Densification and Crystallization of Amorphous SiO2 by Neutral Beam Bombardment

1992 ◽  
Vol 284 ◽  
Author(s):  
Tatsumi Mizutani
Keyword(s):  
Electron Spectroscopy ◽  
Auger Electron ◽  
Ion Beam ◽  
High Energy ◽  
Neutral Beam ◽  
High Dose ◽  
High Energy Electron ◽  
Amorphous Sio2 ◽  
Preferential Sputtering ◽  
Spot Formation

ABSTRACTAmorphous SiO2 films formed by thermal oxidation of silicon have been bombarded by low-energy (350 — 400 eV) ion beam and neutral beam of inert atoms. The modified SiO2 layers have been characterized by Auger electron spectroscopy (AES), Rutherford backscattering spectroscopy (RBS) and reflection high energy electron diffraction (RHEED). It is shown that neutral beam bombardment does not cause preferential sputtering of oxygenfrom SiO2, whereas ion beam of the same energy causes significant preferential sputtering. For neutral bombardment, densification and crystallization of SiO2 have been observed. The formation of α-cristobalite and α-quartz from amorphous SiO2 has been observed for high dose bombardments (>1017neutrals/cm2). These densification and crystallization phenomena can be attributed to high temperature and high pressure local spot formation upon the incidence of energetic neutral atoms. For ion beam bombardments, these densification and crystallization phenomena have not been observed.

A RHEED study of Cu3Au (110) surface

1992 ◽  
Vol 50 (2) ◽  
pp. 1460-1461
Author(s):  
Yi Huang ◽  
John M. Cowley
Keyword(s):  
Electron Diffraction ◽  
Auger Electron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Room Temperature ◽  
High Energy ◽  
High Energy Electron ◽  
Ion Scattering ◽  
Long Period ◽  
The Ideal

In recent years the Cu3Au (110) surface has been studied by many authors to reveal its ordering structure and order-disorder transition phenomena. A 2×1 structure which corresponds to an ideal truncation of the ordered bulk crystal and a 4×1 reconstructed structure have been observed. Using ion scattering methods, McRae et al have determined the Au fractions in the first and the second layer at room temperature, which deviate from the ideal bulk value and indicate the segregation of Au to the surface. But the question how the atoms are rearranged in the 4×1 structure and why some of the Au stays in the second layer have not been answered. Another important question about Cu3Au (110) surface is whether the long period ordering structure (LPS) exists on the surface. In present work the Cu3Au (precise composition Cu71.7Au28.3) (110) surface is studied with Auger electron Spectroscopy (AES) and Reflection High Energy Electron Diffraction (RHEED) which have not been used to study the Cu3Au surface before.

Effect of Sulfur Surface Structure on Nucleation of Oxide Seed Layers on Textured Metals for Coated Conductor Applications

2001 ◽  
Vol 689 ◽  
Author(s):  
C. Cantoni ◽  
D. K. Christen ◽  
A. Goyal ◽  
L. Heatherly ◽  
G. W. Ownby ◽  
...  
Keyword(s):  
Electron Spectroscopy ◽  
Seed Layer ◽  
Auger Electron ◽  
High Energy ◽  
Coated Conductor ◽  
High Energy Electron ◽  
Bulk Metal ◽  
Biaxial Texture ◽  
Seed Layers

ABSTRACTWe present a study of the {100}<100> biaxially textured Ni (001) surface and oxide seed layer nucleation by in situ reflection high-energy electron diffraction and Auger electron spectroscopy. Our observations revealed the existence of a c(2×2) superstructure on the textured Ni surface due to segregation of sulfur contained in the bulk metal. The sulfur superstructure promotes the epitaxial (002) nucleation of seed layers such as Y2O3-stabilized ZrO2 (YSZ) and CeO2 on the metal and optimizes the biaxial texture necessary for high Jc superconductors on RABiTS.

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.

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