bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ion beam analysis of single crystal CVD diamond
Authors: Manfredotti Claudio , Lo GIudice Alessandro , Medunic Stiepko , Jaksic Milko , Colombo Elisabetta 
Published: April 2011

AbstractIBIC ( Ion Beam Induced Charge ) represents a powerful method to investigate the homogeneity of the response of semiconductor nuclear detectors from the point of view of charge collection efficiency ( cce ) with a spatial resolution of few microns. Polycrystalline materials like CVD diamond displayed in the past non-uniform cce maps, in which it was easy to notice the appearance of single grains. Moreover, the presence of traps in the defective regions around the grain boundaries caused strong polarization effects which in practice impeded in many cases to get reasonable cce maps. With the availability of new homoepitaxially grown CVD diamond samples the situation is now very much improved : maps are very uniform and the non-homogeneous broadening of peaks with the consequent worsening of energy resolution is extremely reduced.In this paper, both proton and alpha microbeams of energies 3 and 4.5 MeV were used for the investigation of single crystal CVD homoepitaxial diamond, with a beam diameter spot of about 1.2 mm over scanned areas of more than 1 mm2, sampled in regions of interest from 450 um × 450 um down to 150 um × 150 um and below. The good spatial homogeneity together with a cce value of about 50 % made it possible to reach energy resolutions of 1.3 % FWHM, including a not negligible electrical noise. These values compare quite well with Si performances, which in the same conditions reached 0.85% FWHM. The stability and reproducibility of the detector was very good without any preliminary priming and polarization effects were reduced to a minimum. The detector was pushed in some cases up to 700 cps with apparently no cce losses and with only a slight worsening of energy resolution.
High Energy Focused Ion Beam Nanoprobes: Design and Applications
Authors: Glass Gary A. , Rout Bibhudutta , Dymnikov Alexander D. , Eschenazi Elia V. , Greco Richard , Zachry Daniel P. 
Published: April 2011

AbstractAn overview of the present state of high energy focused ion beam (HEFIB) system technology, nanoprobe system design and specific ion beam writing applications will be presented. In particular, the combination of P-beam, heavy-ion writing and ion implantation to produce microstructures in resists and silicon will be demonstrated.Heretofore, the development of HEFIB technology worldwide has progressed through a series of developments at independent research facilities, each having relatively narrow and mostly isolated, research purposes. However, a complete, versatile HEFIB nanoprobe system capable of both analysis and modification will require the combination of several component systems, each with specialized technology, and significant advances in the design of a complete system can only be expected from an effort that includes a coordinated development of the component parts.
Positron Annihilation Investigation in Ion-implanted Yttria-stabilized Zirconia
Authors: Grynszpan Robert , Brauer G. , Anwand W. 
Published: April 2011

AbstractImplantation with a variety of sub-MeV ions (He, Ar, Xe, O, and I) were performed on cubic single crystals of yttria-stabilized zirconia in order to assess the capability of such material to withstand high fluences as a confinement matrix for nuclear waste. In this work, we confronted the results of both Doppler Broadening using slow positron implantation spectroscopy (DB-SPIS) and the Rutherford Backscattering/Channeling spectroscopy (RBS-C) which are sensitive to lattice defects almost opposite in nature. In spite of their difference in defect specific sensitivity, and except for a precursory damage production stage almost exclusively exhibited by SPIS for very low doses (< 0.1 dpa), either techniques show a similar fluence dependence, which exhibits 3 stages starting respectively around 0.1, 2 and 3 dpa, regardless of the damaging ion. However, owing to the stage I plateau displayed in the variation of the DB-SPIS lineshape parameter, we were able to estimate an ion-mass dependence of the critical size of open-volume defects reached before the production of new predominant defects.
Formation and characterization of swelled nano-porous structures on ion-irradiated Ge surfaces
Authors: Yanagisawa Junichi , Ogushi Keiji , Takarabe Kentaro , Gamo Kenji , Akasaka Yoichi 
Published: April 2011

