bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetics of Graphitization of White Cast Iron
Authors: Takahashi Ryoji
Published: March 2011

It is well known that the gaseous elements have detrimental effects on the annealability of white cast iron for malleablizing. The present knowledge, however, is based on the white cast iron containing about 1.0 % Si. Therefore the author made a series of experiments by using the white east irons with silicon content ranging from 1.0 % to 1.8 %, and carr ied out multiple regression analyses of the measurements. The statistically meaningsful results can be summarized as follows:

1) In the silicon range of 1. 01 ∼ 1. 60%, the first stage graphitization is retarded by the soluble nitrogen. However, when silicon exceeds 1. 6 %, the opposite is true.

2) In the silicon range of 1. 01 ∼ 1. 40 %, the second stage graphitization is retarded by the soluble nitrogen. The degree of' the retardation increases as the specimens contain less silicon. When more than 1. 40 % Si is present, the second stage graphitization proceeds independently of soluble nitrogen content.

3) Oxygen does not at. all influence the first stage graphitization, while the second stage graphitization is slightly retarded by oxygen. This is due to nodule count, which decreases as oxygen content increases.
Effect of Nickel and Aluminium on Solid State Transformations in SG Iron
Authors: Ganguli A. C. , Chakrabarti A. K. , Dasgupta S. C.
Published: March 2011

The individual and combined addition of nickel and aluminium to S.g. iron influences several solid state transformations. Nickel depresses the temperature range for reversion of ferrite and pearlite to austenite on heating, while aluminium raises it. Combined addition of nickel and aluminium restores the temperature range closer to that for unalloyed iron. But nickel enhances the kinetics of ferritisation during tempering and weakly retards recrystallisation of ferrite grains. Aluminium strongly retards both the ferritisation and recrystallisation processes. Ferritisation kinetics is enhanced and recrystallisation of ferrite grains is also hastened in alloys containing nickel and aluminium. Alloys containing nickel and aluminium also respond to agehardening treatment in the temperature range 450–550°C after a solution treatment-cum-ferritising anneal at 700°C. On the basis of X-ray diffraction and electron microscopic studies, a probable mechanism of ageing has been proposed.
Influences of Silicon and Phosphorus Contents and Cooling Rate on JIC Fracture Toughness of Ferritic Spheroidal Graphite Cast Iron
Authors: Komatsu Shinichiro , Shiota Toshio
Published: March 2011

The influences of silicon and phosphorus contents and cooling rate on JIC fracture toughness of ferritic spheroidal graphite cast iron were investigated by 15mm thick compact tension test-pieces. The JIC values were measured by means of the R-curve method for most cases at 20°C, and by means of the maximum J value method for the cases at -100° C. The results obtained are summarized as follows. At 20WC, the specimens with silicon contents less than 3.2% showed the ductile Load-COD relations, but a specimen with 3.5%Si showed a brittle Load-COD relation and the JIC decreased greatly. Increasing phosphorus content between 0.006% and 0.26% made the JIC value decrease gradually and made the slope of the R-curve decrease greatly. Difference in cooling rate produced differences in graphite nodule diameters and ferrite grain sizes. At 20°C, the larger the specimen's average graphite nodule diameter was, the larger the JIC value was. At -100° C, the Jic values of all the specimens tested decreased largely, and the influences of these factors became very different from those at 20° C.
Influence of Trace Elemients Oh Graphite Forms in Cast Iron
Authors: Bhavsar R. D. , Blake N. W. , Ghoreshy B. , Smith T. W.
Published: March 2011

Synthetic and commercial Fe-C-Si irons have been frozen under controlled conditions after vacuum purification in order to correlate graphite forms with freezing conditions and alloy composition. It was found that graphite morphology was influenced prirmarily by the sulphur and oxygen contents and the rate of cooling. The various modes of graphite growth are discussed, particularly the appearance of the coral and compacted graphite surfaces at high magnification after the addition of oxygen or nitrogen.
The Physical Chemistry of Inoculation of Cast Iron
Authors: Gadd M. A. , Bennett G. H. J.
Published: March 2011

A theoretical analysis of inoculation shows that homogeneous nucleation of CaO, CaS, Al2O3and ZrO2is possible arid subsequent heterogeneous nucleation of silicates yields substrates for graphite growth. Excessive silicate growth leading to separation of nuclei could result in fade.

Results show that CaO/CaS embyros are most effective via silicate formation, Zr and Al control fade arido xidation enhances inoculation and fade. Added stable oxides give only limited inoculation.
Time-Resolved X-Ray Studies During Pulsed-Laser Irradiation of
Ge
Authors: Tischler J.Z. , Larson B.C. , Mills D.M.
Published: March 2011

Synchrotron x-ray pulses from the Cornell High Energy Synchrotron Source
(CHESS) have been used to carry out nanosecond resolution measurements of
the temperature distrubutions in Ge during UV pulsed-laser irradiation. KrF
(249 nm) laser pulses of 25 ns FWHM with an energy density of 0.6 J/cm2 were
used. The temperatures were determined from x-ray Bragg profile measurements
of thermal expansion induced strain on <111> oriented Ge. The data
indicate the presence of a liquid-solid interface near the melting point,
and large (1500-4500°C/pm) temperature gradients in the solid; these Ge
results are analagous to previous ones for Si. The measured temperature
distributions are compared with those obtained from heat flow calculations,
and the overheating and undercooling of the interface relative to the
equilibrium melting point are discussed.
Ultrafast Phase Transition of GaAs Surfaces Irradiated by
Picosecond Laser Pulses
Authors: Liu J.M. , Malvezzi A.M. , Bloembergen N.
Published: March 2011

