Atomistic Aspects of Silicide Reactions Studied with STM

1993 ◽  
Vol 320 ◽  
Author(s):  
P. A. Bennett ◽  
S. A. Parikh ◽  
M. Y. Lee ◽  
David G. Cahill ◽  
M. Copel ◽  
...  
Keyword(s):  
Room Temperature ◽  
Lattice Gas ◽  
Bond Breaking ◽  
Prototype System ◽  
Near Surface ◽  
Metal Atoms ◽  
Temperature Deposition ◽  
Low Coverage ◽  
Stm Images ◽  
Very High

ABSTRACTWe discuss atomistic aspects of the silicide contact reaction inferred primarily from STM observations of the prototype system Co/Si(1 11). For room temperature deposition and low coverage (0.01M1) we find that metal atoms exist as near-surface interstitials within the 7×7 reconstruction. Bond breaking associated with silicide formation occurs only at higher coverages. Deposition at 320C results in flat-topped triangular islands of epitaxial CoSi2 with a metastable 7-fold (111) interface, stabilized by the lateral silicon-silicide interface along the island edges. Some islands are covered with a 2×2 array of silicon adatoms. Very high temperature annealing (1200C) results in an “impurity stabilized 1×1” surface which is in fact a lattice gas of ring-clusters that appear like tiny donuts or bagels in empty states STM images. These structures phase-separate from the clean 7×7 structure upon cooling below 850C.

A Comparative Study of Near-Surface Effects Due to Very High Fluence H+ Implantation In Single Crystal FZ, CZ, and Web SI

1983 ◽  
Vol 27 ◽  
Author(s):  
W.J. Choyke ◽  
R.B. Irwin ◽  
J.N. Mcgruer ◽  
J.R. Townsend ◽  
N.J. Doyle ◽  
...  
Keyword(s):  
Comparative Study ◽  
Single Crystal ◽  
Room Temperature ◽  
Surface Effects ◽  
Step Height ◽  
High Fluence ◽  
Near Surface ◽  
Float Zone ◽  
Very High ◽  
Oxygen Concentrations

ABSTRACTCrystals of float-zone, Czochralski, and Web Si having widely differing oxygen concentrations were imrplanted at 300°K with large fluences of hydrogen. Experiments using RBS/channeling, profilometry and microscopy are reported. For room temperature implants the step-height h, the distribution of displaced atoms ND(x) and the total number of displaced atoms/cm2 (aD) are all essentially independent of the oxygen convent of the Si.

scholarly journals Formation of Irregular Al Islands by Room-Temperature Deposition on NiAl(110)

2011 ◽  
Vol 1318 ◽  
Author(s):  
Dapeng Jing ◽  
Yong Han ◽  
Bariş Ünal ◽  
J. W. Evans ◽  
P. A. Thiel
Keyword(s):  
Room Temperature ◽  
Lattice Gas ◽  
Island Growth ◽  
Site Lattice ◽  
Adsorption Sites ◽  
Temperature Deposition ◽  
Diffusion Paths ◽  
Kinetics Of ◽  
And Diffusion ◽  
Multiple Adsorption

ABSTRACTSTM studies reveal that irregular non-equilibrium two-dimensional Al islands form during deposition of Al on NiAl(110) at 300 K. These structures reflect the multiple adsorption sites and diffusion paths available for Al adatoms on the binary alloy surface, as well as the details of inhibited edge diffusion and detachment-attachment kinetics of Al adatoms for numerous distinct step edge configurations. We attempt to capture these features by multi-site lattice-gas modeling incorporating DFT energetics for adatoms both at adsorption sites and transition states. This formulation enables description and elucidation of the observed island growth shapes.

Dislocation structures around SiO2 Particles in aged Cu-Cr-SiO2

1978 ◽  
Vol 36 (1) ◽  
pp. 594-595
Author(s):  
N.J. Long ◽  
M.H. Loretto ◽  
C.H. Lloyd
Keyword(s):  
Flow Stress ◽  
Single Crystals ◽  
Room Temperature ◽  
Thin Foil ◽  
Age Hardening ◽  
Dispersion Strengthening ◽  
Accurate Picture ◽  
The Matrix ◽  
Very High ◽  
Good Agreement

IntroductionThere have been several t.e.m. studies (1,2,3,4) of the dislocation arrangements in the matrix and around the particles in dispersion strengthened single crystals deformed in single slip. Good agreement has been obtained in general between the observed structures and the various theories for the flow stress and work hardening of this class of alloy. There has been though some difficulty in obtaining an accurate picture of these arrangements in the case when the obstacles are large (of the order of several 1000's Å). This is due to both the physical loss of dislocations from the thin foil in its preparation and to rearrangement of the structure on unloading and standing at room temperature under the influence of the very high localised stresses in the vicinity of the particles (2,3).This contribution presents part of a study of the Cu-Cr-SiO2 system where age hardening from the Cu-Cr and dispersion strengthening from Cu-Sio2 is combined.

