Study of near surface layer of graphite produced by nitrogen ion bombardment at high doses

2002 ◽  
Vol 157 (5) ◽  
pp. 493-508 ◽  
Author(s):  
L. D. Bogomolova ◽  
A. M. Borisov ◽  
N. A. Krasil'Nikova ◽  
E. S. Mashkova ◽  
A. S. Nemov ◽  
...  
Keyword(s):  
Surface Layer ◽  
Ion Bombardment ◽  
Near Surface ◽  
Nitrogen Ion ◽  
High Doses

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.

Ion Bombardment Effects on GaAs Using 100eV Nitrogen Ions

1988 ◽  
Vol 128 ◽  
Author(s):  
W. M. Lau
Keyword(s):  
Photoelectron Spectroscopy ◽  
Molecular Nitrogen ◽  
Polar Angle ◽  
Ion Bombardment ◽  
Molecular Ions ◽  
Near Surface ◽  
Nitrogen Ions ◽  
Gallium Nitrides ◽  
Nitrogen Ion ◽  
P Type

ABSTRACTThe ion bombardment effects of low energy molecular nitrogen ions (100eV) on GaAs have been investigated using in-situ polar angle dependent X-ray photoelectron spectroscopy. It was found that arsenic and gallium nitrides were formed as a result of the nitrogen ion bombardment. The ion bombardment also caused a depletion of arsenic in the near surface region. For example, with a dose of 6×1015 cm-2 of nitrogen molecular ions at 100eV, the surface structure can be described approximately as 1.5nm of Ga0.67A0.33N on GaAs. The ion bombardment moves the Fermi levels of both n-type and p-type GaAs to mid-gap. Heating the ion bombarded samples in a vacuum chamber to 500°C desorbs all arsenic nitrides but most of the gallium nitrides remain on the surface. The Fermi levels of both n-type and p-type are then stablized at about 0.4eV from the valence band maximum. A surface type-inversion of the n-type substrate is therefore induced by the nitrogen-ionbombardment/annealing treatment.

Study of concentration-depth profiles in CoSi2 near-surface layer after ion bombardment

1992 ◽  
Vol 19 (1-12) ◽  
pp. 80-82
Author(s):  
S. S. Vojtusik ◽  
S. E. Borodyansky ◽  
V. I. Zaporozhchencko
Keyword(s):  
Surface Layer ◽  
Ion Bombardment ◽  
Near Surface ◽  
Depth Profiles ◽  
Concentration Depth Profiles

Formation of Paramagnetic Defects in Oxide Glasses During the Bombardment of Their Surface with Charged Particles

1996 ◽  
Vol 465 ◽  
Author(s):  
L. D. Bogomolova ◽  
S. V. Stef Ano Vsky ◽  
Y. G. Teplyakov ◽  
S. A. Dmitriev
Keyword(s):  
Surface Layer ◽  
Point Defects ◽  
Chemical Compounds ◽  
Ion Bombardment ◽  
Heavy Ion ◽  
Oxide Glasses ◽  
Paramagnetic Resonance ◽  
Gaseous Oxygen ◽  
Near Surface ◽  
Oxygen Hole

ABSTRACTHeavy-ion bombardment of a glass surface is a conventional laboratory technique for producing damage of interest for radioactive waste encapsulation. At energy of order 100 keV such a bombardment simulates the damage produced by α-recoil nuclei and fission fragments resulting from the nuclear decay. The damage region is 100–500 nm depending on conditions of the bombardment.In the present work some results of EPR study of point defects formed in silicate, borate, borosilicate, phosphate and other oxide glasses irradiated with different charge particles (C, N, O, Ar. Mn, Cu, Pb) at energy E=150 keV and large total fluence of ions (up to 1017 cm-2) are reported. Electron paramagnetic resonance (EPR) is a very sensitive technique which gives an information on the structure of point defects and their content. It is shown that in some cases (for example, in borate glasses) the oxygen hole centers similar to ones observed in γ-irradiated glasses are formed after ion bombardment. However, in the majority of cases new defects which are not typical of γ-irradiated oxide glasses were found They were large molecular oxygen ions (O2-O3-O4-) located in the cavities formed under ion bombardment in the near surface layer of glass. It should be noted that the relative content of these defects is of the order of several tens per 1000 incident ions. This content decreases with increasing fluence and atomic mass of incident ions. It indicates indirectly that point defects are clustered when the damage of the near surface layer becomes strong. The formation of gaseous oxygen is possible in cavities of the damage surface layer.It was found that some elements (for example C, N and transition metals) form chemical compounds with oxygen. The migration of alkali ions promotes the formation of such compounds since the chemical compounds were detected by means EPR in glasses rich in alkali oxides.

