bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative Materials Analysis by Laser Microprobe Mass Analysis
Authors: Odom Robert W. , Hitzman Charles J. , Schueler Bruno W. 
Published: March 2011

AbstractThe laser microprobe mass analysis (LMMA) technique currently finds extensive application in the qualitative microanalysis of a wide range of materials. These microanalytical applications include the analysis of polymeric materials [1], semiconductors [2] and particulate samples [3]. These qualitative analyses have repeatedly demonstrated the analytical ability of this technique for producing rapid, elemental, isotopic and, in some cases, molecular characterization of these types of materials. The development of quantitative or semi-quantitative analytical methodologies is the goal of any analytical technique and rather extensive investigation of the quantitative capabilities of the laser microprobe technique have been pursued since the initial development of this technique. These investigations have centered on developing appropriate microanalytical standards [4], characterizing the pertinent physical and chemical processes occurring during high power laser irradiation of materials [5] and modeling the nature and extent of the ionization produced with physically reasonable models [6, 7]. To date, these quantitative studies have generally provided good analytical methods and results and, although the number of quantitative analyses of materials systems have been rather limited, the results do provide sufficient encouragement to pursue further quantitative studies with this technique. In this paper, we discuss the results obtained in a laser microprobe analysis of phosphosilicate glass (PSG) standards in which the quantitative capabilities of the technique for the determination of the phosphorous content of PSG glasses were evaluated. The results of this analysis were compared to those produced from a secondary ion mass spectrometry (SIMS) analysis of these PSG standards. We have also evaluated the in-depth profiling capability of the laser microprobe technique and demonstrate this capability with a depth profile of a 11B implant into Si. Finally, we present preliminary data obtained from a new modification to the basic laser microprobe technique in which the conventional laser system is employed to ablate the sample material and a second laser pulse ionizes the neutral-components in the vapor plume produced by the ablation laser. This two laser configuration of the laser microprobe promises to improve the sensitivity and reproducibility of this microanalysis technique.
Present and Emerging Techniques for Materials Microanalysis
Authors: Helms C. R. 
Published: March 2011

AbstractAlthough classical materials characterization methods have existed for many years, modern microanalytical techniques had their start just over twenty years ago. In this paper, I will discuss some of the common techniques available today including AES, XPS, or ESCA, RBS, SIMS, and EDAX. A comparison of the key capabilities and limitations will be given including sensitivity, spatial resolution, quantitative analysis, nondestructive testing, chemical state determination, and analysis speed. It is clear that the reason each of these techniques still exists as commercial instrumentation is that each provides a unique set of capabilities, but also a unique set of limitations. To become viable in the materials analysis arena, a new technique must offer a significant extension of the capabilities already available but not at the cost of too severe a set of limitations. Examples would be the development of tools that offer both high sensitivity with accurate quantitative analysis, or good spatial resolution with high sensitivity, or minimal damage but good spatial resolution, etc. A number of papers in this volume will describe the details of these emerging technologies which provide advances in these areas; and I will attempt here to put a number of these new developments in perspective with regard to the more commonplace techniques available.
The Depth Resolution of Dynamic Sims: Experiments and Calculations
Authors: Giles M. D. , Hoyt J. L. , Gibbons J. F. 
Published: March 2011

AbstractThis study is concerned with the fundamental limitations imposed by cascade mixing and recoil implantation on the depth resolution of secondary ion mass spectrometry (SIMS), and the effects of these limitations on the determination of impurity profiles in semiconductors.We present experimental results of measurements on atomically, or near atomically abrupt impurity profiles in Si using magnetic sector (Cameca) and quadrupole (Atomica) SIMS machines. The analysis conditions and samples have been chosen to minimize instrument (crater wall resputtering) and surface (equilibration time) effects. Under such conditions the leading edge of an abrupt signal is smeared to a complimentary error function, while the trailing edge exhibits an exponential decay reminiscent of recoil implantation profiles.Modifications of the Boltzmann Transport Equation (BTE) approach to ion implantation in multilayer targets will be shown to provide a first principles calculation of such SIMS knock-on phenomena, which is in good agreement with the empirical results.
Using Hyperfine Interaction for the Structural Characterization of Amorphous Silicon
Authors: Stutzmann Martin , Biegelsen David K. 
Published: March 2011

