Extrinsic Gettering of Copper in Silicon: Heterogeneous Precipitation on Near-Surface Dislocations

1990 ◽  
Vol 209 ◽  
Author(s):  
P.M. Rice ◽  
M.J. Kim ◽  
R.W. Carpenter
Keyword(s):  
Point Defects ◽  
Precipitation Reaction ◽  
Strain Fields ◽  
Near Surface ◽  
Heterogeneous Precipitation ◽  
Planar Arrays ◽  
Unknown Composition

ABSTRACTCopper was precipitated on extrinsic near-surface dislocations in {100} Si wafers. Several types of precipitates were heterogeneously nucleated on low index planar arrays. Large crystalline precipitates with visible strain fields proved to bea silicide. Large weakly diffracting precipitates without strain fields proved to be voids. Small, thin, partially crystalline particles of unknown composition also precipitated on the arrays. Point defects played an important role in the precipitation reaction.

Analysis of 2D and 3D defects associated with precipitation of Cu in silicon

1991 ◽  
Vol 49 ◽  
pp. 870-871
Author(s):  
P.M. Rice ◽  
MJ. Kim ◽  
R.W. Carpenter
Keyword(s):  
Colony Growth ◽  
Dark Field ◽  
Dark Side ◽  
Silicide Phase ◽  
Strain Fields ◽  
Near Surface ◽  
Unknown Composition ◽  
Secondary Precipitates ◽  
20 Nm ◽  
2D And 3D

Extrinsic gettering of Cu on near-surface dislocations in Si has been the topic of recent investigation. It was shown that the Cu precipitated hetergeneously on dislocations as Cu silicide along with voids, and also with a secondary planar precipitate of unknown composition. Here we report the results of investigations of the sense of the strain fields about the large (~100 nm) silicide precipitates, and further analysis of the small (~10-20 nm) planar precipitates.Numerous dark field images were analyzed in accordance with Ashby and Brown's criteria for determining the sense of the strain fields about precipitates. While the situation is complicated by the presence of dislocations and secondary precipitates, micrographs like those shown in Fig. 1(a) and 1(b) tend to show anomalously wide strain fields with the dark side on the side of negative g, indicating the strain fields about the silicide precipitates are vacancy in nature. This is in conflict with information reported on the η'' phase (the Cu silicide phase presumed to precipitate within the bulk) whose interstitial strain field is considered responsible for the interstitial Si atoms which cause the bounding dislocation to expand during star colony growth.

Phase Transformations and Ageing Phenomena in Copper-Nickel-Manganese Alloys

1982 ◽  
Vol 21 ◽  
Author(s):  
A.E. Weatherill ◽  
R.A. Buckley
Keyword(s):  
Grain Boundaries ◽  
Discontinuous Precipitation ◽  
Alloy System ◽  
Precipitation Reaction ◽  
Heterogeneous Precipitation ◽  
Manganese Alloys ◽  
Discontinuous Precipitation Reaction ◽  
The Subject ◽  
Binary Alloy System ◽  
Nickel Manganese

The pseudo-binary alloy system extending between copper and the intermetallic NiMn was first shown by Dean et al. [1,2] to yield a series of age hardenable alloys. The alloy containing 20% each of Ni and Mn has the best combination of strength and toughness and has been the subject of more recent studies [3,4]. The phase transformation associated with ageing in quenched Cu-NiMn alloys is precipitation of the ordered tetragonal (Llo) phase, (⊖) based on NiMn, from an fcc solid solution. Generally three modes of transformation occur depending on composition and temperature. An intragranular precipitate of fine coherent particles of ⊖, or a cellular or discontinuous precipitation reaction emanating from the grain boundaries, or heterogeneous precipitation of ⊖ at the grain boundaries.

DYNAMIC DRAG OF DISLOCATION BY POINT DEFECTS IN NEAR-SURFACE CRYSTAL LAYER

2009 ◽  
Vol 23 (16) ◽  
pp. 2041-2047 ◽  
Author(s):  
V. V. MALASHENKO
Keyword(s):  
Drag Force ◽  
Point Defects ◽  
Edge Dislocation ◽  
Crystal Layer ◽  
Near Surface ◽  
Dislocation Glide ◽  
Surface Crystal

The effect of the surface on edge dislocation glide in the crystal with point defects both on the surface and in the bulk is studied theoretically. It is shown that the drag force of dislocation can be reduced by the image forces to several orders of magnitude in nanoscale region.