Detailed analysis of the second harmonic signals in reflection from
crystalline GaAs surfaces reveals that the structural transition associated
with surface melting occurs in less than 2 ps. Preliminary results of
picosecond time-resolved reflectivity measurements are also presented.
Effects of Arsenic Doping on the Solidification Dynamics of
Pulsed-Laser-Melted Silicon
Authors: Thompson Michael O. , Peercy P. S. , Tsao J. Y.
Published: March 2011

The effects of arsenic doping on the solidification dynamics during pulsed
melting of silicon have been studied using the transient conductance
technique. At As concentrations below 1 at.%, the incorporation of As into
the Si lattice results in negligible differences in the solidification
dynamics. Between 2 and 7 at.% As, however, the interface velocity is
dramatically modified as the liquid-solid interface crosses the As
containing region. These velocity changes are consistent with a reduced
melting temperature for Si-As alloys. For concentrations of 11 at.% As, the
depression in the melting temperature is sufficient to allow the surface to
solidify while considerable melt remains buried within the sample. At 16
at.%, the melting temperature is drastically reduced and internal nucleation
of melt occurs prior to normal surface melting.
Effects of Impurities on the Competition between Solid Phase
Epitaxy and Random Crystallization In Ion-Implanted Silicon
Authors: Olson G.L. , Roth J.A. , Rytz-Froidevaux Y. , Narayan J.
Published: March 2011

The temperature dependent competition between solid phase epitaxy and random
crystallization in ion-implanted (As+, B+,
F+, and BF2+) silicon films is investigated. Measurements of time-resolved
reflectivity during cw laser heating show that in the As+,
F+, and BF2+-implanted layers (conc 4×1020cm-3)
epitaxial growth is disrupted at temperatures 1000°C. This effect is not
observed in intrinsic films or in the B+-implanted layers.
Correlation with results of microstructural analyses and computer simulation
of the reflectivity experiment indicates that disruption of epitaxy is
caused by enhancement of the random crystallization rate by arsenic and
fluorine. Kinetics parameters for the enhanced crystallization process are
determined; results are interpreted in terms of impurity-catalyzed
nucleation during the random crystallization process.
Raman Measurements on Graphite Modified by High Power Laser
Irradiation
Authors: Steinbeck J. , Braunstein G. , Dresselhaus M.S. , Elman B.S. , Venkatesan T.
Published: March 2011

The behavior of highly anisotropic materials under short pulses of high
power laser irradiation has been studied by irradiating highly oriented
pyrolytic graphite (HOPG) with 30 nsec Ruby-laser pulses with energy
densities between 0.1 and 5.0J/cm2. Raman spectroscopy has been
used to investigate the laser-induced modifications to the crystalline
structure as a function of laser energy density of the laser pulse. A Raman
microprobe was used to investigate the spatial variations of these
near-surface regions. The irradiation of HOPG with energy densities above ~
0.6J/cm2 leads to the appearance of the ~ 1360 cm-1
disorder-induced line in the first order Raman spectrum. The intensity of
the ~ 1360cm-1 line increases with increasing laser energy
density. As the energy density of the laser pulse reaches about
1.0J/cm2, the ~ 1360cm-1 line and the ~
1580cm-1 Raman-allowed mode broaden and coalesce into a broad
asymmetric band, indicating the formation of a highly disordered region,
consistent with RBS-channeling measurements. However, as the laser energy
density of the laser pulses is further increased above 3.0J/cm2,
the two Raman lines narrow and can again be resolved suggesting
laser-induced crystallization. The Raman results are consistent with high
resolution electron microscopy observations showing the formation of
randomly oriented crystallites. Raman Microprobe spectra revealed three
separate regions of behavior: (i) an outer unirradiated region where the
material appears HOPG-like with a thin layer of material coating the
surface, (ii) an inner irradiated region where the structure is uniform, but
disordered, and (iii) an intermediate region between the other regions where
the structure is highly disordered. The changes in structure of the inner
region are consistent with the behavior observed with RBS and conventional
Raman spectra. The identification of an amorphous carbon-like layer on the
outer region is consistent with a large thermomechanical stress at the
graphite surface, introduced by the high power laser pulse, and known to
occur in metals.
Calculations on Multi-Pulse, Laser-Induced Diffusion and
Evaporation Loss of Arsenic and Boron in Silicon
Authors: Tan H.S. , Ong C.K.
Published: March 2011

A dopant redistribution model that has the dopant diffusion equation
partially solved analytically before engaging numerical method in its final
solution was formulated. The model which included an evaporation loss
mechanism for the near-surface dopants was then employed in the theoretical
fitting of the measured As and ? redistributed profiles in Si due to single
and ten-pulse laser irradiations. All the dopant profiles computed were in
good agreement with the measured SIMS data. The values of dopant diffusion
coefficients Dℓ in liquid Si that were deduced presently from the
dopant profile fitting were (3.2 00B1 0.3) ×
10-4-cm2s-1 for As and (4.0 00B1 0.4) ×
10-4-cm2s-1 for ? respectively.
Comparison to the reported experimental values of Dℓ was also
made.
A Study of Electrically Active Defects Induced by Pulsed
Electron Beam Annealing In (100) N-Type Virgin Silicon
Authors: Doghmane M.S. , Barbier D. , Laugier A.
Published: March 2011