AbstractSingle crystal germanium (Ge) surfaces were irradiated with 100 keV Ga ions at room temperature at doses up to 3×1017 cm-2 and were observed by a scanning electron microscope (SEM) and an atomic force microscope (AFM). It is found that the Ga-irradiated regions swelled and nano-porous structures were formed on the surface after the Ga irradiation up to a dose of about 2×1017 cm-2, but the region was etched by the Ga irradiation for larger doses. The atomic composition of the swelled and etched surfaces was investigated by an Auger electron spectroscopy (AES), but no Ga signal was observed, indicating that the precipitation of Ga did not influence on these characteristics of the Ga-irradiated Ge surfaces. To investigate the water resistance of such nano-porous structures, the sample was dipped in water up to 10 hours, and the surface was observed using SEM and AFM. It is found that the swelled structures were maintained, but the etched region formed by larger-dose irradiation was partially peeled off. This indicates that the nano-porous structures can be used under water environments as a functional surface, such as filters, and deep etching can be performed by larger dose irradiations and dipping the sample in water.
Fabrication of patterned domains with graphitic clusters in amorphous carbon using a combination of ion implantation and electron irradiation techniques
Authors: Iwamura Eiji , Aizawa Tatsuhiko 
Published: April 2011

AbstractFabrication of domains containing graphitic structures in amorphous carbon (a-C) films was demonstrated. Amorphous carbon thin films with 200 nm thickness were deposited on Si substrates by ion-beam sputtering. Iron atoms in a range from 4×1013 to 3.7×1016 cm-2 were doped to the a-C films by an ion implantation technique through a nickel mask with a grid of square windows of 500×500 μm and a net of 50 μm in width as a template. After removing the metal mask, the partly Fe-containing a-C films were exposed to a low-energy electron shower. In the regions where Fe atoms were implanted, Fe were crystallized and preferably diffused toward the film surface leaving graphitic structures more than 10 nm in size in the interior of the amorphous carbon films. On the other hand, the masked regions, where Fe atoms were not implanted, remained amorphous. The results suggest that regions, which consist of amorphous domains and graphitic domains, can be intentionally arranged in a-C thin films.
SIMS Depth Profiling Free of Martix Effects
Authors: Huber Peter , Karl Helmut , Stritzker Bernd 
Published: April 2011

AbstractWe present a method of determining elemental depth profiles with secondary ion mass spectrometry (SIMS) corrected by all non-linearities between the SIMS countrate and the elemental concentration caused by chemical matrix effects, resulting in an absolute concentration depth profile. The key to this method is a low dose ion implantation step of corresponding reference isotopes prior to SIMS depth profiling. Spectra evaluation is performed on the basis of a selfconsistent evaluation in which the depth dependent influence of the matrix is determined. The technique is demonstrated for sequentially high dose ion implanted Cd and Se in SiO2.
Characterization of Plasma Immersion Deposited Multilayer Coatings by Ion Beam Techniques Combined with Energy Filtered Transmission Electron Microscopy
Authors: Schwarz Florian , Lindner Joerg K. N. , Häeberlen Maik , Thorwarth Goetz , Hammerl Claus , Assmann Walter , Kuhn Marcus , Stritzker Bernd 
Published: April 2011

AbstractMultilayered and nanostructured coatings of amorphous carbon (DLC), silicon composite multilayers and nanocluster containing films today have great potential for applications as hard coatings, wear reduction layers and as diffusion barriers in biomaterials. Plasma immersion ion implantation and deposition (PIII&D) is a powerful technique to synthesize such films. The quantitative nanoscale analysis of the elemental distribution in such multielemental films and thin film stacks however is demanding.In this paper it is shown how the high spatial resolution capabilities of energy filtered trans-mission electron microscopy (EFTEM) chemical analysis can be combined with accurate and standard-less concentration determination of ion beam analysis (IBA) techniques like Rutherford Backscattering Spectroscopy (RBS) and Elastic Recoil Detection Analysis (ERDA) to achieve absolute and accurate multielement concentration profiles in complicated nanomaterials.
Deposition of ITO Film on Ion Beam Treated Polymers
Authors: Hsiao Shih Hsiu , Yamaguchi Tetsuro , Tanaka Yoshikazu , Ide-Ektessabi Ari 
Published: April 2011

