Furnace Anneal of A–Axis Sapphire Amorphised by Indium Ion Implantation

1988 ◽  
Vol 128 ◽  
Author(s):  
D. K. Sood ◽  
D. X. Cao
Keyword(s):  
Activation Energy ◽  
Ion Implantation ◽  
Amorphous Phase ◽  
Isothermal Annealing ◽  
Amorphous Layer ◽  
Surface Layers ◽  
Epitaxial Regrowth ◽  
Rapid Diffusion ◽  
Amorphous Surface ◽  
Higher Doses

ABSTRACTIndium implantation at 77°K into a–axis sapphire to peak concentrations of 6–45 mol % In produces amorphous surface layers. Isothermal annealing in Ar at temperatures between 600–900°C shows effects strongly dependent on ion dose. At lower doses <2×1016 In/cm2, the amorphous layer undergoes epitaxial regrowth as the amorphous to crystalline interface advances out towards the surface. Regrowth velocity is high in about the first half hour of the anneal. Regrowth obeys Arrhenius behaviour with an activation energy of 0.7eV for initial faster growth and 1.28eV for further anneal times. The amorphous phase transforms directly to ⊥-A12O3 without any evidence of an intermediary γ-phase. At higher doses, epitaxial regrowth is substantially retarded and rapid diffusion of In within the amorphous phase dominates.

Crystallization, Diffusion and Phase Separation in Sapphire Amorphised by Indium Ion Implantation

1988 ◽  
Vol 100 ◽  
Author(s):  
D. X. Cao ◽  
D. K. Sood ◽  
A. P. Pogany
Keyword(s):  
Phase Separation ◽  
Ion Implantation ◽  
Isothermal Annealing ◽  
Amorphous Layer ◽  
Dose Dependence ◽  
Rapid Diffusion ◽  
Amorphous Surface ◽  
Indium Ion

ABSTRACTIndium implantation into a-axis sapphire to peak concentrations of 8–45 mol % In produces amorphous surface layers.Migration of In during isothermal annealing at 600°C shows a strong ion dose dependence. For a dose of 6×1016In/cm2, two distinct types of In migration are seen - a) rapid diffusion of In within amorphous Al2O3 and b) diffusion of In into crystalline Al2O3 underlying the amorphous layer. For doses lower than 3×1016In/cm2 , no such migration of In is seen under identical anneal conditions. However, In undergoes phase separation into crystalline In2O3 particles embedded in amorphous Al2O3 at all doses.

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.

Laser Quenching of Amorphous Si from the Melt Containing Dopants

1983 ◽  
Vol 23 ◽  
Author(s):  
S. U. Campisano ◽  
D. C. Jacobson ◽  
J. M. Poate ◽  
A. G. Cullis ◽  
N. G. Chew
Keyword(s):  
Laser Irradiation ◽  
Ruby Laser ◽  
Metal Layer ◽  
Amorphous Layer ◽  
Irradiation Condition ◽  
Uv Laser ◽  
Surface Layers ◽  
Interfacial Segregation ◽  
Amorphous Si ◽  
Amorphous Surface

ABSTRACTThe formation of amorphous Si by the quench of a thin surface layer melted by fast UV laser irradiation has been investigated. The starting (111) surface layers were either pure or doped with As, Bi, In and Te by implantation. The asimplanted samples were recrystallized by ruby laser irradiation resulting in surface accumulation of Bi,In and Te. For the same UV irradiation condition, the amorphous layer formed in As, Bi, In or Te doped Si is about twice the thickness of the amorphous layer formed on pure Si. In the presence of the surface accumulation of Bi, In or Te, the amorphization results in an inward segregation of the dopant. For In, a very thin metal layer ˜15Å thick, is formed 150Å beneath the amorphous surface. These results show that the amorphous-liquid interfacial segregation coefficients for Bi, In or Te are less than unity and that the amorphous solidification proceeds from the surface and bottom of the liquid layer.

