ◽  
Nataliya Malekhonova ◽  
Maksim Boldin ◽  
Vladimir Chuvil'deev ◽  
...  
Keyword(s):  
Activation Energy ◽  
Solid Phase ◽  
Continuous Heating ◽  
Diffusion Creep ◽  
Hard Alloys ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
The Impact ◽  
Kinetics Of

This study investigates the impact of carbon on the kinetics of the spark plasma sintering (SPS) of nano- and submicron powders WC-10wt.%Co. Carbon, in the form of graphite, was introduced into powders by mixing. The activation energy of solid-phase sintering was determined for the conditions of isothermal and continuous heating. It has been demonstrated that increasing the carbon content leads to a decrease in the fraction of η-phase particles and a shift of the shrinkage curve towards lower heating temperatures. It has been established that increasing the graphite content in nano- and submicron powders has no significant effect on the SPS activation energy for “mid-range” heating temperatures, QS(I). The value of QS(I) is close to the activation energy of grain-boundary diffusion in cobalt. It has been demonstrated that increasing the content of graphite leads to a significant decrease in the SPS activation energy, QS(II), for “higher-range” heating temperatures due to lower concentration of tungsten atoms in cobalt-based γ-phase. It has been established that the sintering kinetics of fine-grained WC-Co hard alloys is limited by the intensity of diffusion creep of cobalt (Coble creep).

Sign in / Sign up

Export Citation Format

Share Document