AbstractIndium oxide doped with tin oxide, ITO, is extensively used to fabricate transparent conductive coatings. ITO thin film on flexible substrates has been used in applications including touch panel contacts, electrodes for LCD and Plasma displays. ITO thin film can be deposited onto polymer substrates using electron-beam evaporation. Surface modification of polymer substrate improves its superficial properties, adhesion in particular, to meet specific requirements while retaining the good mechanical properties of the substrates. In this study, a system consists of a linear ion beam and an electron beam which have been developed in vacuum. The linear ion beam treats the polymer surface while simultaneously the ITO thin film is deposited onto the surface using electron-beam evaporation. We demonstrated that polymer surface treated with the ion beam has been improved. Moreover, the linear ion beam source provides good uniformity of surface treatment and is very suitable for production-scale processes. An integrated electron-beam evaporation and linear ion beam system significantly increases the chemical compatibility of a polymer surface to an over-layer.
Low Temperature Annealing Effects on Magnetron Sputtered Ni(V)/Al Reactive Coatings
Authors: Blickley Matthew P. , Soroka Nicholas A. , Demaree John Derek , Hirvonen James K. , Dehmer Peter G. 
Published: April 2011

AbstractReactive nanofoil coatings of magnetron-sputtered aluminum and nickel/vanadium bilayers were characterized for reliable debonding of segmented carbon composite or metallic structures to be used in future Army applications. We determined the initiation energies of multilayer stacks by discharging an electric spark from a fixed capacitor bank and varying DC voltage before and after low temperature annealing, which resulted in varying amounts of interfacial interdiffusion observable by Rutherford backscattering spectrometry (RBS). The propagation velocity of the reaction was also measured using high speed video photography. Significant increases in initiation energy and decreasing propagation velocities were observed with increasing anneal times and temperatures, in agreement with the RBS results and existing literature discussion of reaction mechanisms. Initiation sensitivity and propagation velocity were both impacted by varying the stoichiometric ratio of Al and Ni/V, and the propagation rate was also affected by the nature of the substrate. These results allow for the optimization of both reliable initiation and long term, low temperature storage stability of the final reactive coatings for debonding applications.
Time-resolved Photoconductivity as a Probe of Carrier Transport in Microcrystalline Silicon
Authors: Reynolds Steve 
Published: April 2011

AbstractThe use of transient photoconductivity techniques in the investigation of carrier transport in microcrystalline silicon is described. Results are presented which highlight variations in transport parameters such as carrier mobility and density of states with structure composition. Hole mobility is significantly enhanced by crystalline content in the film of 10% or less. The density of states inferred from transport measurements parallel to and at right angles to the direction of film growth differ somewhat, suggesting that transport may be anisotropic.
Characterization of the Evolution in Metastable Defects Created by Recombination of Carriers Generated by Photo-generation and Injection in p-i-n a-Si:H Solar Cells
Authors: Deng Jingdong , Rross Benjamin , Albert Mathew , Collins Robert , Wronski Christopher 
Published: April 2011

AbstractThe creation of metastable defects in the bulk of the intrinsic layers of a-Si:H p-i-n solar cells by recombination of photo-generated carriers as well as those injected under far forward bias has been investigated. The evolutions in the defects, created with volume-absorbed red light at open circuit voltage and constant far forward bias currents, were characterized with the Shockley-Reed-Hall recombination obtained from the dark currents under low forward bias voltages. This allowed the kinetics to be studied at different temperatures in the absence of isothermal annealing. It is found that the form of the kinetics obtained with the two methods are the same and a detailed study was carried out with currents from 1 to 100mA/cm2 with carrier injection during which the electron and hole concentrations remain essentially constant. This kinetics is similar to that reported for thin film results exhibiting stretched exponential behavior with a t1/3 relation over a limited regime before the onset of saturation. By separating the contributions of the metastable defects from the intrinsic defects, their evolution is found to have a t1/2 dependence over the entire range prior to the onset of saturation. Since these kinetics also exhibit an (intensity)2t dependence they point to a rate equation for the creation of metastable defects, Nms, dNms / dt ~ (intensity)2 / Nms, which is suggestive of new creation mechanisms for SWE defects.
Properties of Nanocrystalline 3C-SiC:H and SiC:Ge:H Films Deposited at Low Substrate Temperatures
Authors: Miyajima Shinsuke , Yamada Akira , Konagai Makoto 
Published: April 2011