Damage removal following low energy ion implantation

1988 ◽  
Vol 46 ◽  
pp. 906-907
Author(s):  
Edward R. Myers
Keyword(s):  
Ion Implantation ◽  
Large Scale ◽  
Solid Phase ◽  
Semiconductor Industry ◽  
Amorphous Layer ◽  
Light Ions ◽  
Large Scale Integration ◽  
Amorphous Surface ◽  
Scale Integration ◽  
Spatial Locations

Ion implantation has become the most common method of doping in the semiconductor industry. Precise concentration profiles with exact spatial locations are achievable. However, direct implantation of the desired dopant does not always meet the stringent size requirements of ultra large scale integration (ULSI). Implantation of light ions, such as boron, tend to channel down open crystallographic orientations in crystalline substrates resulting in enhanced ion penetration and an extended doping tail. Channeling can be prevented by creation of an amorphous surface layer prior to the dopant implant. The amorphous layer can be created by implanting heavy isoelectronic ions, such as Ge+, or by implanting molecular dopant ions like BF2. Solid phase epitaxial (SPE) regrowth restores the crystallinity of the amorphous layer and activates the dopant. However, the ion implantation process damages the crystalline material adjacent to the amorphous- crystalline (a/c) interface.

Amorphous Nb40ni60 produced by Ni+ ion implantation

1978 ◽  
Vol 36 (1) ◽  
pp. 388-389
Author(s):  
M. D. Rechtin ◽  
J. Vander Sande ◽  
P. M. Baldo
Keyword(s):  
Ion Implantation ◽  
Metallic Glasses ◽  
Radiation Environment ◽  
Attractive Potential ◽  
Thermal Spike ◽  
Surface Layers ◽  
Transition Metal Alloy ◽  
New Class ◽  
Mechanical Hardness ◽  
Amorphous Surface

Metallic glasses have recently evolved as an important new class of materials which can exhibit unexpected and highly desirable physical properties compared to their crystalline counterparts. Recent work on amorphous Nb40Ni60 has shown this alloy to have excellent resistance to displacement radiation damage effects to 900 K. This phenomenon, in conjunction with thermal stability to nearly 1000 K, and excellent mechanical hardness and strength, makes this refractory-transition metal alloy an attractive potential material for radiation environment applications. Some types of metallic glasses are available commercially as thin ribbons or filaments; however, the shape, size, and type of alloy available often limit their applications. In addition, ion implantation has been used to produce amorphous surface layers in some metal- metalloid systems such as Ni-P. This method of surface layer modification may be applied to unusual shapes and sizes.Furthermore, the thermal spike produced by ion implantation results in a cooling rate of ∽1014 K/sec in the vicinity of the collision cascade.

The effect of annealing environments on the epitaxial recrystallization of ion-beam-amorphized SrTiO3

1992 ◽  
Vol 7 (3) ◽  
pp. 717-724 ◽  
Author(s):  
J. Rankin ◽  
J.C. McCallum ◽  
L.A. Boatner
Keyword(s):  
Activation Energy ◽  
Solid Phase ◽  
Ion Beam ◽  
Amorphous Layer ◽  
Surface Layers ◽  
Time Resolved ◽  
Near Surface ◽  
Thermally Induced ◽  
Stage Process ◽  
Single Constant

Time-resolved reflectivity and Rutherford backscattering spectroscopy were used to investigate the effects of regrowth environments on the thermally induced solid phase epitaxial (SPE) regrowth of amorphous near-surface layers produced by ion implantation of single-crystal SrTiO3. Water vapor in the regrowth atmosphere was found to alter both the apparent rate and activation energy of the SPE regrowth. For relatively dry atmospheres, a single constant regrowth rate is observed at any given temperature, and the activation energy is 1.2 ± 0.1 eV. When the concentration of H2O vapor in the atmosphere is increased, however, the regrowth activation energy effectively decreases to ∼0.95 eV. When regrown in atmospheres containing H2O vapor, the SrTiO3 amorphous layer exhibits two distinct stages of SPE regrowth as compared to the single rate found for dry anneals. This two-stage process apparently results from the diffusion of H/OH from the regrowth atmosphere at the surface of the crystal through the amorphous layer to the regrowing crystalline/amorphous interface.

Production and Properties of Amorphous Layers on Metal Substrates by Laser and Electron Beam Melting

1981 ◽  
Vol 8 ◽  
Author(s):  
H.W. Bergmann ◽  
B.L. Mordike
Keyword(s):  
Electron Beam ◽  
Laser Beam ◽  
Single Crystals ◽  
Electron Beam Melting ◽  
Cold Working ◽  
Amorphous Layer ◽  
Laser Glazing ◽  
Surface Layers ◽  
Metal Substrates ◽  
Amorphous Surface

ABSTRACTVarious techniques of laser glazing are presented. Rules are given for the choise of systems which are suitable for producing amorphous surface layers. Methods of demonstrating the existence of a truly amorphous layer are discussed. Two examples are given: I) electron beam glazing of Ni-Nb coated single crystals 2) laser beam glazing of Fe-B coated Fe-Cr-C cold working steel.