Au/Si Schottky contacts have been used as test structures to investigate
defects induced in virgin C.Z (100) N-type silicon after irradiation with a
12 to 20 KeV mean energy electron beam pulse. A thin and highly damaged
surface layer was observed from a fluence threshold of 1 J/cm2.
In addition electron traps were detected in the PEBA induced melting layer
with concentrations in the 1012-1013 cm-3
range. Their depth profiles have been related to the PEBA induced melting
layer thickness. Quenching of multidefect complexes is the most probable
mechanism for electron trap generation in the processed layer.
Strain/Damage in Crystalline Materials Bombarded by MeV Ions: Recrystallization of GaAs by High-Dose Irradiation
Authors: Wie C. R. , Vreeland T. , Tombrello T. A.
Published: March 2011

MeV ion irradiation effects on semiconductor crystals, GaAs(100) and Si (111) and on an insulating crystal CaF2(111) have been studied by the x-ray rocking curve technique using a double crystal x-ray diffractometer. The results on GaAs are particularly interesting. The strain developed by ion irradiation in the surface layers of GaAs (100) saturates to a certain level after a high dose irradiation (typically 1015/cm2), resulting in a uniform lattice spacing about 0.4% larger than the original spacing of the lattice planes parallel to the surface. The layer of uniform strain corresponds in depth to the region where electronic energy loss is dominant over nuclear collision energy loss. The saturated strain level is the same for both p-type and n-type GaAs. In the early stages of irradiation, the strain induced in the surface is shown to be proportional to the nuclear stopping power at the surface and is independent of electronic stopping power. The strain saturation phenomenon in GaAs is discussed in terms of point defect saturation in the surface layer.

An isochronal (15 min.) annealing was done on the Cr-doped GaAs at temperatures between 200° C and 700° C. The intensity in the diffraction peak from the surface strained layer jumps at 200° C < T ≤ 300° C. The strain decreases gradually with temperature, approaching zero at T ≤ 500° C.

The strain saturation phenomenon does not occur in the irradiated Si. The strain induced in Si is generally very low (less than 0.06%) and is interpreted to be mostly in the layers adjacent to the maximum nuclear stopping region, with zero strain in the surface layer. The data on CaF2have been analysed with a kinematical x-ray diffraction theory to get quantitative strain and damage depth profiles for several different doses.
High-Quality Boron and BF2+-Implanted P+ Junctions in Si Using Solid Phase
Epitaxy and Transient Annealing
Authors: Vasudev P.K. , Schmitz A.E. , Olson G.L.
Published: March 2011

We report on a systematic study of the doping profiles resulting from rapid
thermal annealing of boron and BF2+-implanted silicon samples that were preamorphized by
Si+ implantation. A two-step process consisting of an initial
solid phase epitaxial regrowth followed by a brief (~5 sec) high temperature
(1050ଌ) anneal produces extremely shallow (<1500Å) junctions with low
defect concentrations. The quality of the epitaxial regrowth is very
sensitive to implant conditions and impurity effects as deduced from
time-resolved reflectivity measurements. Using the best conditions for
implantation and solid phase crystallization, we have obtained boron-doped
regions with sheet resistivities of 40 Ω/ and BF2-doped regions
of resistivity 60 Ω/.
Applications of Beam-Solid Interactions in Semiconductor
Material and Device Processing
Authors: Fan John C. C.
Published: March 2011

Pulsed or scanned energy beams have been shown to be very useful for many
semiconductor applications, ranging from annealing of ion-implanted damage
to preparation of materials. An overview of this important field is given
and its prospects assessed.
Pulsed-CO2-Laser Annealing of Ion-Implanted
Silicon
Authors: James R.B. , Narayan J. , Christie W.H. , Eby R.E. , Holland O.W. , Wood R.F.
Published: March 2011

From studies of time-resolved reflectivity and microstructural changes, we
have obtained direct evidence of CO2 laser-induced melting above
a threshold energy density. Results of the optical measurements,
transmission electron microscopy, and secondary ion mass spectrometry are
reported. The measurements show that melt depths as deep as 1 μm can be
achieved with pulsed CO2 laser radiation. By using differential
absorption between layers with different free-carrier densities, we find
that a CO2 laser can be used to melt regions which are embedded
in the material. It is likely that this observed phenomenon is impossible to
obtain with a visible or ultraviolet laser.
Rapid Annealing of GaAs and Related Compounds
Authors: Williams J.S. , Pearton S.J.
Published: March 2011

In recent years, rapid annealing of GaAs has been employed to activate ion
implanted dopants and to produce metal-semiconductor contacts. More
recently, rapid heating techniques have been used to anneal heterostructures
without degrading requisite high mobilities of SDHT devices. This paper
reviews the various annealing regimes which are useful for heat treating
GaAs and related compounds. Examples are chosen which illustrate unique and
potentially useful features of rapid annealing.
Analysis of High Dose Implanted Silicon by High Depth Resolution
Rbs and Spectroscopic Ellipsometry and TEM
Authors: Lohner T. , Mezey G. , Fried M. , GhiţA L. , Ghiţa C. , Mertens A. , Kerkow H. , Kctai E. , PÁSzti F. , BÁNyai F. , VÍZkelethy GY. , JÁRoli E. , Gyulai J. , Somogyi M.
Published: March 2011

One of the applications of high dose ion implantation is to form surface
alloys or compound layers. The detailed characterization of such composite
structures is of great importance. This paper tries to answer the question:
how can we outline, at least, a qualitative picture from the optical
properties measured by ellipsometry of high dose Al and Sb implanted
silicon. Attempts are done to separate the effect of implanted impurities
from the dominant disorder contribution to the measured optical properties.
As the ellipsometry does not provide information enough to decide the
applicability of optical models therefore methods sensitive to the structure
(channeling and TEM) were applied too.
Ion-Projection Lithography for Submicron Modification of
Materials
Authors: Stengl G. , LÖSchner H. , Maurer W. , Wolf P.
Published: March 2011