AbstractWe have investigated properties of nanocrystalline hydrogenated cubic silicon carbide (nc-3C-SiC:H) and silicon carbide: germanium alloy (nc-SiC:Ge:H) films deposited by hot-wire chemical vapor deposition (HWCVD) at low temperatures of about 300°C. we found that the density of charged defects was strongly influenced by grain size of the films. In-situ doping into nc-3C-SiC:H films was also carried out. N-type nc-3C-SiC:H films were successfully deposited by using phosphine (PH3) and hexamethyldisilazane (HMDS) as dopants. We found that HMDS is an effective n-type dopant for low temperature deposition of nc-3C-SiC:H films by HWCVD. For the deposition of p-type nc-3C-SiC:H with trimethylaluminum (TMA), it was found that the substrate temperature of above 300°C is required to activate the acceptors. We added dimethylgermane (DMG) into mixture of MMS and H2 to prepare nc-SiC:Ge:H films. The nc-SiC:Ge:H films with Ge mole fraction of 1.9% were successfully deposited.
Interface Study Of Nanocrystalline Silicon and Crystalline Silicon Using Microwave Photoconductivity Decay
Authors: Farrokh Baroughi Mahdi , Sivoththaman Siva 
Published: April 2011

AbstractThis paper presents a measurement technique for studying of the interface between a nanocrystalline silicon (nc-Si) film and a crystalline silicon (c-Si) substrate using microwave photoconductivity decay (MWPCD). The nc-Si films were deposited using plasma enhanced chemical vapor deposition of highly hydrogen-diluted silane. The films were deposited on both sides of the high purity float-zone (FZ) Si wafers. The high resolution transmission electron microscope (HRTEM) analysis of the interface and the characterization of the effective excess carrier lifetime of the samples using MWPCD revealed the following results: (i) The crystallinity of the deposited nc-Si films is very high. The nc-Si film follows the crystal orientation of the substrate such that not a well-defined boundary between nc-Si film and the c-Si substrate is observed. (ii) A surface recombination velocity of less than 10 cm/s was measured for the interface region of the nc-Si/c-Si junctions. (iii) A small discontinuity in the band-energy diagram of the interface region was observed.
Microstructure Characterization of Amorphous Silicon-Nitride Films by Effusion Measurements
Authors: Beyer Wolfhard , Dekkers H.F.W. 
Published: April 2011

AbstractThe microstructure of a-Si:N:H films, which are applied as antireflection coating and for defect passivation in multicrystalline silicon (mc-Si) solar cells, was studied by gas effusion experiments. The results show for as-deposited material of low substrate temperatures (TS = 200 – 300°C) a predominant diffusion of molecular hydrogen for temperatures up to 800°C in agreement with the presence of interconnected openings (voids). At higher substrate temperatures, the material has a more compact structure and atomic hydrogen is the dominant diffusing species in the accessible temperature range. Annealing effects were also studied. The results are consistent with the concept that atomic hydrogen released from the a-Si:N:H coating serves for defect passivation in μc-Si solar cells.
Effect of Hydrogen Dilution on Structure and Electronic Properties of Ge:H and GeYSi1-Y Films Deposited by Low Frequency Plasma
Authors: Kosarev Andrey , Sanchez L. , Torres A. , Felter T. , Ilinskii A. , Kudrjavtsev Y. , Asomoza R. 
Published: April 2011

AbstractWe report on a systematical study of growth rate, surface morphology, hydrogen and oxygen incorporation, optical and electrical properties in Ge:H and GeYSi1-Y:H, Y> 0.85 films, deposited in a capacitive reactor by low frequency PE CVD. Silane and germane were used as feed gases diluted by hydrogen. Hydrogen dilution characterized by R= QH2/[QSiH4+QGeH4], where QH2, QSiH4, and QGeH4 are gas flows of hydrogen, silane and germane, respectively. The flow was varied in the range of R=20 to 80. Composition of the films was characterized by SIMS profiling. We did not observed a significant change of the deposition rate Vd in GeYSi1-Y:H films in all the range of R, while for Ge:H films Vd was significantly reduced after R=50. AFM characterization of the surface morphology demonstrated that at R=50 average height <H>(R) reached maximum in both Ge:H and GeYSi1-Y:H films, while average diameter <D>(R) had a minimum in GeYSi1-Y:H films and maximum in Ge:H films. Both Ge:H and GeYSi1-Y:H films demonstrated change of E04 in the studied range of R, and a minimum clearly appeared in &#61508;E at R=50-60 suggesting significant reduction in weak bonds of these films. The activation energy of conductivity Ea slightly increases with R in Ge:H films and shows no definitive trend in GeYSi1-Y:H: films. Both FTIR and SIMS data show a general trend of reducing hydrogen and oxygen content with R. These two types of films showed different behavior and correlations between surface morphology and optical and electrical properties.
Detection of SiH3 radicals and cluster formation in a highly H2 diluted SiH4 VHF plasma by means of time resolved cavity ring down spectroscopy
Authors: Nagai Takehiko , Smets Arno H. M. , Kondo Michio 
Published: April 2011

