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.

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.

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.

Temperature And Dose Dependence of An Amorphous Layer Formed By Ion Implantation

1985 ◽  
Vol 51 ◽  
Author(s):  
Eliezer Dovid Richmond ◽  
Alvin R. Knudson
Keyword(s):  
Ion Implantation ◽  
Amorphous Layer ◽  
Dose Dependence ◽  
Layer Width ◽  
Implantation Energy ◽  
Amorphous Si ◽  
Energy Dose

ABSTRACTA model is formulated to predict the width of an amorphous layer in Si produced by ion implantation. The dependency of the amorphous Si layer width on the ion implantation energy, dose, and temperature is computed.

Inverse Ostwald Ripening and Self-Organization of Nanoclusters due to Ion Irradiation

2000 ◽  
Vol 647 ◽  
Author(s):  
K.-H. Heinig ◽  
B. Schmidt ◽  
M. Strobel ◽  
H. Bernas
Keyword(s):  
Phase Separation ◽  
Ion Implantation ◽  
Ostwald Ripening ◽  
Ion Irradiation ◽  
Experimental Studies ◽  
Self Organization ◽  
Mathematical Treatment ◽  
Thermodynamical Equilibrium ◽  
Unusual Behavior ◽  
Thermally Activated

AbstractUnder ion irradiation collisional mixing competes with phase separation if the irradiated solid consists of immiscible components. If a component is a chemical compound, there is another competition between the collisional forced chemical dissociation of the compound and its thermally activated re-formation. Especially at interfaces between immiscible components, irradiation processes far from thermodynamical equilibrium may lead to new phenomena. If the formation of nanoclusters (NCs) occurs during ion implantation, the phase separation caused by ion implantation induced supersaturation can be superimposed by phenomena caused by collisional mixing. In this contribution it will be studied how collisional mixing during high-fluence ion implantation affects NC synthesis and how ion irradiation through a layer of NCs modifies their size and size distribution. Inverse Ostwald ripening of NCs will be predicted theoretically and by kinetic lattice Monte-Carlo simulations. The mathematical treatment of the competition between irradiation-induced detachment of atoms from clusters and their thermally activated diffusion leads to a Gibbs-Thomson relation with modified parameters. The predictions have been confirmed by experimental studies of the evolution of Au NCs in SiO2 irradiated by MeV ions. The unusual behavior results from an effective negative capillary length, which will be shown to be the reason for inverse Ostwald ripening. Another new phenomenon to be addressed is self-organization of NCs in a d-layer parallel to the Si/SiO2 interface. Such d-layers were found when the damage level at the interface was of the order of 1-3 dpa. It will be discussed that the origin of the d-layer of NCs can be assigned to two different mechanisms: (i) The negative interface energy due to collisional mixing gives rise to the formation of tiny clusters of substrate material in front of the interface, which promotes heteronucleation of the implanted impurities. (ii) Collisional mixing in the SiO2produces diffusing oxygen, which may be consumed by the Si/SiO2 interface. A thin layer parallel to the interface becomes denuded of diffusing oxygen, which results in a strong pile up of Si excess. This Si excess promotes heteronucleation too. Independent of the dominating mechanism of self-organization of a d-layer of NCs, its location in SiO2 close to the SiO2/Si interface makes it interesting for non-volatile memory application.

Precipitation of highly luminescent phases from PECVD Si suboxides

2004 ◽  
Vol 832 ◽  
Author(s):  
M. Perálvarez ◽  
M. López ◽  
B. Garrido ◽  
J.R. Morante ◽  
J. Barreto ◽  
...  
Keyword(s):  
Refractive Index ◽  
Phase Separation ◽  
Ion Implantation ◽  
Composition Profile ◽  
Matrix Composition ◽  
Light Sources ◽  
The Matrix ◽  
Detailed Composition ◽  
Preparation Route

