Ion Beam Damage Research Articles

Sensitivity of near-edge x-ray absorption fine structure spectroscopy to ion beam damage in diamond films

In the present work, we study the sensitivity of the near-edge x-ray absorption fine structure (NEXAFS) spectroscopy to ion induced defects in polycrystalline diamond films. The ion bombardment of hydrogenated films is performed using 30 keV Xe+ ions at room temperature for doses ranging from 2×1013 ions/cm2, producing local point defects, to 2×1015 ions/cm2, which results in almost complete amorphization of the diamond surface. Auger electron spectroscopy measurements are not sensitive to the modifications induced by the lowest implantation dose. Whereas partial electron yield (PEY) NEXAFS measurements, applied in surface and bulk-sensitive modes, using 35, 15, and 8 eV secondary electrons, respectively, reveals the formation of a defective structure and gradual deterioration of diamond in the near-surface region. From PEY NEXAFS spectra measured using 15 eV secondary electrons, the position of C(1s) binding energy is measured. The x-ray photoelectron spectra of the samples were measured using an incident photon energy of 450 eV. It is found that the C(1s) binding energy in the implanted samples has a positive shift of 0.6–1 eV, which is indicative of transformation of diamond to disordered carbon. The high sensitivity of NEXAFS spectroscopy to point defects induced by the low dose ion implantation was reflected by a sharp reduction in the intensity of the diamond core exciton peak and by the appearance of a new spectral feature in the pre-edge region, below the C(1s)−π* transition. Analysis of the NEXAFS spectra of ion implanted films is performed on the basis of the electronic structure of diamond.

Round robin of time-of-flight secondary ion mass spectrometry damage studies of a photoimmobilized reagent on diamond surfaces designed for surface glycoengineering

Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) has previously been successfully applied to characterize the covalent grafting of N-( m-(3-(trifluoromethyl) diazirine-3-yl)phenyl)-4-maleimido-butyramide (MAD), a reagent used for immobilization of biomolecules on solid surfaces, i.e., diamond substrates. In this study, the molecule was used to compare dose-related damage data obtained on two different ToF-SIMS systems, a PHI Trift and a PHI-7200 Reflectron, after shipping identically prepared samples to two independent laboratories. The ToF-SIMS spectrum in the negative ion mode exhibits characteristic signals over a large mass range, allowing to compare spectral differences in data acquired in the static SIMS regime with the two spectrometers to differences in experimental parameters, such as detector voltages. Variations in ion beam damage were not fully reproduced by both ToF-SIMS systems, indicating limitations in the comparison of ion beam damage data using two different sets of experimental parameters. This discrepancy could be related to different mass-dependent ion transmissions of the two spectrometers. The results suggest that a model developed in the literature for the interpretation of ion dose-induced polymer damage can be successfully applied to the case of organic molecules covalently attached to a diamond surface.

Effect of Extended Defects on the Enhanced Diffusion of Phosphorus Implanted Silicon

ABSTRACTExtended defects resulting from ion implantation are believed to act in some cases as a driving force behind transient enhanced diffusion (TED). We use secondary ion mass spectrometry (SIMS) to study the diffusion enhancements of an underlying boron doped spike after creating implant damage in the near surface region. Diffusion enhancements are compared for silicon implants and phosphorus implants to distinguish between factors related to chemical species interactions versus those related to ion beam damage. Transmission electron microscopy (TEM) is used to investigate the existence and dissolution of extended defects. {311} extended defects are clearly visible in self-implanted samples but absent in phosphorus doped samples. The extended defects resulting from phosphorus implantation are small (20Å to 60Å diameter) “dot” defects barely resolvable by conventional TEM. methods. Despite the marked differences in defect morphology, diffusion enhancements in the boron marker layer are observable for both species. Results comparing the TED of a buried marker layer after P+ and Si+ show a larger overall effective diffusion length results after high dose (1x1014 cm−2) phosphorus implants. Visible defects in phosphorus implanted silicon are not the only source of TED, suggesting the existence of sub-microscopic phosphorus interstitial clusters (PIC). This provides important insight into the affect of phosphorus on TED.

Comparison of TiO2(110) Surfaces by XPS: Effects of UV Exposure, Electron Beam and Ion Beam Damage

Many studies have been carried out on rutile TiO2 since it was discovered to be a photocatalyst with relatively high efficiency for the decomposition of water. Surface defects are believed to play an important role in dissociation of absorbed water and other small molecules. Defects created on a TiO2(110) surface by thermal annealing in vacuum, or by low-density electron beam irradiation, ultraviolet illumination, and Ar+ ion bombardment, were examined by x-ray photoelectron spectroscopy (XPS). The XPS multiplex spectra of O 1s and Ti 2p peaks were collected. The experiment was carried out in a Perkin-Elmer Physical Electronics 560 Multiprobe surface analysis system with a double pass cylindrical mirror analyzer. Nonmonochromated Mg Kα x-rays were used to generate the spectra.

