scholarly journals Intra-Cascade Surface Recombination of Point Defects During Ion Bombardment of Ge (001)

1993 ◽  
Vol 316 ◽  
Author(s):  
J. A. Floro ◽  
B. K. Kellerman ◽  
E. Chason ◽  
S. T. Picraux ◽  
D. K. Brice ◽  
...  
Keyword(s):  
Point Defects ◽  
Surface Recombination ◽  
Ion Bombardment ◽  
High Energy ◽  
Low Energy ◽  
Yield Reduction ◽  
High Energy Electron ◽  
Near Surface ◽  
Large Numbers

ABSTRACTLow energy Ar and Xe ion bombardment of Ge (001) produces large numbers of point defects on the Ge surface and in the near-surface regions. Defect concentrations on the surface are detected and quantified in real time during bombardment using in situ Reflection High Energy Electron Diffraction (RHEED). We report the energy dependence of the defect yield for 70–500 eV Ar and Xe ion bombardment, and the temperature dependence of the defect yield (defects/ion) during 200 eV ion bombardment. The defect yield drops rapidly as the substrate temperature during bombardment is varied from 175 K to 400 K. We attribute the yield reduction to surface recombination of adatoms and vacancies produced in the same collision cascade.

Simulations of Low-Energy Ion Bombardment and Epitaxial Growth

1991 ◽  
Vol 236 ◽  
Author(s):  
E. Chason ◽  
P. Bedrossian ◽  
J.Y. Tsao ◽  
B.W. Dodson ◽  
S.T. Picraux
Keyword(s):  
Epitaxial Growth ◽  
Ion Beam ◽  
Ion Bombardment ◽  
High Energy ◽  
Low Energy ◽  
High Energy Electron ◽  
Preferential Sputtering ◽  
Surface Vacancy ◽  
Atomic Coordination ◽  
Primary Interaction

AbstractWe have performed computer simulations of epitaxial growth and low-energy ion bombardment for comparison with reflection high-energy electron diffraction (RHEED) mesurements. The simulations are based on a hybrid Monte Carlo/rate equation approach which includes the processes of defect creation (adatom and surface vacancy), surface diffusion, and attachment and detachment from steps and islands. In this work, we focus on simulating the experimental observations of ion-induced RHEED oscillations and cancellation of RHEED oscillations during simultaneous ion bombardment and growth. For the interaction of the low-energy ion with the surface, we consider two mechanisms: preferential sputtering (where the sputtering cross section depends on the atomic coordination) and mobile vacancies. Our results indicate that the primary interaction of the ion beam with the surface is probably through the creation of mobile vacancies, and that the degree of preferential sputtering is not large.

Simulations of Low-Energy Ion Bombardment and Epitaxial Growth

1991 ◽  
Vol 235 ◽  
Author(s):  
E. Chason ◽  
P. Bedrossian ◽  
J. Y. Tsao ◽  
B. W. Dodson ◽  
S. T. Picraux
Keyword(s):  
Epitaxial Growth ◽  
Ion Beam ◽  
Ion Bombardment ◽  
High Energy ◽  
Low Energy ◽  
High Energy Electron ◽  
Preferential Sputtering ◽  
Surface Vacancy ◽  
Atomic Coordination ◽  
Primary Interaction

ABSTRACTWe have performed computer simulations of epitaxial growth and low-energy ion bombardment for comparison with reflection high-energy electron diffraction (RHEED) mesurements. The simulations are based on a hybrid Monte Carlo/rate equation approach which includes the processes of defect creation (adatom and surface vacancy), surface diffusion, and attachment and detachment from steps and islands. In this work, we focus on simulating the experimental observations of ion-induced RHEED oscillations and cancellation of RHEED oscillations during simultaneous ion bombardment and growth. For the interaction of the low-energy ion with the surface, we consider two mechanisms: preferential sputtering (where the sputtering cross section depends on the atomic coordination) and mobile vacancies. Our results indicate that the primary interaction of the ion beam with the surface is probably through the creation of mobile vacancies, and that the degree of preferential sputtering is not large.

Argon Ion Bombardment During Molecular Beam Epitaxy of Ge (001)

1988 ◽  
Vol 128 ◽  
Author(s):  
Eric Chason ◽  
K. M. Horn ◽  
J. Y. Tsao ◽  
S. T. Picraux
Keyword(s):  
Molecular Beam Epitaxy ◽  
Surface Morphology ◽  
Molecular Beam ◽  
Ion Beam ◽  
High Energy ◽  
Low Energy ◽  
High Energy Electron ◽  
Argon Ion Bombardment ◽  
Argon Ion

ABSTRACTUsing in situ, real-time reflection high energy electron diffraction (RHEED), we have measured the evolution of Ge (001) surface morphology during simultaneous molecular beam epitaxy and Ar ion beam bombardment. Surprisingly, low-energy Ar ions during growth tend to smoothen the surface. Bombardment by the ion beam without growth roughens the surface, but the surface can be reversibly smoothened by restoring the growth beam. We have measured the effect of such “ion beam growth smoothening” above and below the critical temperature for intrinsic growth roughening. At all measured growth temperatures the surface initially smoothens, but below the critical roughening temperature the final surface morphology is rough whereas above this temperature the final morphology is smooth.

Surface and Near-Surface Atom Dynamics During Low Energy Xe Ion Bombardment of Si and Fcc Surfaces

1990 ◽  
Vol 193 ◽  
Author(s):  
M. V. R. Murty ◽  
H. S. Lee ◽  
Harry A. Atwater
Keyword(s):  
Molecular Dynamics ◽  
Surface Layer ◽  
Ion Bombardment ◽  
Low Energy ◽  
Surface Processes ◽  
Defect Production ◽  
Near Surface ◽  
Qualitative Nature ◽  
Dynamics Simulations ◽  
Atom Dynamics

ABSTRACTSurface and near-surface processes have been studied during low energy Xe ion bombardment of Si (001) and fcc surfaces using molecular dynamics simulations. Defect production is enhanced near the surface of smooth Si (001) surfaces with respect to the bulk in the energy range 20–150 eV, but is not confined exclusively to the surface layer. The extent and qualitative nature of bombardment-induced dissociation of small fcc islands on an otherwise smooth fcc (001) surface is found to depend strongly on island cohesive energy.

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