ABSTRACTSi nanoclusters (Si-nc) embedded in SiO2 present outstanding luminescent emission in the visible and are the material of choice for the realization of efficient light sources integrated with Si technology. PECVD is an attractive preparation route but there is still the need to understand how Si excess and matrix composition affect the precipitation of Si-nc and their photoluminescence (PL) efficiency. The SiOx PECVD layers studied here have a Si excess up to 50% and a thickness between 50 and 100 nm. The phase separation, precipitation and growth of the Si-nc have been achieved by annealing at 1250 °C. For reference, the same study has been performed in Si-nc/SiO2 materials synthesized by ion implantation and annealing. Refractive index and thickness measured by ellipsometry show a densification of the layers after the H release during annealing. A detailed composition profile has been determined by XPS and FTIR analyses and shows almost complete phase separation except for the interfaces, where a depletion of Si-nc is found. EFTEM demonstrates that isolated Si-nc are formed for Si excess up to 25% while for higher Si excess a continuous Si phase is observed. The PL efficiency in PECVD samples is maximized for a Si excess of 17% which is the same Si excess than that for the most emitting implanted samples. No dependence of PL efficiency has been found on the presence of Nitrogen in the matrix (up to the 10%).

scholarly journals Hardening of Nickel Alloys by Ion Implantation of Titanium and Carbon

1996 ◽  
Vol 444 ◽  
Author(s):  
S. M. Myers ◽  
D. M. Follstaedt ◽  
J. A. Knapp ◽  
T. R. Christenson
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Surface Layer ◽  
Ion Implantation ◽  
Finite Element Modeling ◽  
Yield Stress ◽  
Nickel Alloys ◽  
Element Modeling ◽  
Order Of Magnitude ◽  
Amorphous Surface

AbstractDual ion implantation of titanium and carbon was shown to produce an amorphous surface layer in annealed bulk nickel, in electroformed Ni, and in electroformed Ni7 5Fe 2 5. Diamond-tip nanoindentation coupled with finite-element modeling quantified the elastic and plastic mechanical properties of the implanted region. The amorphized matrix, with a thickness of about 100 nm, has a yield stress of approximately 6 GP and an intrinsic hardness near 16 GPa, exceeding by an order of magnitude the corresponding values for annealed bulk Ni. Implications for micro-electromechanical systems are discussed.

TEM Characterization of Arsenic and Phosphorus Implanted Silicon Devices

1997 ◽  
Vol 3 (S2) ◽  
pp. 467-468
Author(s):  
Lancy Tsung ◽  
Hun-Lian Tsai ◽  
Alwin Tsao ◽  
Makoto Takemura
Keyword(s):  
Ion Implantation ◽  
Crystalline Silicon ◽  
Source Region ◽  
Amorphous Layer ◽  
Common Source ◽  
Silicon Devices ◽  
Similar Region ◽  
Before And After ◽  
P Type ◽  
Silicon Device

Ion implantation of arsenic and phosphorus is a common practice in silicon devices for the formation of transistor source/drain regions. We used a TEM equipped with EDX capabilities to investigate effects of ion implantation in actual devices before and after annealing. A 200 kev field emission gun TEM was used in this study. Two implant cases were studied here. Both samples are p-type, (100) Si wafers.Figure 1 shows the microstructure in a common source region of a silicon device after being implanted by phosphorus (4x1014 cm−2 at 30 kv, 0°), while Figure 2 shows a similar region for arsenic implantation (5x1015 cm−2 at 45 kv, 0°). No screen layer was used during implantation. The phosphorus implant results in a ˜0.05 μm amorphous layer sandwiched between heavily damaged crystalline silicon. High resolution images reveal a rough amorphous/damaged crystalline boundary and high density defects due to silicon lattice displacements.

A Study of the Corrosion Resistance of M50NiL Bearing Steel by Ion Implantation

2014 ◽  
Vol 936 ◽  
pp. 1132-1137
Author(s):  
J. Jin ◽  
Y.B. Chen ◽  
K.W. Gao ◽  
X.l. Huang
Keyword(s):  
Corrosion Resistance ◽  
Ion Implantation ◽  
Grain Boundaries ◽  
Potentiodynamic Polarization ◽  
Corrosion Potential ◽  
Amorphous Layer ◽  
Bearing Steel ◽  
Detection Methods ◽  
Corrosion Reaction ◽  
Strengthening Phases

The corrosion resistance of metal-N double-element alternate implanted M50NiL bearing steel was investigated by potentiodynamic polarization and detection methods of SEM, XPS, AES and TEM. The results showed that ion implanted M50NiL can increase the corrosion potential of substrate, reduce the corrosion active points and inhibit the corrosion reaction induced at the grain boundaries. The formed amorphous layer and strengthening phases take main roles in improving the corrosion resistance of M50NiL bearing steel.

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