Selenium nanoparticles formed by ion implantation into fused silica

Selenium ions were implanted into fused silica hosts at an energy of 330 keV at fluences of 1 × 10 16, 3 × 10 16, 6 × 10 16 and 1 × 10 17 ions/cm 2. The samples containing 1 × 10 17 ions/cm 2 were annealed at 600, 800 and 1000°C for 1 h in a 5% H 2 + 95% Ar atmosphere. The electronic spectra of the as-implanted sample exhibited an absorption edge near 2.5 eV (550 nm) as compared to 1.95 for bulk trigonal or amorphous selenium. The absorption edge is shifted to the red as the samples were annealed at increasing temperatures. Infrared reflection measurements revealed a decrease in the reflectivity of a peak associated with the LO mode silica and is attributed to ion beam damage. A new peak was also observed near 1050 cm −1 for the as-implanted sample and is assigned to an Si–O-dangling bond vibration formed during ion implantation. This peak vanishes when the samples are annealed at 1000°C indicating that the Si–O–Si linkages have reformed. A redshift of the absorption edge that increases with ion dose and annealing temperature observed in the electronic spectra is attributed to quantum confinement of the photo-generated exciton. This observation is consistent with current models predicting quantum size effects in semiconductor nanocrystals.

Ion irradiation-induced amorphization of CaAl 2O 4

The relationship between irradiation-induced amorphization and glass formation was investigated with CaAl 2O 4, a highly ionic (ionicity=0.68) glass former (Al 2O 3·CaO). Samples were irradiated with 1.5 MeV Xe + from 100 to 673 K. In situ TEM was used to characterize the effects of ion beam damage and the critical temperature for amorphization, T c. The sample became amorphous at 1.2 × 10 14 Xe +/cm 2 at room temperature. T c is 733 K. Two other phases, Al 2O 3·SiO 2 (andalusite) and Al 2O 3·MgO (spinel), are compared with Al 2O 3·CaO. Based on a cascade-quenching model, the susceptibility to radiation-induced amorphization is proposed to be related to the tendency toward glass formation.

Ion beam enhanced chemical etching of Nd: YAG for optical waveguides

Optical waveguides and waveguide lasers have optical losses and laser gain which are strongly influenced by the preparation of the surface, for example by surface scratches, stress and dislocations generated during polishing. This paper assesses the problems and the depth over which polishing damage is significant for Nd: YAG crystals. The polishing induces a dislocation density in the outer micron of the crystal which exceeds that of high grade laser crystals by ∼ 10 6. Removal of the damage layer has been aided by thermal annealing, and almost totally achieved by using ion beam amorphisation of the surface to provide a chemically reactive layer which can be rapidly etched, some 300 times faster than bulk material. The resultant new surface has a surface flatness which is comparable to, or better than the original optical surface. The method of ion beam amorphisation and chemical etching to improve surface quality should be widely applicable, as many crystals can be amorphised by ion beam damage.

Amorphization of Al 2SiO 5 polymorphs under ion beam irradiation

The three polymorphs of Al 2SiO 5 (kyanite, andalusite and sillimanite) were irradiated with 1.5 MeV Xe + using the HVEM-Tandem Facility at Argonne National Laboratory. Irradiations were completed over a temperature range of 300 to 973 K. In situ TEM, followed by HREM, was used to characterize the effects of the ion beam damage. All three Al 2SiO 5 polymorphs became amorphous after doses of 0.3 dpa at room temperature. However, the high temperature behavior of the three phases was different. The thermodynamic stabilities of the three phases were found not to have a direct relation to susceptibility to amorphization. Irradiation-induced amorphization is discussed in terms of a cascade quenching model.

Cs Ion Beam Damage of Polyvinyl chloride and Polymethyl methacrylate Studied by High Mass Resolution ToFSIMS

Cs Ion Beam Damage of Polyvinyl chloride and Polymethyl methacrylate Studied by High Mass Resolution ToFSIMS

Cs+Ion Beam Damage of Poly(vinyl chloride) and Poly(methyl methacrylate) Studied by High Mass Resolution ToF-SIMS

Changes in the SIMS spectra of poly(vinyl chloride) (PVC) and poly(methyl methacrylate) (PMMA) as a function of 8 keV Cs+dose have been studied in the range 1011–5×1013ions cm-2. In order to resolve uncertainties in previous studies (based on quadrupole SIMS and insulating samples) this work has utilized a high mass resolution ToF-SIMS instrument and films on silicon sufficiently thin to obviate the need for surface potential control (charge neutralization). The form of the damage curves has been compared with a recently introduced model of damage development based on the statistics of bond breaking. © 1997 by John Wiley & Sons, Ltd.