Ion-Projection Lithography (IPL) is a future production technique for
submicron electronic devices, wich combines the advantages of e-beam and
X-ray lithography without having their disadvantages. Like electrons, ions
can be accelerated, focused and deflected, and as is the case with X-rays,
scattering in resist layers is less pronounced as for e-beams. Experimental
results of IPL obtained with an Ion-Projection-Lithography-Machine IPLM-01
are presented: Ion images of self supporting masks ten times demagnified
with a geometrical resolution < 0.25 μm printed into organic and
inorganic resist layers in high volume production oriented times.
Subboundary Spacing and Appearance in Laser Zone-Melting
Recrystallization of Silicon Onamorphous Substrate
Authors: Joly J.P. , Hode J.M. , Castagna J.C.
Published: March 2011

Recrystallized silicon films on amorphous substrates are mainly
characterized by subgrain boundaries separated by a few microns. Using
seedina from the silicon substrate (lateral epitaxy), subboundary free areas
adjacent to the seed are achieved in the direction of the beam scanninq. We
have demonstrated the large influence of the growth direction and of the
thickness of the silicon layer together on the incubation distance and on
the spacing of the subboundaries. Surprisingly, a variation of the arowth
(scan) velocity of two orders of magnitude (from 1 to 70 cm/s) has no
noticeable influence on these narameters. A I × 10 elliptical Ar+
laser beam has been used in these experiments. An interpretation of these
results in terms of lateral (step) growth and stress will be given.
SOI Technologies: Device Applications and Future
Prospects
Authors: Tsaur B-Y.
Published: March 2011

Silicon-on-insulator (SOI) technologies have four major applications:
very-large-scale integrated circuits (ICs), high-voltage ICs, large-area
ICs, and vertical ICs. This paper will review the recent progress made in
these areas and discuss the prospects of various SOI technologies for
achieving commercialization.
Electron-Phonon and Phonon-Phonon Interactions Under Laser
Annealing Conditions
Authors: Compaan Alvin
Published: March 2011

Since the first time-resolved Raman studies of pulsed laser annealing (PLA)
effects in Si, a number of cw Raman studies have been performed which
provide a much improved basis for understanding the consequences on Raman
spectra of temperature-dependent resonance effects, high carrier density
effects, phonon anharmonicity, and strain effects. Here we briefly review
these effects and then analyze the latest pulsed Raman studies of PLA
including Stokes/anti-Stokes ratios, the shift and shape of the first order
line, and time-resolved second-order spectra. The Raman data indicate the
existence of a Raman-silent phase followed by a rapidly cooling solid which
begins within 300 K of the normal melting temperature of Si. The Raman data
also give evidence of carrier densities in the recrystallizing solid of
~1−2×l019/cm3 .
Photodetector Arrays in Laser-Recrystallized Silicon Integrated
with an Optical Waveguide
Authors: Wu R.W. , Timlin H.A. , Jackson H.E. , Boyd J.T.
Published: March 2011

Integrated detection of light propagating in an optical waveguide by a
photodetector array fabricated directly on the waveguide surface is
demonstrated. Laser recrystallization of LPCVD polysilicon patterned with
periodically-spaced anti-reflection stripes is utilized. Lateral p-i-n
photodiode elements formed by ion implantation are characterized by reverse
leakage currents of < 10−11 amp and a typical breakdown
voltage of 50 volts. Optical response is found to be linear over a dynamic
range of greater than 55 dB.
Adhesion Effects on the Recrystallization of Silicon
Films
Authors: Bleil C. E. , Troxell J. R.
Published: March 2011

Laser processing of thin films of amorphous or polycrystalline silicon on
insulator substrates, such as the glass normally used for liquid crystal
displays, frequently leads to film thickness variations which are
unacceptable for device fabrication. Some thickness variations are caused by
the high surface tension of molten silicon and the poor adhesion of the
silicon to the substrate. Techniques to reduce this problem by increasing
the adhesion of the film to silicon dioxide coated Corning 7059 glass
substrates have been investigated. Two different approaches were used.
First, silicon ions were implanted into the silicon-glass interface to
increase the direct bonding of the silicon to the silicon dioxide. Second,
layers of material known to exhibit better adhesion to both silicon and
silicon dioxide were introduced between the silicon film and the glass
substrate. Both techniques produced films which, after subsequent laser
processing, showed significantly reduced thickness variations. These
procedures make it possible to laser process thin films of silicon on
Corning 7059 glass substrates under conditions which produce large grain
polysilicon films without producing unacceptably large thickness variations
or film cracking.
Solid Phase Epitaxy of UHV-Deposited Amorphous Si Over Recessed
SiO2 Layer
Authors: Tabe M. , Kunii Y.
Published: March 2011

Lateral solid phase epitaxy (L-SPE) of ultra-high-vacuum (UHV) deposited
amorphous Si (a-Si) over patterned SiO2 has been studied to produce
monocrystalline silicon-on-insulator (SOI) films. When employing
UHV-deposited a-Si, it is essential for L-SPE to reduce step height at the
pattern boundary. This is because low density a-Si including columnar voids
is formed at the step wall by the self-shadowing effect and SPE region does
not extend across the low density a-Si area. L-SPE growth distance of 7 μm
was achieved by low temperature annealing (575°C, 20 hr) on a planar
substrate with recessed SiO2 patterns. Another deposition
technique of a-Si for SPE, i.e., chemical vapor deposition is reviewed for
comparison.
Time-Resolved, Laser-Induced Phase Transformation in
Aluminum
Authors: Williamson S. , Mourou G. , Li J.C.M.
Published: March 2011

