scholarly journals Modelling of Optical Damage in Nanorippled ZnO Produced by Ion Irradiation

Crystals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 453
Author(s):  
Redondo-Cubero ◽  
Vázquez ◽  
Jalabert ◽  
Lorenz ◽  
Sedrine
Keyword(s):  
Ion Irradiation ◽  
Ion Beam ◽  
Ion Scattering ◽  
Force Microscopy ◽  
Enhanced Absorption ◽  
High Fluences ◽  
Atomic Force ◽  
Ripple Patterns ◽  
Medium Energy Ion Scattering ◽  
Induced Changes

Here, we report on the production of nanoripples on the surface of ZnO bulk substrates by ion beam erosion with 20 keV Ar+ ions at an oblique incidence (60°). The ripple patterns, analyzed by atomic force microscopy, follow a power law dependence for both the roughness and the wavelength. At high fluences these ripples show coarsening and asymmetric shapes, which become independent of the beam direction and evidence additional mechanisms for the pattern development. The shallow damaged layer is not fully amorphized by this process, as confirmed by medium energy ion scattering. A detailed study of the damage-induced changes on the optical properties was carried out by means of spectroscopic ellipsometry. Using a 3-layer model based on Tauc-Lorenz and critical point parameter band oscillators, the optical constants of the damaged layer were determined. The results showed a progressive reduction in the refractive index and enhanced absorption below the bandgap with the fluence.

Nano-patterning on Si (100) surface under specific ion irradiation environment

MRS Advances ◽  
2019 ◽  
Vol 4 (28-29) ◽  
pp. 1673-1682 ◽  
Author(s):  
R. P. Yadav ◽  
Vandana ◽  
Jyoti Malik ◽  
Jyoti Yadav ◽  
A. K. Mittal ◽  
...  
Keyword(s):  
Energy Demand ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Normal Incidence ◽  
Rural India ◽  
Solar Systems ◽  
Force Microscopy ◽  
Atomic Force ◽  
Potential Applications ◽  
Ripple Patterns

AbstractNano-patterned surfaces have potential applications in the development of efficient solar cells through multiple internal reflections and may be used to fulfil the energy demand of rural India. Therefore, the basic understanding of growth mechanism of patterns under ion irradiation is much required. Here, the ripple patterns are grown on Si (100) surfaces for two specific ion irradiation conditions. First, the two set of samples (namely set-A and set-B) of Si (100) are irradiated by 50 keVAr+ ion beam at oblique (60°) and normal incidence, respectively, using ion fluence of 5×1016 ions/ cm2. The aim of this first stage irradiation at two different angles is the creation of different depth locations of amorphous/crystalline (a/c) interface while keeping the free surface similar in surface features, which is a crucial parameter in surface growth. Further, the sequential second stage irradiation is carried out at 60° for the same energy of Ar beam for the fluences 3×1017 to 9×1017 ions/cm2 to see the evolution of ripple patterns. Atomic force microscopy (AFM) study shows that the ripple pattern ordering is better in set-A rather than set-B. Lateral correlation length of each ripple structure surface is computed by autocorrelation function while roughness exponent is measured with height-height correlation function. Fractals behaviors of patterned on Si (100) surface are found to be sensitive to the two stage irradiation approach. The understanding of the mechanism of nano-patterns formation may be useful to develop efficient solar systems for the needs of energy in rural India.

Cleaning Procedures for UHV Cluster-tool MOS Fabrication

1992 ◽  
Vol 259 ◽  
Author(s):  
C J Sofield ◽  
M P Murrell ◽  
S Sugden ◽  
M Heyns ◽  
S Verhaverbeke ◽  
...  
Keyword(s):  
Breakdown Strength ◽  
Electrical Performance ◽  
Ion Scattering ◽  
Cross Sectional ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Medium Energy Ion Scattering ◽  
Physical And Chemical ◽  
Cluster Tool

ABSTRACTWe have investigated the effect on a silicon surface of both wet chemical and cluster-tool UV/ozone cleaning, prior to UHV processing to fabricate MOS test structures. The physical and chemical condition of the Si surface has been examined by Scanning Tunnelling and Atomic Force Microscopy (STM, AFM) and Medium Energy Ion Scattering (MEIS). After MOS fabrication some of the structures were examined by Cross-sectional Transmission Electron Microscopy (TEM). The electrical performance of the MOS test sets were characterized by breakdown voltage measurements.We have found correlations between the electrical performance of the MOS devices, the structure of the Si surface prior to oxidation, and the details of the UHV fabrication technique. In particular any MOS device fabricated on a Si surface thermally cleaned in UHV prior to oxidation has a poor breakdown strength. We have found that this is the result of the formation of silicon carbide on the Si surface at high temperature and the subsequent local disruption of the oxidation step of MOS fabrication by the SiC. A UHV cleaning procedure has been developed to avoid this C contamination problem.