Recombination Characteristics of Single-Crystalline Silicon Wafers with a Damaged Near-Surface Layer

2013 ◽  
Vol 58 (2) ◽  
pp. 142-150 ◽  
Author(s):  
A.V. Sachenko ◽  
◽  
V.P. Kostylev ◽  
V.G. Litovchenko ◽  
V.G. Popov ◽  
...  
Keyword(s):  
Surface Layer ◽  
Crystalline Silicon ◽  
Silicon Wafers ◽  
Single Crystalline Silicon ◽  
Near Surface ◽  
Single Crystalline

scholarly journals Enhanced Diffusion of Dopants in Vacancy Supersaturation Produced by MeV Implantation

1997 ◽  
Vol 469 ◽  
Author(s):  
V. C. Venezia ◽  
T. E. Haynes ◽  
A. Agarwal ◽  
H. -J. Gossmann ◽  
D. J. Eaglesham
Keyword(s):  
Surface Layer ◽  
Surface Region ◽  
Silicon On Insulator ◽  
Rich Region ◽  
Near Surface ◽  
Enhanced Diffusion ◽  
Float Zone ◽  
Transient Enhanced Diffusion

ABSTRACTThe diffusion of Sb and B markers has been studied in vacancy supersaturations produced by MeV Si implantation in float zone (FZ) silicon and bonded etch-back silicon-on-insulator (BESOI) substrates. MeV Si implantation produces a vacancy supersaturated near-surface region and an interstitial-rich region at the projected ion range. Transient enhanced diffusion (TED) of Sb in the near surface layer was observed as a result of a 2 MeV Si+, 1×1016/cm2, implant. A 4× larger TED of Sb was observed in BESOI than in FZ silicon, demonstrating that the vacancy supersaturation persists longer in BESOI than in FZ. B markers in samples with MeV Si implant showed a factor of 10× smaller diffusion relative to markers without the MeV Si+ implant. This data demonstrates that a 2 MeV Si+ implant injects vacancies into the near surface region.

Physical properties and spatial distribution of the sea ice surface layer (SSL/snow) during the autumn phase of the MOSAiC expedition

2021 ◽  
Author(s):  
Ruzica Dadic ◽  
Martin Schneebeli ◽  
Henna-Reeta Hannula ◽  
Amy Macfarlane ◽  
Roberta Pirazzini
Keyword(s):  
Surface Layer ◽  
Spatial Distribution ◽  
Sea Ice ◽  
Physical Properties ◽  
Surface Scattering ◽  
Climate Feedback ◽  
Energy Fluxes ◽  
Scattering Layer ◽  
Near Surface ◽  
Ice Surface

<p>Snow cover dominates the thermal and optical properties of sea ice and the energy fluxes between the ocean and the atmosphere, yet data on the physical properties of snow and its effects on sea ice are limited. This lack of data leads to two significant problems: 1) significant biases in model representations of the sea ice cover and the processes that drive it, and 2) large uncertainties in how sea ice influences the global energy budget and the coupling of climate feedback. The  MOSAiC research initiative enabled the most extensive data collection of snow and surface scattering layer (SSL) properties over sea ice to date. During leg 5 of the MOSAiC expedition, we collected multi-scale (microscale to 100-m scale) measurements of the surface layer (snow/SSL) over first year ice (FYI) and MYI on a daily basis. The ultimate goal of our measurements is to determine the spatial distribution of physical properties of the surface layer. During leg 5 of the MOSAiC expedition, that surface layer changed from the  surface scattering layer (SSL),   characteristic for the melt season, to an early autumn snow pack. Here,  we will present data showing both a) the physical properties and the spatial distribution of the SSL during the late melt season and b) the transition of the sea ice surface from the SSL to the fresh autumn snowpack. The structural properties of this transition period are poorly documented, and this season is critical  for the initialization of sea ice and snow models. Furthermore, these data are crucial to interpret simultaneous observations of surface energy fluxes, surface optical and remote sensing data (microwave signals in particular), near-surface biochemical activity, and to understand the sea ice  processes that occur as the sea ice transitions from melting to freezing.</p>

Deepening of domains at e-beam writing on the -Z surface of lithium niobate

2021 ◽  
Author(s):  
Lyudmila Kokhanchik ◽  
Evgenii Emelin ◽  
Vadim Vladimirovch Sirotkin ◽  
Alexander Svintsov
Keyword(s):  
Surface Layer ◽  
Electron Beam ◽  
Lithium Niobate ◽  
Electric Field ◽  
Domain Walls ◽  
Normal Component ◽  
Beam Current ◽  
Near Surface ◽  
Domain Structures ◽  
Sign Inversion

Abstract The focus of the study was to investigate the peculiarities of the domains created by electron beam (e-beam) in a surface layer of congruent lithium niobate, which comparable to a depth of electron beam charge penetration. Direct e-beam writing (DEBW) of different domain structures with a scanning electron microscope was performed on the polar -Z cut. Accelerating voltage 15 kV and e-beam current 100 pA were applied. Different patterns of local irradiated squares were used to create domain structures and single domains. No domain contrast was observed by the PFM technique. Based on chemical etching, it was found that the vertices of the domains created do not reach the surface level. The average deepening of the domain vertices was several hundred nanometers and varied depending on the irradiation dose and the location of the irradiated areas (squares) relative to each other. Computer simulation was applied to analyze the spatial distribution of the electric field in the various irradiated patterns. The deepening was explained by the fact that in the near-surface layer there is a sign inversion of the normal component of the electric field strength vector, which controls the domain formation during DEBW. Thus, with the help of e-beam, domains were created completely located in the bulk, in contrast to the domains that are nucleated on the surface of the -Z cut during the polarization inversion with AFM tip. The detected deepening of e-beam domains suggests the possibility of creating the “head-to-head” domain walls in the near-surface layer lithium niobate by DEBW.

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