The technique of picosecond electron diffraction is used to time resolve the
laser-induced melting of thin aluminum films. It is observed that under
rapid heating conditions, the long range order of the lattice subsists for
lattice temperatures well above the equilibrium point, indicative of
superheating. This superheating can be verified by directly measuring the
lattice temperature. The collapse time of the long range order is measured
and found to vary from 20 ps to several nanoseconds according to the degree
of superheating. Two interpretations of the delayed melting are offered,
based on the conventional nucleation and point defect theories. While the
nucleation theory provides an initial nucleus size and concentration for
melting to occur, the point defect theory offers a possible explanation for
how the nuclei are originally formed.
Effect of Pressure on Self Diffusion in Crystalline Silicon
Authors: Aziz M. J. , Nygren E. , Christie W. H. , White C. W. , Turnbull D.
Published: March 2011

The effect of pressure on self diffusion in crystalline silicon is being studied using 30Si as a tracer. Diffusion experiments have been carried out in the pressure range of 1 to 35000 atmospheres at 1000°C. The 30Si is observed to diffuse faster at high pressures, indicating a negative activation volume.
Assessment of Metallic Trace Contaminants on Silicon Wafer Surfaces
Authors: Rath H. J. , Stallhofer P. , Huber D. , Eichinger P. , Ruge I.
Published: March 2011

Neutron activation, atomic absorption, and voltammetric techniques are presented as appropriate analytical tools to monitor trace amounts of metallic impurities on large diameter silicon wafers. Detection limits and results are compared for standard wafers implanted with Fe, Cu, and Ni. DLTS measurements are included for implanted and as-grown doped wafers.
The Influence of Dislocations on the Diffusion Behavior of Gold in Silicon
Authors: Stolwijk N. A. , Hölzl J.
Published: March 2011

Diffusion of gold in silicon has been studied by means of the spreading-resistance technique on dislocation-free, moderately dislocated and highly dislocated Si crystals. The penetration profiles not only show the general tendency that Au diffusion increases as a function of dislocation density, but also reveal qualitative differences between these three classes of specimens. It is demonstrated how within the framework of the kick-out model from the experimental data detailed information on both Au diffusion and Si self-diffusion can be obtained. In turn, the observed influence of dislocations on the diffusion of Au in Si represents a convincing confirmation of the kick-out mechanism.
Internal Gettering in Czochralski Silicon
Authors: Craven Robert A.
Published: March 2011

A review of the use of oxygen precipitation for the purposes of internal gettering in silicon is given. The review considers current ideas about oxygen precipitation mechanisms and the relationships between different precipitate morphologies. Two different paths for oxygen precipitation are considered, the first path being 450C thermal donor - coesite defects and the second being <100> oriented platelets. A summary of the uses of oxygen precipitation gettering in integrated circuit fabrication and a simple model for optimization of internal gettering follows the precipitation discussion.
Influence of Micro-Defect Morphology on Intrinsic Gettering Effectiveness and Durability in CMOS Epitaxial Processing
Authors: Borland John O.
Published: March 2011

The morphology of micro-defects located in the bulk of Cz-grown silicon wafers was observed to be dependent on wafer thermal history, wafer dopant species and concentration, and wafer position in the grown silicon ingot (seed, center or tail section). Intrinsic gettering effectiveness and durability due to SiOx precipitates and/or stacking faults formed during various gettering sequences were investigated. Based on preliminary results, stacking fault micro-defects combined with SiOx micro-defects are preferred for maximum durability of the intrinsic gettering mechanism.
Low Temperature Interactions Between Gold and Iron in Silicon
Authors: Brotherton S. D. , Bradley P. , Gill A.
Published: March 2011

The annealing kinetics of the gold-iron complex have been studied over the temperature range from room temperature to 400°C. From a consideration of the charge states of the gold and iron centres at room temperature it was concluded that the pairing was by Coulombic attraction. The binding energy of the centre was found to be 1.22 eV.

During the annealing processes the interstitial iron was found to be precipitating and this was shown to modify the details of the growth and dissociation rates of the gold-iron complex.
Transition Metal Contamination of Epitaxial Silicon
Authors: Scott Martin P. , Caubin L. , Chen D. C. , Weber E. R. , Rose J. , Tucker T.
Published: March 2011

Deep level defects in p/p+ epitaxial silicon were characterized by deep level transient spectroscopy (DLTS). Two dominant deep level defects were found in all samples which have been identified with Fe and CrB pairs. A third deep level defect was found in most of the samples which has tentatively been identified with Ti. The concentrations of these traps were established in a large number of samples as a function of epitaxial growth condition and substrate oxygen level.
Physical Modeling of Backside Gettering
Authors: Bronner Gary B. , Plummer James D.
Published: March 2011

To understand gettering action we have modeled the diffusion of metal to a backside getter. A first order model describing the diffusion of metals to an infinite backside sink is found not to fit experimental data. To fit the data for phosphorus gettering at 1000°C and argon implantation gettering at 800°C it is necessary to also hypothesize the injection of silicon interstitials. Assuming that the diffusion of the silicon interstitials is the rate limiting step in gettering, allows one to extract the diffusion coefficient and equilibrium concentration of the interstitial. The hypothesis of silicon interstitial injection agrees with recent work on phosphorus diffusion by Fahey et. al. To test this hypothesis for heavily damaged regions we have looked at the effect of an argon implanted region on the diffusion of a phosphorus buried layer. At both 800°C and 700°C, during nitrogen anneals we see significant enhancement of the phosphorus diffusion.
Extrinsic Gettering with Epitaxial Misfit Dislocations
Authors: Salih Ali S. M. , Maszara W. , Kim H. J. , Rozgonyi G. A.
Published: March 2011