Investigation of the Hydrogen Transport Processes in Crystalline Silicon of n-Type Conductivity

2007 ◽  
Vol 131-133 ◽  
pp. 425-430 ◽  
Author(s):  
Anis M. Saad ◽  
Oleg Velichko ◽  
Yu P. Shaman ◽  
Adam Barcz ◽  
Andrzej Misiuk ◽  
...  
Keyword(s):  
Hydrogen Concentration ◽  
Room Temperature ◽  
Crystalline Silicon ◽  
Transport Processes ◽  
Concentration Profiles ◽  
Hydrogen Transport ◽  
Hydrogen Atoms ◽  
Near Surface ◽  
Type Conductivity ◽  
Hydrogen Molecules

The silicon substrates were hydrogenated at approximately room temperature and hydrogen concentration profiles vs. depth have been measured by SIMS. Czochralski grown (CZ) wafers, both n- and p-type conductivity, were used in the experiments under consideration. For analysis of hydrogen transport processes and quasichemical reactions the model of hydrogen atoms diffusion and quasichemical reactions is proposed and the set of equations is obtained. The developed model takes into account the formation of bound hydrogen in the near surface region, hydrogen transport as a result of diffusion of hydrogen molecules 2 H , diffusion of metastable complexes * 2 H and diffusion of nonequilibrium hydrogen atoms. Interaction of 2 H with oxygen atoms and formation of immobile complexes “oxygen atom - hydrogen molecule” (O - H2 ) is also taken into account to explain the hydrogen concentration profiles in the substrates of n-type conductivity. The computer simulation based on the proposed equations has shown a good agreement of the calculated hydrogen profiles with the experimental data and has allowed receiving a value of the hydrogen molecules diffusivity at room temperature.

Molecule-Based Magnets—An Overview

MRS Bulletin ◽  
2000 ◽  
Vol 25 (11) ◽  
pp. 21-30 ◽  
Author(s):  
Joel S. Miller ◽  
Arthur J. Epstein
Keyword(s):  
Low Temperature ◽  
Vapor Deposition ◽  
Room Temperature ◽  
Chemical Vapor ◽  
Magnetic Ordering ◽  
Low Density ◽  
Materials Properties ◽  
The Common ◽  
New Processing ◽  
Very High

Molecule-based magnets are a broad, emerging class of magnetic materials that expand the materials properties typically associated with magnets to include low density, transparency, electrical insulation, and low-temperature fabrication, as well as combine magnetic ordering with other properties such as photoresponsiveness. Essentially all of the common magnetic phenomena associated with conventional transition-metal and rare-earth-based magnets can be found in molecule-based magnets. Although discovered less than two decades ago, magnets with ordering temperatures exceeding room temperature, very high (∼27.0 kOe or 2.16 MA/m) and very low (several Oe or less) coercivities, and substantial remanent and saturation magnetizations have been achieved. In addition, exotic phenomena including photoresponsiveness have been reported. The advent of molecule-based magnets offers new processing opportunities. For example, thin-film magnets can be prepared by means of low-temperature chemical vapor deposition and electrodeposition methods.

ION CHANNELING AND PIXE STUDIES OF S IMPLANTATION IN GaAs

1992 ◽  
Vol 02 (02) ◽  
pp. 151-159
Author(s):  
LIU SHIJIE ◽  
WANG JIANG ◽  
HU ZAOHUEI ◽  
XIA ZHONGHUONG ◽  
GAO ZHIGIANG ◽  
...  
Keyword(s):  
Room Temperature ◽  
Dislocation Loops ◽  
Good Recovery ◽  
Electrical Measurements ◽  
X Ray ◽  
Defect Complexes ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Activation Efficiency ◽  
Very High

GaAs (100) crystals were implanted with 100 keV S+ to a dose of 3×1015 cm−2 in a nonchanneling direction at room temperature, and treated with rapid thermal annealing (RTA). He+ Rutherford backscattering and particle-induced X-ray emission in channeling mode in combination with transmission electron microscopy (TEM) were used to study the damage and the lattice location of S atoms. It is revealed that the RTA at 950 °C for 10 sec has resulted in a very good recovery of crystallinity with a few residual defects in the form of dislocation loops, and a very high substitutionality (~90%). The activation efficiency and the Hall mobility of the implanted samples are found to be low after the electrical measurements. Based on these results an extended dopant diffusion effect for the residual defects and a correlation between the electrical properties and defect complexes are suggested.

scholarly journals Room temperature deposition of superconducting niobium nitride films by ion beam assisted sputtering

APL Materials ◽  
2018 ◽  
Vol 6 (7) ◽  
pp. 076107 ◽  
Author(s):  
Tomas Polakovic ◽  
Sergi Lendinez ◽  
John E. Pearson ◽  
Axel Hoffmann ◽  
Volodymyr Yefremenko ◽  
...  
Keyword(s):  
Room Temperature ◽  
Ion Beam ◽  
Niobium Nitride ◽  
Temperature Deposition
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