Study of Swift Heavy Ion Irradiation Induced Nanophases of TiO2

2013 ◽  
Vol 24 ◽  
pp. 133-139 ◽  
Author(s):  
Madhavi Thakurdesai ◽  
A. Mahadkar ◽  
Varsha Bhattacharyya
Keyword(s):  
Thin Films ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Heavy Ion ◽  
High Energy ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Non Equilibrium

Ion beam irradiation is a unique non-equilibrium technique for phase formation and material modification. Localized rise in temperature and ultra fast (~1012 s) dissipations of impinging energy make it an attractive tool for nanostructure synthesize. Dense electronic excitation induced spatial and temporal confinement of high energy in a narrow dimension leads the system to a highly non-equilibrium state and the system then relaxes dynamically inducing nucleation of nanocrystals along the latent track. In the present investigation, amorphous thin films of TiO2 are irradiated by 100 MeV Ag ion beam. These irradiated thin films are characterized by Atomic Force Microscopy (AFM), Glancing Angle X-ray Diffraction (GAXRD), Transmission Electron Microscopy (TEM) and UV-VIS absorption spectroscopy. AFM and TEM studies indicate formation of circular nanoparticles of size 10±2 nm in a film irradiated at a fluence of 1×1012 ions.cm-2. Nanophase formation is also inferred from the blueshift observed in UV-VIS absorption band edge.

Extending AFM Phase Image of Nanocomposite Structures to 3D using FIB

2012 ◽  
Vol 1421 ◽  
Author(s):  
Russell J. Bailey ◽  
Remco Geurts ◽  
Debbie J. Stokes ◽  
Frank de Jong ◽  
Asa H. Barber
Keyword(s):  
Phase Contrast ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Polymer Nanocomposite ◽  
Three Dimensions ◽  
Phase Image ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mechanical Information ◽  
Nanocomposite Structures

ABSTRACTThe mechanical behavior of nanocomposites is critically dependent on their structural composition. In this paper we use Focused Ion Beam (FIB) microscopy to prepare surfaces from a layered polymer nanocomposite for investigation using phase contrast atomic force microscopy (AFM). Phase contrast AFM provides mechanical information on the surface examined and, by combining with the sequential cross-sectioning of FIB, can extend the phase contract AFM into three dimensions.

Biophysical Modeling of Fragment Length Distributions of DNA Plasmids after X and Heavy-Ion Irradiation Analyzed by Atomic Force Microscopy

2008 ◽  
Vol 169 (6) ◽  
pp. 649-659 ◽  
Author(s):  
Thilo Elsässer ◽  
Stephan Brons ◽  
Katarzyna Psonka ◽  
Michael Scholz ◽  
Ewa Gudowska-Nowak ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Fragment Length ◽  
Ion Irradiation ◽  
Heavy Ion ◽  
Biophysical Modeling ◽  
Force Microscopy ◽  
Heavy Ion Irradiation ◽  
Atomic Force

Fabrication of Ga-templates Using a Focused Ion Beam

2009 ◽  
Vol 1228 ◽  
Author(s):  
Hao Wang ◽  
Greg C. Hartman ◽  
Joshua Williams ◽  
Jennifer L. Gray
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Processing Conditions ◽  
New Materials ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nitridation Process ◽  
Microscopy Characterization ◽  
Device Technology

AbstractThere are many factors that have the potential to limit significant advances in device technology. These include the ability to arrange materials at shrinking dimensions and the ability to successfully integrate new materials with better properties or new functionalities. To overcome these limitations, the development of advanced processing methods that can organize various combinations of materials at nano-scale dimensions with the necessary quality and reliability is required. We have explored using a gallium focused ion beam (FIB) as a method of integrating highly mismatched materials with silicon by creating template patterns directly on Si with nanoscale resolution. These templates are potentially useful as a means of locally controlling topography at nanoscale dimensions or as a means of locally implanting Ga at specific surface sites. We have annealed these templates in vacuum to study the effects of ion dosage on local Ga concentration and topography. We have also investigated the feasibility of creating Ga nanodots using this method that could eventually be converted to GaN through a nitridation process. Atomic force microscopy and electron microscopy characterization of the resulting structures are shown for a variety of patterning and processing conditions.

Direct Measurement of Ion Beam Induced, Nanoscale Roughening of GaN

2005 ◽  
Vol 864 ◽  
Author(s):  
Bentao Cui ◽  
P. I. Cohen ◽  
A. M. Dabiran
Keyword(s):  
Ion Beam ◽  
High Energy ◽  
Surface Relaxation ◽  
Surface Roughening ◽  
High Energy Electron ◽  
Force Microscopy ◽  
Atomic Force ◽  
Continuum Equation ◽  
Argon Ions ◽  
Nanoscale Patterns

AbatractThe formation of ion induced nanoscale patterns such as ripple, dots or pores can be described by a linear continuum equation consisting of a surface roughening term due to curvature-dependent sputtering or asymmetric attachment of vacancies, and a surface smoothing term due to thermal or ion-induced diffusion. By studying ion-induced dimple volume change using atomic force microscopy, we show a method to measure the ion-roughening coefficient. Using this method, we found the roughening coefficient í was 45 nm2/sec at 730K for initial ion etchings with 300 eV Argon ions. Cathodoluminescence measurements indicated Ga-vacancy formation during ion bombardment. The activation energy for surface relaxation after ion etching was about 0.12 eV as measured by reflection high energy electron diffraction.

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