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

AbstractIon beam induced epitaxial crystallization of Au and Ag doped amorphous Si results in segregation and trapping of the impurity. Combining the measured interface velocity and impurity profiles in segregation simulations provides a measure of the segregation coefficient k during growth. To adequately match the experimental profiles, k must increase during the early stage of growth until saturating at a temperature dependent value. This segregation process cannot be explained within standard models where k depends on the inteface velocity (kinetic trapping) or the interface impurity concentration (thermodynamic solubility). Instead the data suggests that the number of trapping sites at the interface increases during the initial stages of ion beam induced growth. We present several possible mechanisms for this trapping increase and discuss their significance in ion beam and thermal epitaxy models.

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Changing Segregation Coefficients During Ion Beam Induced Epitaxy of Amorphous Si

MRS Proceedings ◽

10.1557/proc-201-363 ◽

1990 ◽

Vol 201 ◽

Author(s):

J. S. Custer ◽

Michael O. Thompson ◽

D. C. Jacobson ◽

J. M. Poate

Keyword(s):

Early Stage ◽

Ion Beam ◽

Interface Velocity ◽

Segregation Coefficient ◽

Temperature Dependent ◽

Segregation Process ◽

Standard Models ◽

Amorphous Si ◽

Kinetic Trapping ◽

Impurity Profiles

AbstractIon beam induced epitaxial crystallization of Au and Ag doped amorphous Si results in segregation and trapping of the impurity. Combining the measured interface velocity and impurity profiles in segregation simulations provides a measure of the segregation coefficient k during growth. To adequately match the experimental profiles, k must increase during the early stage of growth until saturating at a temperature dependent value. This segregation process cannot be explained within standard models where k depends on the inteface velocity (kinetic trapping) or the interface impurity concentration (thermodynamic solubility). Instead the data suggests that the number of trapping sites at the interface increases during the initial stages of ion beam induced growth. We present several possible mechanisms for this trapping increase and discuss their significance in ion beam and thermal epitaxy models.

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Crystallization Kinetics of Fe-DOPED A1203

MRS Proceedings ◽

10.1557/proc-357-201 ◽

1994 ◽

Vol 357 ◽

Cited By ~ 1

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.

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

MRS Proceedings ◽

10.1557/proc-439-137 ◽

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.

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High Concentrations of Erbium In Crystal Silicon by Thermal Or Ion-Beam-Induced Epitaxy of Erbium-Implanted Amorphous Silicon

MRS Proceedings ◽

10.1557/proc-301-101 ◽

1993 ◽

Vol 301 ◽

Cited By ~ 3

Author(s):

J. S. Custer ◽

A. Polman ◽

E. Snoeks ◽

G. N. van den Hoven

Keyword(s):

Single Crystal ◽

Amorphous Silicon ◽

Solid Phase ◽

Ion Beam ◽

Solid Phase Epitaxy ◽

Crystal Silicon ◽

Epitaxial Crystallization ◽

Amorphous Si ◽

High Concentrations ◽

Er Doped

ABSTRACTSolid phase epitaxy and ion-beam-induced epitaxial crystallization of Er-doped amorphous Si are used to incorporate high concentrations of Er in crystal Si. During solid phase epitaxy, substantial segregation and trapping of Er is observed, with maximum Er concentrations trapped in single crystal Si of up to 2 × 1020 /cm3. Ion-beam-induced regrowth results in very little segregation, with Er concentrations of more than 5 × 1020 /cm3 achievable. Photoluminescence from the incorporated Er is observed.

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

MRS Proceedings ◽

10.1557/proc-438-119 ◽

1996 ◽

Vol 438 ◽

Cited By ~ 4

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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High Concentrations of Erbium in Crystal Silicon by Thermal or Ion-Beam-Induced Epitaxy of Erbium-Implanted Amorphous Silicon

MRS Proceedings ◽

10.1557/proc-298-429 ◽

1993 ◽

Vol 298 ◽

Author(s):

J. S. Custer ◽

A. Polman ◽

E. Snoeks ◽

G. N. van den Hoven

Keyword(s):

Single Crystal ◽

Amorphous Silicon ◽

Solid Phase ◽

Ion Beam ◽

Solid Phase Epitaxy ◽

Crystal Silicon ◽

Epitaxial Crystallization ◽

Amorphous Si ◽

High Concentrations ◽

Er Doped

AbstractSolid phase epitaxy and ion-beam-induced epitaxial crystallization of Er-doped amorphous Si are used to incorporate high concentrations of Er in crystal Si. During solid phase epitaxy, substantial segregation and trapping of Er is observed, with maximum Er concentrations trapped in single crystal Si of up to 2 x 1020 /cm3. Ion-beam-induced regrowth results in very little segregation, with Er concentrations of more than 5 X 1020 /cm3 achievable. Photoluminescence from the incorporated Er is observed.

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High Resolution In Situ TEM Studies of Silicide-Mediated Crystallization of Amorphous Silicon

MRS Proceedings ◽

10.1557/proc-321-579 ◽

1993 ◽

Vol 321 ◽

Cited By ~ 1

Author(s):

C. Hayzelden ◽

J. L. Batstone

Keyword(s):

Electron Microscopy ◽

High Resolution ◽

Solid Phase ◽

In Situ Tem ◽

Solid Phase Epitaxy ◽

High Quality ◽

Transmission Electron ◽

Ledge Growth ◽

Amorphous Si

ABSTRACTWe report in situ high resolution transmission electron microscopy studies of NiSi2-Medi-ated crystallization of Amorphous Si. Compared to conventional solid phase epitaxy of (111) Si, an enhancement of the growth rate by three orders of magnitude was observed and high quality twin-free needles of <111> Si were formed. Crystallization occurred via a ledge growth mechanism at the epitaxial Type A NiSi2/crystalline Si (111) interface. A Model for NiSi2-Mediated crystallization of Amorphous Si involving the passage of kinks along <110> ledges at the NiSi2/crystalline Si (111) interface is proposed.

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