Ion beam studies of porphyrin adsorption on and leaching of soda lime glass

Porphyrin organic dye layers on oxidic surfaces may play a key role in the light absorption and charge separation of organic solar cells. We report a study of the adsorption characteristics of positively charged porphyrins from an aqueous solution onto soda lime glass. Advanced surface analytical techniques (RBS, ERD and XPS) have been employed to study the layer growth of the porphyrins, in order to supplement the optical measurements of the layers. A linear growth of the amount of absorbed material is found. Leaching of the material by the carbonated solution appears to result in an increasing surface area available for deposition of porphyrins in the porous top layer of the glass. The ERD measurements indicate a surplus of hydrogen in the layer, which suggest the presence of H 2O in the porous glass layer. It is shown that the MeV ion beam techniques, which are not routinely applied in studies of organic thin films, can give meaningful results if one is aware of possible ion beam damage. The coverages found with these techniques are in good agreement with coverages determined with optical measurements. They have the additional benefit of depth profiling of these layers and determining the leaching of the glass.

Ultramicrotomy of nanocrystalline materials.

The methodology and one of the first attempts to produce transmission electron microscopic (TEM) specimens of nanocrystalline metals, alloys and ceramics by ultramicrotomy are presented. Samples of the pure elements Co, Pd; alloys of Y-12 at. % Fe, Al-7 at. % Ag and W-30 at. % Ga; and ZnO ceramic, were found to section successfully to varying degrees. Advantages of sections prepared through ultramicrotomy over ion beam methods include extensive electron-transparent regions of uniform thickness and absence of ion beam damage. Typical artefacts were observed (knife marks, tearing, pull-out, shear lamellae, section curling, and anodic dissolution) but did not impede TEM analysis significantly. A potentially important effect observed was that of a texture development upon sectioning of the Co and Pd samples. It is thought that this unusual phenomenon results from the extremely fine scale of the microstructure and the purity of the Co and Pd samples, and may be enhanced by frictional heating effects and the state of the knife edge.

Ion implantation of diamond and diamond films

Abstract Ion implantation is widely employed in semiconductor device manufacture because it offers the possibility of precise control of dopant concentration and depth, and spatially selective doping is readily achievable using masking techniques. However, three major hurdles must be overcome before ion implantation doping of diamond can be practically realized. Firstly, methods must be found for the removal of the residual radiation damage without causing graphitization following the ion implantation. Secondly, the degree of electrical activation of the implanted dopants must be improved and thirdly, a suitable n-type dopant needs to be identified. Novel and innovative approaches designed to overcome these problems have recently been reported. These include pulsed laser annealing of deeply buried ion-implanted layers to achieve very high annealing temperatures while still preventing graphitization, the use of low energy ion-implantation during growth to minimize ion beam damage and maximize dopant incorporation into the diamond lattice, and multiple-step implantation/annealing cycles to improve dopant activation. In addition, fundamental studies examining the ion beam induced conductivity in diamond over a wide range of doses, ion energies and implantation temperatures have provided new insights into the nature of the damage introduced by the ion beam irradiation. In this paper, a brief review of the current status of our understanding of the interaction of ion beams with diamond is provided, with an emphasis on the new results mentioned above. In addition, since it is now clear that n-type doping of diamond films by addition of dopants to the chemical vapour deposition (CVD) growth mixture will not be as easy to achieve as first thought, a review of the work to date on the ion implantation of CVD diamond films is presented and the similarities and differences between the implantation of single crystal diamond and polycrystalline CVD films are discussed. Finally some novel and intriguing nonelectronic applications for ion beam modified diamond are presented.