AbstractThe hyperfine interaction between electronic and nuclear spins in hydrogenated amorphous silicon has been observed for the various paramagnetic defects in this material by electron spin resonance (ESR) and electron nuclear double resonance (ENDOR). The large hyperfine interaction between dangling bonds and 29Si as well as between donor electrons and 31p or 75 As nuclei can be resolved in ESR and provides direct information about the structure of the underlying electronic states. The smaller dipolar coupling of all paramagnetic states to more distant nuclei leads to an ENDOR response near the free nuclear resonance frequencies, which can be used to study the coupling of the electronic and nuclear spin system to the lattice phonons and to each other.
Formation of Au-Si Metastable Phases by Ion Mixing
Authors: Liu Bai-Xin , Wieluniski Leszek S. , MÄenpÄÄ Martti , Nicolet Marc-A. , Lau S. S. 
Published: March 2011

ABSTRACTAmorphous and three metastable crystalline phases have been formed in the Au-Si system by 300 keV Xe ion mixing using multilayered samples with average compositions of Au2Si8, AuSi, and Au7 Si3. Generally speaking, during the different stages of irradiation at liquid nitrogen temperature (LNT) or room temperature (R.T.), metastable crystalline phases are formed initially, and eventually an amorphous structure is obtained. Thermal decomposition of amorphous alloys yield different metastable crystalline phases. Some of the metastable crystalline phases can be formed directly from multilayered samples by steady-state thermal annealing. The formation mechanisms of metastable phases are discussed in terms of the processes involved in ion mixing and thermal annealing.
Atomic and Electronic Structure of Amorphous Alloys
Authors: Johnson William L. 
Published: March 2011

ABSTRACTAmorphous metallic alloys can be synthesized by many techniques including melt quenching, vapor quenching, electrodeposition, and irradiation of crystalline alloys by neutrons or by ions. Certain alloys are prone to glass formation and can be readily made amorphous by all of these methods. In this article, a survey of experimental data on the atomic and electronic structure of such good glass forming alloys is presented. On the basis of this data, it is argued that good glass forming alloys tend to have in common several underlying microscopic features. The article concludes with some general remarks on the relationship of these common features to glass formation.
Non Equilibrium Structures in Ion Implanted B2 Type Fe-Al and NiTi Ordered Alloys.
Authors: Moine P. , Riviere J. P. , Junqua N. , Delafond J. 
Published: March 2011

ABSTRACTTwo b.c.c. ordered alloys Fe-40 at % Al and Ni-Ti have been investigated by transmission electron microscopy after self ion implantation Al+ and Ni+ respectively. Partially disordered regions are observed in the Fe-40 at % Al. On the contrary, in the Ni-Ti alloy, complete transformation to the amorphous state occured. During post implantation annealings, the precipitation of a new f.c.c. phase is observed in the Fe-40 at % Al ordered alloy, in the amorphous Ni-Ti the recrystallization occurs in a temperature range 400 – 550°C; the new phase has a structure either martensite type or B2 type with modulatiens.
Friction and Wear of Stainless Steels Implanted with Ti and C
Authors: Yost F. G. , Pope L. E. , Follstaedt D. M. , Knapp J. A. , Picraux S. T. 
Published: March 2011

ABSTRACTFriction and wear tests were completed on Fe, and stainless steels of the type 304, 15–5 PH, Nitronic 60 and 440C implanted with Ti and C. Samples were mechanically polished prior to ion implantation to fluences of 2 × 1017 Ti/cm2 (90–180 keV) and 2 × 1017 C/cm2 (30 keV); the implantation profiles of the two elements overlapped to 0.1 μm. Light load wear conditions with no lubrication were evaluated in a pin-on-disc configuration. Ion implantation significantly reduced the friction coefficient by up to 75% and decreased the maximum wear depth by up to 95%, but both effects were material and load dependent. Only stainless steel 304 had both friction and wear reduced by implantation for all loads examined. Fine-scale parallel grooves were present in the wear track for light loads, but this wear pattern was transformed to a galled structure at high loads. A correlation existed between decreased friction, reduced wear, the wear track morphology and Ti in the wear track.
Structure and Properties of Silicon Carbide Implanted With Chromium
Authors: Mchargue C. J. , Williams J. M. 
Published: March 2011