New results are presented on Ge doped Si epitaxial layers which contain interfacial misfit dislocations. Microscopic and chemical analyses showed the preferential gettering of several metallic species (Au, Cu, Ni, and Fe) at the misfit dislocations with semiquantitative correlation between dislocation density and the captured impurity concentration. Wafer curvature was measured and shown to be less than that for typical Si3N4and SiO2layers used in IC fabrication. The reduction of Schottky diode leakage current has been clearly demonstrated and attributed to gettering of residual impurities, as well as signifying that, the active surface device region is not deleteriously affected by spurious defect reactions at the buried epitaxial interface.
Stress-Assisted Diffusion of Boron and Arsenic in Silicon
Authors: Manda Michael L. , Shepard M. L. , Fair R. B. , Massoud H. Z.
Published: March 2011

The diffusion of B and As in mechanically strnsed silicon has been investigated for initial implant doses of 1013, 1014, and 1015 cm-2, over a range of annealing temperatures. At stresses near the silicon yield point, no significant enhancement or retardation was observed. This was true even in plastically deformed samples with dislocation densities >1×107 cm-2. The results are consistent with the multiple charge state vacancy model of impurity diffusion in silicon. The B diffusivity appears to agree with the accepted activation energy of 3.59 eV and pre-exponential of 3.17 cm2/sec for intrinsic B diffusion.
Enhanced Carbon Diffusion in Silicon During 900°0 Annealing
Authors: Ladd L. A. , Kalejs J. P. , Gösele U.
Published: March 2011

Enhanced diffusion of carbon Is observed to be produced during anneal ing of silicon at 900°C under conditions of surface oxidation and phosphorus in-diffusion. Silicon containing high concentrations of carbon (∼9 × 1017/cm3 substitutional) and varying levels of interstitial oxygen and differing defect concentrations has been studied. Diffusion coefficient enhancement over the value found for an anneal in an inert ambient is by a factor of three during oxidation and a factor of forty with phosphorus in-diffusion. Carbon accumulation takes place in a region 0.3–0.5 microns from the sample surface only under conditions of phosphorus in-diffusion and is attributed to carbon precipitation. A model that assumes Interactions between silicon self-interstitials and the carbon can explain both the enhanced diffusion and the carbon accumulation.
Diffusion of Boron from Polysilicon at High Concentrations
Authors: Lever R. F. , Garben B. , Hsieh C. M. , Arienzo W. A. Orr
Published: March 2011

Boron diffusion profiles in single crystal silicon from highly doped polysilicon sources have been measured using SIMS after diffusion at 950°C for various times. These data have been analyzed to determine D(c) of boron in the single crystal. It is ncrmally assumed that at high boron concentrations D increases linearly with concentration. However, the shape of these profiles indicates that for a polysilicon source, this behavior does not appear to hold. Using Bolzmann-Matano analysis, D(c) was found to be insensitive to boron concentrations above 3.0E19 atoms/cm3. The results of this analysis were confirmed by using them as input to a diffusion simulation computer program and excellent agreement with the experimental profiles was obtained. The value of D was found to be unusually high at all concentrations in the single crystal and increased almost linearly with the doping level of the polysilicon. The effect of the furnace ramp-down cycle on the profiles near the crystal surface have also been investigated.
Atom Probe Analysis of Native Oxides and the Thermal Oxide/Silicon Interface.
Authors: Grovenora C. R. M. , Cerezo A. , Smith G. D. W.
Published: March 2011

The Pulsed Laser Atom Probe has been used to determine for the first time the stoichiometry of both the native oxide on Si and of the SiO2/Si interface.
Molecular Beam Epitaxy of GexSi1-x/(Si, Ge) Strained-Layer Heterostructures and Superlattices
Authors: Bean J. C.
Published: March 2011

This paper reviews recent work on GexSi1-x/Si(100) strained-layer epitaxy and reports new findings on GexSi1-x/Si(111) and GexSil1-x/Ge(100) growth as well as results on modulation doping. Layer synthesis and evaluation techniques are described along with tabulations of strain and critical layer thickness data. Evaluation techniques include Low Energy Electron Diffraction, Rutherford backscattering, X-ray diffraction, Raman scattering and cross-sectional Transmission Electron Microscopy. Synthesized structures range from simple heterojunctions to 100 period superlattices.
Transmission Electron Microscopy of Strained-Layer Superlattices
Authors: Gibson J. M. , Treacy M. M. J. , Hull R. , Bean J. C.
Published: March 2011

Transmission electron microscopy provides a powerful means of studying compositionally modulated materials. In such materials there is usually a local variation in electron scattering power along with a lattice dilatation wave which both accompany the local composition. The most revealing geometry for studying such materials has the lattice modulation direction lying within the plane of the thin foil. However, shear stresses accompanying the dilatation wave can be significantly relaxed by the presence of the thin foil surfaces, modifying the local atomic displacement field such that it is representative of neither the bulk, nor the free unstressed material. Two pertinent semiconductor examples which we have studied are spinodally decomposed quaternary III–V layers and strainedlayer superlattices of Si/SixGe1−x. We provide experimental evidence demonstrating relaxation in these cases and a simple elasticity model to describe it. Our data and model show a thickness dependence to relaxation and can explain previously reported ‘anomalous’ lattice parameter measurements from a strained-layer superlattice [11]. In this paper we concentrate on the effects of dilatation and relaxation on imaging and diffraction from a strained-layer superlattice.
The Epitaxial Growth of Metastable Phases
Authors: Farrow Robin F. C.
Published: March 2011

Pseudomorphism, the epitaxial growth of metastable phases, is reviewed. Emphasis is given to recent developments in the qrowth and investigation of α-Sn films on InSb and CdTe since this is a case where there is a very large strain energy barrier to the metastable to stable phase transformation. As a result, pseudomorphic growth of α-Sn can be sustained to film thicknesses of ∼1 μm.

