The Role of the Lattice Step in Epitaxial Growth

1999 ◽  
Vol 570 ◽  
Author(s):  
Tsu-Yi Fu ◽  
Tien T. Tsong
Keyword(s):  
Epitaxial Growth ◽  
Quantitative Information ◽  
Step Edge ◽  
Atomic Processes ◽  
Growth Modes ◽  
Diffusion Parameters ◽  
Temperature Ranges ◽  
Diffusion Paths ◽  
Field Ion Microscope

ABSTRACTSolid surfaces have many lattice steps. In epitaxy, aggregation of deposited atoms into islands or clusters during their diffusing can create many additional atomic steps. We study the effects of lattice steps on epitaxial growth in two aspects: 1. Movement of atoms across the step edge: a series of field ion microscope experiments reveal the importance of reflective and trapping properties of steps, and provide quantitative information that helps explain various growth modes observed in homoepitaxial growth. 2. Diffusion along the step edge: a number of field ion microscope experiments are done to determine diffusion parameters of a ledge atom along the step edge, and to derive the potential-energy diagram along different diffusion paths that helps explain the growth morphology. During growth, an atom undergoes a number of elementary atomic processes. Each process is characterized by a few energy parameters in bonding and diffusion. The integrated effect of all of these processes determines the growth process. We provide reliable experimental data and find the temperature ranges where various atomic processes are important

Field ion microscope investigations of atomic processes at surfaces

1989 ◽  
Vol 47 ◽  
pp. 228-229
Author(s):  
G. L. Kellogg ◽  
P. R. Schwoebel
Keyword(s):  
Single Crystal ◽  
Crystal Surface ◽  
Linear Chain ◽  
Atom Probe ◽  
Nucleation And Growth ◽  
Single Atom ◽  
Initial Structure ◽  
Atomic Processes ◽  
Single Crystal Surfaces ◽  
Field Ion Microscope

Although no longer unique in its ability to resolve individual single atoms on surfaces, the field ion microscope remains a powerful tool for the quantitative characterization of atomic processes on single-crystal surfaces. Investigations of single-atom surface diffusion, adatom-adatom interactions, surface reconstructions, cluster nucleation and growth, and a variety of surface chemical reactions have provided new insights to the atomic nature of surfaces. Moreover, the ability to determine the chemical identity of selected atoms seen in the field ion microscope image by atom-probe mass spectroscopy has increased or even changed our understanding of solid-state-reaction processes such as ordering, clustering, precipitation and segregation in alloys. This presentation focuses on the operational principles of the field-ion microscope and atom-probe mass spectrometer and some very recent applications of the field ion microscope to the nucleation and growth of metal clusters on metal surfaces.The structure assumed by clusters of atoms on a single-crystal surface yields fundamental information on the adatom-adatom interactions important in crystal growth. It was discovered in previous investigations with the field ion microscope that, contrary to intuition, the initial structure of clusters of Pt, Pd, Ir and Ni atoms on W(110) is a linear chain oriented in the <111> direction of the substrate.

Model for Epitaxial growth of Cobalt on CU(100)

1989 ◽  
Vol 160 ◽  
Author(s):  
Dimitri D. Vvedensky ◽  
Shaun Clarke
Keyword(s):  
Epitaxial Growth ◽  
Growth Kinetics ◽  
Solid Model ◽  
Free Energies ◽  
Diffusion Parameters ◽  
The Difference ◽  
Kinetics Of

AbstractThe epitaxial growth kinetics of Co on Cu(100) are investigated with a kinetic solid-on-solid model. Two effects are found to dominate the growth of this system reflecting the difference in surface free energies betweenthe two materials: the difference of diffusion parameters, and the inability of Co to wet Cu(100) at lower temperatures.