AbstractThe spatial distribution of the SiH3 radicals between the electrodes of a hydrogen diluted silane VHF plasma under thin film hydrogenated microcrystalline silicon (μc-Si:H) growth conditions has been measured using the time resolved cavity ringdown (τ-CRD) absorption spectroscopy technique. The μc-Si:H growth rate is estimated from the measured spatial SiH3 profiles using a simple model based upon diffusion controlled flux of SiH3 radicals to the electrode surface, where the SiH3 can react with the film surface. The calculated value of μc-Si:H growth rate roughly agrees with the value of the experimentally determined growth rate. This agreement implies that the SiH3 radical is the main growth contributor to the μc-Si:H growth. Furthermore, the τ-CRD reveals the growth kinetics of the clusters in the plasma by light scattering at these clusters on time scales of 1 s after the plasma ignition.
Thermally-Stimulated Currents in Thin-Film Semiconductors: Analysis and Modelling
Authors: Main Charles , Souffi Nacera , Reynolds Steve , Aneva Zdravka , Brüggemann Rudi , Rose Mervyn 
Published: April 2011

AbstractThis paper investigates the robustness of the thermally stimulated current technique as a method to determine the density of states distribution in thin film semiconductors under a wide range of conditions. Numerical simulation is used to solve the non-linear time-dependent rate equations for free and trapped charge in systems with continuous and structured DOS profiles. We explore the derivation of energy and density scales from temperature and conductivity data. We examine for these systems the limits of the method's apparent immunity to varying conditions of strong and weak retrapping, and investigate the corrections required for variations in carrier lifetime with temperature.
Pulsed Laser Deposition of Boron Doped Si70Ge30
Authors: Sedky Sherif , ElDeftar Ibrahim , Mortagy Omar 
Published: April 2011

AbstractThe main objective of this work is to investigate the possibility of combining pulsed laser deposition (PLD) and pulsed laser annealing to realize p-type Si1-xGex thin films suitable for post-processing MEMS on top of standard pre-fabricated driving electronics. The main advantage of this approach is that the substrate is kept at a CMOS backend compatible temperature throughout the deposition and thus the MEMS integration process will have no thermal impact on the underlying electronics. In addition, it is demonstrated that PLD Si1-xGex has good adhesion to SiO2 and accordingly there is no need for a silicon nucleation which is the case for LPCVD and PECVD. Furthermore, this technique is much more economical than CVD as it does don't imply using expensive gas precursors such as germane and silane.
Growth and Electronic Properties of Nanocrystalline Si
Authors: Dalal Vikram , Muthukrishnan Kamal , Saripalli Satya , Stieler Dan , Noack Max 
Published: April 2011

AbstractNanocrystalline Silicon is an important electronic materials for solar cells, for display devices and for sensors. In this paper, we discuss the influence of ions on the growth and properties of thenanocrystalline Si:H material. Using a unique growth geometry, combination of hot wire and ECR plasma growth, we show that low energy ion bombrdment is beneficial for growing high quality materials. Ion bombardment by H is shown to etch the films during growth and also promote crystallinity. The results on film growth are compared with simulations of growth using the SRIM program. The electronic properties measured include mobilities of both electrons and holes in device-type structures, carrier lifetimes, diffusion lengths, defect densities and capture cross-sections for holes. Electron mobility is found to increase with grain size, with a minimum mobility being in the range of 1 cm2/V-s. The hole mobility is also in this range, and three different methods of measuring it give approximately the same value. The capture cross-section for holes is of the order of 1-2 × 10-16 cm2. The lifetime of carriers is found to depend inversely on the defect density, implying that the recombination is trap controlled.