Progress towards stabilization of direct gap group IV semiconductors is discussed and possible applications of pseudomorphism considered.
Stability and Growth of Lennard-Jones Strained Layer Superlattice Interfaces
Authors: Dodson Brian W.
Published: March 2011

In the context of a model system whose atoms interact via Lennard-Jones (LJ) interatomic potentials, we have studied the stability of an initially perfect strained layer superlattice interface (SLS) and the process of growth of a mismatched layer on a substrate using Monte Carlo techniques. An initially perfect SLS interface is found to be metastable up to 12% mismatch, a much higher value than is found on real SLS systems. In contrast, we find that, within the limitations of the calculations, a perfect SLS interface cannot be grown in an LJ system. The implications of these results for understanding SLS growth processes is discussed.
Misfit Dislocations in Epitaxial Layers of SI on Gap (001) Substrates
Authors: Viegers M. P. A. , Lieuwma C. W. T. Bulle , Zalm P. C. , Maree P. M. J.
Published: March 2011

Misfit dislocations in epitaxial layers of Si grown by MBE at 570°C on GaP(001) substrates have been studied by TEM. It is found that layers as thick as 500 Å at least reside coherently on the substrate without misfit dislocations. In 1000 Å layers of Si the misfit strain is accommodated in part by 60-degree type dislocations with their Burgers vector inclined with respect to the interface, and by stacking faults intersecting the Si layer. The dislocations are dissociated into 30- and 90-degree Shockley partial dislocations. It is shown that in the case of a biaxial strain field, which is tensile in a (001)-plane, the 90-degree partial must be nucleated first. Only then can the 30-degree partial follow on the same glide plane. This geometrical effect explains the presence of dislocations as well as stacking faults in the Si layer.
The Role of Lattice Mismatch in Growth of Epitaxial Cubic Silicides on Silicon
Authors: Hamm R. A. , Vandenberg J. M. , Gibson J. M. , Tung R. T.
Published: March 2011

The lattice mismatch of single-crystal epitaxial nickel disilicide of orientation A and B on Si(111) has been measured in and out of the <111> growth direction using a four-circle X-ray diffractometer. In both directions the mismatch of the as-grown B-type film was found to be larger than for the A-type; after annealing at 800°C the mismatch of the A-type approached the value of the B-type, while the latter remained the same. This result suggests that the B-type NiSi2 film has relaxed more during growth than the A-type which can only be relieved by subsequent annealing. This difference in A- and B-type mismatch is correlated with TEM studies. The combined results provide evidence that the growth of either A or B orientation is strongly affected by the nature and density of the misfit dislocations.
In Situ Investigation of the Palladium Silicon Reaction
Authors: Smith D. A. , Psaras P. A. , Fishert I. J. , Tu K. N.
Published: March 2011

Palladium has been deposited on {1001 and t1111 oriented silicon wafers and also on polysilicon. Cross-sectional specimens for transmission electron microscopy were prepared and heated in-situ. The interfaces between silicide and silicon were rough and the volume changes accompanying heating and compound formation caused elastic strains in the substrates and in one case hillock formation in the products.
Hgl-xCdxTe-Cr Interface Reaction
Authors: Philip P. , Wall A. , Franciosi A. , Peterman D. J.
Published: March 2011

We summarize photoemission studies using Synchrotron Radiation of the formation of the HgCdTe-Cr interface at room temperature on in situcleaved single crystal substrates. Evidence is found of a Cr-Hg exchange reaction in the subsurface region. The surface and near surface layers appear completely depleted of mercury.
Epitaxy of Nb3 Sn Films on Sapphire
Authors: Marshall A. F. , Hellman F. , Oh B.
Published: March 2011

Films of Nb3Sn vapor deposited at low rates and high temperatures on (1102) sapphire form an epitaxial <100> single crystal matrix with a domain structure of misoriented regions bounded by low-angle dislocation boundaries. Nucleation of other orientations at the interface result in a highly oriented but polycrystalline film through approximately the first thousand Angstroms of film thickness. After this point random orientations become overgrown by epitaxial <100> regions. At slightly lower temperatures many small <100> grains with a second epitaxial relationship also nucleate at the interface. These rotated grains persist through greater thicknesses than random orientations. The misorientation defect structure of the single crystal matrix is analyzed by transmission electron microscopy.
Effect of Long Range Interaction on Diffusion in Cu/NiFe TernaryAlloy Composition Modulated Thin Films
Authors: Chaudhuri Jharna , Tsakalakos Thomas
Published: March 2011