Oxide Mediated Epitaxial Growth of CoSi2 in a Single Deposition Step

1999 ◽  
Vol 564 ◽  
Author(s):  
S. Ohmi ◽  
R. T. Tung
Keyword(s):  
Single Crystal ◽  
Epitaxial Growth ◽  
Diffusion Barrier ◽  
Blocking Layer ◽  
Deposition Step

AbstractA number of modifications of the oxide-mediated epitaxy (OME) technique are presented which have enabled the growth of thick (∼25–40nm) epitaxial CoSi2 layers in a single deposition sequence. The uses of (a) a thin Ti cap, (b) a thin Ti blocking layer, (c) the codeposition of Co-rich CoSix, and (d) the co-deposition of Col−xTix. have all been shown to lead to improved epitaxial quality over the pure Co OME process, for Co thickness greater than 6nm. Essentially uniform, single crystal silicide layers of over 25nm have been grown in a single deposition step. These results are supportive of the proposed role of a diffusion barrier/kinetics retarder on the part of the interlayer in the OME and the Ti-interlayer mediated epitaxy processes.

A Pictorial Tracking of Basal Plane Dislocations in SiC Epitaxy

2010 ◽  
Vol 645-648 ◽  
pp. 271-276 ◽  
Author(s):  
Robert E. Stahlbush ◽  
Rachael L. Myers-Ward ◽  
Brenda L. VanMil ◽  
D. Kurt Gaskill ◽  
Charles R. Eddy
Keyword(s):  
Epitaxial Growth ◽  
Basal Plane ◽  
Reduction Process ◽  
Epitaxial Layers ◽  
In Situ Growth ◽  
Half Loop ◽  
Insight Into

The recently developed technique of UVPL imaging has been used to track the path of basal plane dislocations (BPDs) in SiC epitaxial layers. The glide of BPDs during epitaxial growth has been observed and the role of this glide in forming half-loop arrays has been examined. The ability to track the path of BPDs through the epitaxy has made it possible to develop a BPD reduction process for epitaxy grown on 8° offcut wafers, which uses an in situ growth interrupt and has achieved a BPD reduction of > 98%. The images also provide insight into the strong BPD reduction that typically occurs in epitaxy grown on 4° offcut wafers.

On the role of Pb in epitaxial growth of thin Co films on Cu(111)

1998 ◽  
Vol 402-404 ◽  
pp. 263-267 ◽  
Author(s):  
S Mróz ◽  
H Otop ◽  
Z Jankowski
Keyword(s):  
Epitaxial Growth

Epitaxial Growth of MG on PD(100) and AG(100): Growth Modes for Complete and Incomplete Adlayer Condensation

1997 ◽  
pp. 235-244 ◽  
Author(s):  
J. Wollschläger ◽  
F. Schäfer ◽  
D. Erdös ◽  
K. M. Schröder ◽  
M. Michailov ◽  
...  
Keyword(s):  
Epitaxial Growth ◽  
Growth Modes

scholarly journals The CasKR Two-Component System Is Required for the Growth of Mesophilic and Psychrotolerant Bacillus cereus Strains at Low Temperatures

2014 ◽  
Vol 80 (8) ◽  
pp. 2493-2503 ◽  
Author(s):  
Sara Esther Diomandé ◽  
Stéphanie Chamot ◽  
Vera Antolinos ◽  
Florian Vasai ◽  
Marie-Hélène Guinebretière ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Food Poisoning ◽  
Two Component System ◽  
Diverse Range ◽  
Component System ◽  
Content Type ◽  
Two Component ◽  
Temperature Ranges ◽  
Different Strains

ABSTRACTThe different strains ofBacillus cereuscan grow at temperatures covering a very diverse range. SomeB. cereusstrains can grow in chilled food and consequently cause food poisoning. We have identified a new sensor/regulator mechanism involved in low-temperatureB. cereusgrowth. Construction of a mutant of this two-component system enabled us to show that this system, called CasKR, is required for growth at the minimal temperature (Tmin). CasKR was also involved in optimal cold growth aboveTminand in cell survival belowTmin. Microscopic observation showed that CasKR plays a key role in cell shape during cold growth. Introducing thecasKRgenes in a ΔcasKRmutant restored its ability to grow atTmin. Although it was first identified in the ATCC 14579 model strain, this mechanism has been conserved in most strains of theB. cereusgroup. We show that the role of CasKR in cold growth is similar in otherB. cereus sensu latostrains with different growth temperature ranges, including psychrotolerant strains.

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