Evolution of Defect and Impurity Profile During High Dose Co Implantation into Si at Elevated Temperatures

1993 ◽  
Vol 320 ◽  
Author(s):  
S. Schippel ◽  
A. Witzmann
Keyword(s):  
Point Defects ◽  
Elevated Temperatures ◽  
Rutherford Backscattering Spectrometry ◽  
High Dose ◽  
Impurity Profile ◽  
Gaussian Shape ◽  
Near Surface ◽  
Gaussian Distributions ◽  
Transmission Electron ◽  
Effective Center

ABSTRACT<111> -Si was implanted with 250 keV Co ions at a target temperature of 350°C. The ion dose was varied between 1 × 1014 cm−2 and 2 × 1017 cm−2. The evolution of the defect and impurity profile was investigated by Rutherford Backscattering Spectrometry (RBS), channeling and transmission electron microscopy (TEM).Up to a dose of 1 × 1015 Co cm−2 no defects can be detected. At higher Co doses, we find correlated defects in the center of the Co distribution and point defects in the region below. Moreover, damage accumulation at the surface is observed. The concentration of defects increases with increasing ion dose and reaches its level of saturation at a dose of 2 × 1016 cm−2.The Co profiles of samples implanted at 350°C differ considerably from the Gaussian shape. The near surface and the back flank are parts of Gaussian distributions. However, the standard deviation of the near surface flank is always smaller than that of the back flank. Moreover, the distributions show tails into the substrate at depths > 320 nm. This proves that radiation damage acts as an effective center for the nucleation of CoSi2.During annealing we find a redistribution of Co towards the defective regions for Co doses between 1 × 1016 cm−2 and 5 × 1016 cm−2.

Influence of the Temperature of Implantation on the Morphology of Defects in MeV Implanted GaAs.

1989 ◽  
Vol 147 ◽  
Author(s):  
G. Braunstein ◽  
Samuel Chen ◽  
S.-Tong Lee ◽  
G. Rajeswaran.
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Point Defects ◽  
Room Temperature ◽  
Surface Region ◽  
Amorphous Region ◽  
Liquid Nitrogen Temperature ◽  
Dislocation Loops ◽  
Near Surface ◽  
Epitaxial Regrowth

AbstractWe have studied the influence of the temperature of implantation on the morphology of the defects created during 1-MeV implantation of Si into GaAs, using RBS-channeling and TEM. The annealing behavior of the disorder has also been investigated.Implantation at liquid-nitrogen temperature results in the amorphization of the implanted sample for doses of 2×1014 cm−2 and larger. Subsequent rapid thermal annealing at 900°C for 10 seconds leads to partial epitaxial regrowth of the amorphous layer. Depending on the implantation dose, the regrowth can proceed from both the front and back ends of the amorphous region or only from the deep end of the implanted zone. Nucleation and growth of a polycrystalline phase occurs concurrently, limiting the extent of the epitaxial regrowth. After implantation at room temperature and above, two distinct types of residual defects are observed or inferred: point defect complexes and dislocation loops. Most of the point defects disappear after rapid thermal annealing at temperatures ≥ 700°C. The effect of annealing on the dislocation loops depends on the distance from the surface of the sample. Those in the near surface region disappear upon rapid thermal annealing at 700°C, whereas the loops located deeper in the sample grow in size and begin to anneal out only at temperatures in excess of 900°C. Implantation at temperatures of 200 - 300°C results in a large reduction in the number of residual point defects. Subsequent annealing at 900°C leads to a nearly defect-free surface region and, underneath that, a buried band of partial dislocation loops similar to those observed in the samples implanted at room temperature and subsequently annealed.