Composition modulated (with wavelengths between 1.6 to 4.98 nm) Cu/NiFe ternary alloy thin films containing 53 at % Cu, 40 at % Ni, and 7 at % Fe were prdduced by the vapor-phase growth technique. The inter-diffusivities in these films were measured at temperatures 320°C, 345°C, and 400°C from the growth or decay rate of satelite peak intensities. as a function of dispersion relation B2 exhibited anomalous behavior at certain wavelengths at which an enhanced elastic modulus effect is also observed. This anomalous behavior was directly attributed to the long range interaction.
Redistribution and Influence of Arsenic in Chromium Silicide Formation
Authors: Zheng L. R. , Hung L. S. , Mayer J. W.
Published: March 2011

The redistribution of arsenic during CrSi2 formation and its influence on the growth rate of the silicide have been investigated with Rutherford backscattering and ion channeling spectroscopy and electron microscopy. Arsenic was introduced by implantation in the metal films or in the silicon substrates. When arsenic was initially in chromium, it was incorporated in CrSi2 during silicide formation and significantly reduced the reaction rate; when arsenic was initially in silicon, it accumulated at the silicon/silicide interface with a less pronounced retarding effect than that if arsenic was present in chromium. The redistribution of dopant atoms is attributed to the fact that silicon is the dominant moving species in CrSi2 formation. The influence of dopant atoms is related to their chemical and physical state.
Pd2Si on Si(111) Growth Kinetics Studied by X-Ray Diffraction
Authors: Coulman Betty , Chen Haydn
Published: March 2011

Results are presented for the kinetics of growth of Pd2Si interfacial layers obtained by an X-ray diffraction technique. Epitaxial Pd2Si films were grown on Si(111) substrates over a temperature range of 160–222°C. The parabolic rate law observed is in qualitative agreement with those reported by investigators using other techniques (RBS, AES, Electron Microprobe). There appear to be two kinetics regimes distinquished by diffusion paths with different activation energies (1.35±0.10 eV vs. 1.05± 0.10 eV). The presence of impurities and the detailed Pd 2Si microstructure will influence how the reacting species are transported through the lattice.
Surface Characterization of Arsenic Implanted Silicon (100): A New Insight into the Inhibition of Aluminum/Silicon Interdiffusion
Authors: Herbots Nicole , Gloesener D. , Van Loenen E. J. , Fischer A. E. M. J.
Published: March 2011

Arsenic segregation at Si(lO0) surfaces during annealing (890–970°C) has been studied by medium energy ion scattering (MEIS), Rutherford backscattering spectrometry (RBS), ion scattering spectrometry (ISS), and Auger electron spectroscopy (AES). The unique depth resolution of MEIS revealed that arsenic segregated in a two-dimensional layer at the clean Si surface during annealing. For a surface with a native oxide the arsenic piled up at the Si/oxide interface. This segregation peak was no longer present on the Si surface after conventional contact opening. By metallizing arsenic junctions with Al:Si, 1% it was found that a segregation annealing step inhibited Al/Si interdiffusion. Diodes as shallow as 180 nm could be metallized without spiking.
The Disordering Process in an Ll2 Ordered Alloy
Authors: Horton J. A. , Dasgupta A. , Liu C. T.
Published: March 2011

The antiphase boundary (APB) structure and the disordering process have been studied by transmission electron microscopy (TEM) in a long-rangeordered alloy with Ll2 structure and composition (Ni70Fe30)3(V58Al40Ti2). With an increase in temperature from a single-phase field into a two-phase field, disordering occurs both homogeneously within ordered domains and heterogeneously along APBs. Disordering continues by a ripening process with the disordered islands shrinking while the disordered bands on the prior APBs grow. The APBs are partially aligned on {100} while the material is single phase. As disordering proceeds, the degree of alignment of the disordered bands on {100} increases until complete alignment results. A correlation of the APB structure with room temperature mechanical properties indicates no dramatic change at the transition to the two-phase structure.
The Disordering Phase Transformation in (Ni70Fe30)3(V98-xAlxTi2) Alloys with 0 < × < 80
Authors: Dasgupta A. , Horton J. A.
Published: March 2011

The sequence of disordering transformation processes in the A3B type alloy series (Ni70Fe30)3(V98-xAlxTi2), currently under development for high-temperature structural applications, was studied by differential scanning calorimetry (DSC), x-ray diffraction, optical microscopy, and transmission electron microscopy (TEM). Results of DSC show that in all alloys there are two endothermic stages of phase transformation from the ordered to the disordered state. With increasing x, the disordering transition temperature, Tc, reaches a maximum ∼1000°C at x ≈ 50, and then decreases. Interrupted heating, followed by water quenching, was used to characterize the crystal structure and the microstructure of the intermediate phases. For the x + 20 alloy, TEM observations showed ordered regions of DO22 phase in a matrix of disordered fcc (Al) phase at intermediate temperatures. The ordered domains transformed morphologically into cuboid like regions at higher temperatures. From a combined study by all the techniques, we conclude that in alloys with x between 0 and 20, the sequence of phase transformations upon heating is: DO22 → DO22 + Al → Al, whereas in alloys with x > 40, the major sequence is Ll2 + B2 → Ll2 + Al → Al.
DO3-domain Structures in Fe3Al-X Alloys
Authors: Mendiratta Madan G. , Lipsitt Harry A.
Published: March 2011

The influence of a number ternary additions in Fe3Al upon the DO3 domain structures and DO3 → B2 transformation temperature, Tc, has been investigated. It was found that additions in (atomic percent) of 5 Ti, 5 Cr, 6 Mn, 12 Mn, 10 Ni, 3 Mo, 6 Mo, 3 Si, and 5 Si raise Tc. In the Fe-20 Al-5 Ti alloy not only is Tc raised significantly (≧ 750°C), but the DO3 antiphase domain boundaries with fault vector become highly crystallographic and are parallel to {100} planes.