Crystallisation and Diffusion in Oriented Sapphire Amorphised by Zinc Ion Implantation

1990 ◽  
Vol 201 ◽  
Author(s):  
L. A. Bunn ◽  
D. K. Sood
Keyword(s):  
Epitaxial Growth ◽  
Zinc Ion ◽  
High Dose ◽  
Low Doses ◽  
Surface Layers ◽  
Rapid Diffusion ◽  
High Doses ◽  
Amorphous Surface ◽  
And Diffusion ◽  
Post Implantation

AbstractHigh dose zinc implantation (1×1016 to 6×1016 ions/cm2) into c-axis sapphire at 770K produces amorphous surface layers. Post-implantation annealing at temperatures at and above 800°C show that the modes of recrystallisation are strongly dependant on ion dose. At low doses formation of crystallites of α and γ phase Al2O3 is seen, with no evidence of any planar epitaxial growth at the original crystalline-amorphous interface. The zinc is seen to diffuse isotropically within the crystallised layer and becomes partially substitutional within the crystallites. At high doses, however, the formation of crystallites is inhibited, with the layer remaining amorphous. A more rapid diffusion of zinc is seen in the amorphous Al2O3, with some of the zinc being lost at the surface.

Ion implantation of silicon wafers for defect-reduced doped layer formation with low dopant atom diffusion

1994 ◽  
Vol 9 (11) ◽  
pp. 2987-2992
Author(s):  
Naoto Shigenaka ◽  
Shigeki Ono ◽  
Tsuneyuki Hashimoto ◽  
Motomasa Fuse ◽  
Nobuo Owada
Keyword(s):  
Ion Implantation ◽  
Amorphous Phase ◽  
Amorphous Layer ◽  
Defect Layer ◽  
Silicon Wafers ◽  
Dopant Atom ◽  
Layer Formation ◽  
Atom Diffusion ◽  
Enhanced Diffusion ◽  
Dopant Atoms

A new process for ion implantation into silicon wafers was proposed. This process has an additional implantation step to form an amorphous phase. At first self-ions are implanted into a cooled wafer (< −30 °C) to form the amorphous phase, and subsequently dopant atoms are implanted to form a doped layer within the amorphous layer. After annealing above 650 °C, the silicon wafer is completely recrystallized, and no defects with sizes detectable by TEM are present near the doped layer. There is indeed a defect layer in the wafer; however, it lies along the amorphous/crystal interface that is behind the doped layer. The concentration profile of the dopant atoms is not changed during epitaxial recrystallization, and further dopant atom diffusion during annealing is limited to about 0.05 μm, because defect-enhanced diffusion does not occur. The double implantation method is considered to be effective for doped layer formation in the VLSI fabrication process.

Channeling Studies of Thermal Regrowth in Ion Damaged Graphite

1983 ◽  
Vol 27 ◽  
Author(s):  
T. Venkatesan ◽  
B. S. Elman ◽  
G. Braunstein ◽  
M. S. Dresselhaus ◽  
G. Dresselhaus
Keyword(s):  
Activation Energy ◽  
Ion Implantation ◽  
Rutherford Backscattering Spectrometry ◽  
Pyrolytic Graphite ◽  
Surface Layers ◽  
Graphitic Structure ◽  
Inert Environment ◽  
Lower Activation ◽  
Primary Ions ◽  
Lower Activation Energy

ABSTRACTThe crystallization of disordered surface layers on highly oriented pyrolytic graphite (HOPG) have been studied by Rutherford backscattering spectrometry (RBS) and channeling techniques. Disordered layers (~1000–3000Å thick) are produced on the surface of HOPG by the implantation of various ions. The disordered layers are regrown by thermal annealing of the samples in an inert environment. Isochronal anneals reveal two distinct regrowth processes: one, a rapid process of low activation energy (Ea ~ 0.15 eV) which is observed primarily in regions where the disorder is sufficient to prevent the channeling of the ions but insufficient to totally destroy the graphitic structure. This low activation energy may indicate annealing of the damage by migration of interstitials where the interstitials are the knock-on carbon atoms produced by the primary ions. A regrowth process with higher activation energy (Ea ~ 2.0 eV) occurs primarily in regions where the disorder is close to the saturation-disorder produced by ion implantation. Both the regrowth processes are epitaxial in nature and the epitaxial nature of the process may explain the much lower activation energy for 3D AB stacking as measured in ion implanted graphite when compared with results on the bulk graphitization of pyrocarbons.

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