Use of condensation figures to image low-energy ion beam damage of monolayer films. [Erratum to document cited in CA121:239123

Use of condensation figures to image low-energy ion beam damage of monolayer films. [Erratum to document cited in CA121:239123

Ex-situ XPS-investigation of the interface between PE-CVD SiO2 and wet chemically etched MO-CVD epitaxial layers of In0.53Ga0.47As

The As rich SiO2/In0.53Ga0.47As interface which is produced by wet chemical etching before SiO2 deposition to improve the electronic properties of the interface has been studied. SiO2-layers of about 10 to 20 nm thickness have been deposited in a plasma enhanced chemical vapour deposition (PECVD) reactor and then thinned down to about 4 to 3 nm by 1.5 keV Ar ion beam bombardment at grazing incidence (85°) in the XPS analysis chamber. The photoelectron spectra show that an additional broadening of the In and As lines due to a possible ion beam damage can be neglected in case of a qualitative interpretation of the interface spectra. Moreover, TRIM simulations of the collision cascade reveal low damage production in the SiO2/In0.53Ga0.47As interface region. Therefore such ex-situ XPS experiments allow a supervision of the interface chemistry after the fabrication process and an optimisation of the technology with regard to the etching solution and deposition conditions. The conservation or removal of the elemental arsenic and the oxidation of the semiconductor due to the SiO2 deposition are well reflected in the photoelectron spectra.

Use of Condensation Figures To Image Low-Energy Ion Beam Damage of Monolayer Films. [Erratum to document cited in CA121:239123

Use of Condensation Figures To Image Low-Energy Ion Beam Damage of Monolayer Films. [Erratum to document cited in CA121:239123

Micromechanical structures for electron- and ion-beam irradiation phenomena

Micromechanical structures are used to investigate the effects of electron- and ion-beam irradiation on silicon dioxide. The devices are simple cantilever beams (50 μm long) fabricated from different types of silicon dioxide and integrated with two parallel driving electrodes. The electrically floating silicon dioxide beams oscillate only under electron-beam irradiation with an ac voltage applied to the driving electrodes at resonance. Accumulated charge produced by electron-beam irradiation in a scanning electron microscope (SEM) produces a driving force between the cantilever beam and the driving electrode. A time-resolved SEM technique is used to determine the resonant frequencies of these micro-cantilever beams. Electron- and ion-beam damage is measured by detecting the shift in the resonant frequency as a function of the irradiation time (electron-beam dose or sputtering time). Experimental results show that the resonant frequency of the silicon dioxide cantilever beam increases under electron-beam irradiation; this frequency rise indicates that material hardening or mass loss or both occur when the cantilever is subjected to electron-beam irradiation. We also observed differences in the rate of change of the frequency shift between thermally grown silicon dioxide films and plasma enhanced chemical vapor deposition silicon dioxide films. Under argon sputtering, the resonant frequency of the silicon dioxide cantilever beam decreases due to the change in the dimensions and mass of the cantilever beam caused by sputtering.

Use of Condensation Figures To Image Low-Energy Ion Beam Damage of Monolayer Films

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUse of Condensation Figures To Image Low-Energy Ion Beam Damage of Monolayer FilmsThomas E. Kane, Vincent J. Angelico, and Vicki H. WysockiCite this: Anal. Chem. 1994, 66, 21, 3733–3736Publication Date (Print):November 1, 1994Publication History Published online1 May 2002Published inissue 1 November 1994https://doi.org/10.1021/ac00093a031RIGHTS & PERMISSIONSArticle Views92Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts Get e-Alerts

An AES study of intrinsic and ion-induced structure in the SiO 2-Si system

Detailed changes in the Si LVV N( E) spectrum across the SiO 2-Si system are evaluated in relation with ion beam damage (argon ions of energy 90–500 eV). Typical samples are: thin or thick SiO 2 films, the depth-profiled SiO 2/Si interface and SiO x compounds. The width of the main oxide peak and the shape of the elemental Si signal are useful indicators of modifications affecting the oxide: structural distortion and Si clustering induced by the ion beam, and structural distortion due to the proximity of the Si phase. These effects depend critically on the oxide thickness in the range 0–2.0 nm.

Atomic force microscopy studies of layer silicate minerals

The surfaces of silicate minerals are important in controlling a number of geochemical phenomena from chemical weathering, to the transport of pollutants in solution. The atomic force microscope (AFM) has proven invaluable for obtaining atomic resolution images of the surface topology and structure of a wide variety of minerals. While the physical basis for the sample—tip interactions responsible for the images remains poorly understood, comparison of AFM images with the calculated bulk mineral structures, provides clear evidence that the AFM is truely capable of resolving structural features on the atomic scale. The phyllosilicate or layered silicate minerals are particularly suited to study by atomic force microscopy because of their perfect {001} cleavage, wide range of structure types and variety of surface properties. Atomic resolution images have been obtained on lizardite, chlorite, apophyllite and muscovite. The AFM resolves the Ångstrom-scale surface structure of these minerals and is able to clearly elucidate the different structural layers. These studies have been able to observe surface relaxation effects on the surface of chlorite, as well as the progressive amorphization (through ion beam damage) of the muscovite surface. Further, studies in solution are able to image the equilibrated near surface structure providing fresh insight into the nature of the mineral—water interface.