Evolution of Defect and Impurity Profile During High Dose Co Implantation into Si at Elevated Temperatures

1993 ◽  
Vol 316 ◽  
Author(s):  
S. Schippel ◽  
A. Witzmann
Keyword(s):  
Point Defects ◽  
Elevated Temperatures ◽  
Rutherford Backscattering Spectrometry ◽  
High Dose ◽  
Impurity Profile ◽  
Gaussian Shape ◽  
Near Surface ◽  
Gaussian Distributions ◽  
Transmission Electron ◽  
Effective Center

ABSTRACTȥ111Ɂ -Si was implanted with 250 keV Co ions at a target temperature of 350°C. The ion dose was varied between 1×1014 cm-2 and 2×1017 cm-2 . The evolution of the defect and impurity profile was investigated by Rutherford Backscattering Spectrometry (RBS), channeling and transmission electron microscopy (TEM).Up to a dose of 1 × 1015 Co cm-2 no defects can be detected. At higher Co doses, we find correlated defects in the center of the Co distribution and point defects in the region below. Moreover, damage accumulation at the surface is observed. The concentration of defects increases with increasing ion dose and reaches its level of saturation at a dose of 2 × 1016 cm-2.The Co profiles of samples implanted at 350°C differ considerably from the Gaussian shape. The near surface and the back flank are parts of Gaussian distributions. However, the standard deviation of the near surface flank is always smaller than that of the back flank. Moreover, the distributions show tails into the substrate at depths > 320 nm. This proves that radiation damage acts as an effective center for the nucleation of CoSi2.During annealing we find a redistribution of Co towards the defective regions for Co doses between 1 × 1016 cm-2 and 5× 1016 cm-2.

Effect of Surface Segregation on the Temperature Dependence of Ion-Bombardment Induced Surface Morphology

1998 ◽  
Vol 527 ◽  
Author(s):  
B. Aufray ◽  
H. Giordano ◽  
V. Petrova ◽  
D. N. Seidman
Keyword(s):  
Surface Morphology ◽  
Heating Rate ◽  
Point Defects ◽  
Room Temperature ◽  
Surface Segregation ◽  
Elevated Temperatures ◽  
Rapid Heating ◽  
Ion Bombardment ◽  
Scanning Tunneling ◽  
Near Surface

ABSTRACTWe present a scanning tunneling microscopy (STM) study, performed at different elevated temperatures, on the influence of Sb surface segregation on the morphology of the (111) surface of a Cu-0.45 at.% Sb solid-solution single-crystal; the surface was initially cleaned at room temperature by Ar+ ion sputtering. Unexpectedly, when the temperature is increased from room temperature to 380°C, the typical (111) surface morphology, obtained after sputtering, evolves in two very different manners that depend on the heating rate. If the heating rate is rapid (approximately a few minutes), it evolves to a structure with large terraces, whereas if it is slow (about 10 hours) the morphology does not evolve -- i.e., it is frozen. These unexpected results are interpreted in terms of excess subsurface point defects (vacancies and self-interstitials) created during ion bombardment, which are mobile and can mediate Sb diffusion at low temperatures. This is mainly on step edges, but the point defects can precipitate out of solution, for a rapid heating rate, thereby forming small secondary clusters in the near-surface region, in which Sb atoms are trapped.

Near-Surface Formation of Dislocation Loops in Electron-Irradiated Al-Mg

1977 ◽  
Vol 35 ◽  
pp. 50-51
Author(s):  
K. H. Westmacott
Keyword(s):  
Electron Microscope ◽  
Incubation Period ◽  
Point Defects ◽  
High Voltage ◽  
Dislocation Loops ◽  
Near Surface ◽  
Surface Formation ◽  
Metal Foils ◽  
Voltage Electron ◽  
High Voltage Electron Microscope

In studies of metal foils electron irradiated in a high voltage electron microscope it is found that after a short incubation period, interstitial loops nucleate in the center of the foils and grow under continued irradiation until eventually a network is formed. Stereomicroscopy has confirmed that loops are unable to nucleate within ~0.2μ of the surface. This is because the surfaces act as good sinks for the point defects and prevent the attainment of the necessary supersaturation for loop nucleation. In the present work on Al-ll%Mg quite different behavior has been observed depending on the condition of the foil surfaces prior to the irradiation. All the irradiations were done on electropolished discs at 650 kV in the Berkeley HVEM.

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