ABSTRACTThe effects of implanting chromium at fluences of up to 2.6 × 1016/cm2 on the structure and properties of single- and polycrystalline samples of SiC were studied. The material turned amorphous due to the implantation. The hardness decreased by as much as 25% and the fracture toughness increased by approximately 10% due to the implantation. The most interesting finding was that the material swells by as much as 30% upon implantation of some 2 × 1016 Cr-ions/cm2.
Thermal Stability of Metastable Phases Produced by Laser Treatment of Aluminium Implanted With Chromium and Molybdenum
Authors: Battaglin G. , Carnera A. , Della Mea G. , Mazzoldi P. , Jain Animesh K. , Kulkarni V.N. , Sood D.K. 
Published: March 2011

ABSTRACTWe present a first He ion channeling study on thermal stability (under isochronal vacuum furnace annealing at 300-650°C) of metastable solid solution phases produced by pulsed ruby laser treatment of Al implanted with Cr and Mo. Laser treated Cr exhibits strong redistribution inferred to be due to intermetallic phase precipitation which appears to be enhanced by quenched-in defects. In contrast, laser treated Mo shows no redistribution but only a loss of substitutionality. Instead of annealing, thermal treatment produces an increase in host dechanneling yield for all laser treated samples. Detailed comparison with thermal recovery of as implanted phases demonstrates the key role played by quenched-in defects.
Raman Spectra of Ion Implanted Graphite
Authors: Elman B.S. , Mazurek H. , Dresselhaus M.S. , Dresselhaus G. 
Published: March 2011

ABSTRACTRaman spectroscopy is used in a variety of ways to monitor different aspects of the lattice damage caused by ion implantation into graphite. Particular attention is given to the use of Raman spectroscopy to monitor the restoration of lattice order by the annealing process, which depends critically on the annealing temperature and on the extent of the original lattice damage. At low fluences the highly disordered region is localized in the implanted region and relatively low annealing temperatures are required, compared with the implantation at high fluences where the highly disordered region extends all the way to the surface. At high fluences, annealing temperatures comparable to those required for the graphitization of carbons are necessary to fully restore lattice order.
Ion Mixing During Film Deposition: Growth of Metastable Semiconducting and Metallic Alloys
Authors: Cadien K.C. , Ray M.A. , Shin S.M. , Rigsbee J.M. , Barnett S.A. , Greene J.E. 
Published: March 2011

ABSTRACTEpitaxial metastable (GaSb)1−Gex alloys with compositions across the pseudobinary phase diagram have been grown on (100) GaAs substrates by multitarget rf sputtering. An essential feature allowing the growth of these unique materials was low energy ion bombardment of the growing film during deposition to promote collisional mixing and enhance adatom diffusion. Annealing experiments indicated that the metastable films exhibit good high temperature stability. While the free energy difference between the single phase metastable and two phase equilibrium states is only ∼ 20 meV/atom, the activation barrier for the transformation is ∼ 3 eV. All films were ptype with room temperature carrier concentrations and mobilities between 1016 and 1019 cm−3 and 10 and 720 cm2/V∼sec, respectively, depending on film composition. Collisional mixing due to low energy ion bombardment of the growing film was also found to affect both the transformation rate kinetics as well as the reaction path during subsequent annealing of amorphous GaSb/Ge mixtures deposited on glass at 60°C. Finally, some initial results on the deposition of metastable fcc Cu/Cr alloys are presented.
Influence of Preparation Conditions on Charge Carrier Dynamics In a-Si:H Determined By An In-Siju Technique
Authors: Werner A. , Kunst M. 
Published: March 2011

ABSTRACTContactless photoconductivity measurements with the time-resolved microwave conductivity technique have been performed during the growth of hydrogenated amorphous silicon films. it has been shown that low substrate temperature and thin films lead to a larger electron decay rate and to an increased infrared absorption compared with high quality films. Addition of H2S to SiH4 during the glow discharge process leads to a worse fi1m quality which can be detected in-situ.
Interpretation of The a-Si:H DLTS and ICTS Experimental Data
Authors: Han Ru-Qi , Ngai K. L. , Ruvalds J. 
Published: March 2011

ABSTRACTThe isothermal capacitance transient spectroscopy (ICTS) data of a- Si:H is consistently analyzed in terms of a relaxation function with a fractional exponential time decay of the form φ(t)=exp[-(t/τ*)λ] with λ≅0.8. The anomalous variation of the effective relaxation time τ* (and hence that of the attempt-to-escape frequency ν* and the capture cross section σ* observed by Okushi and coworkers) with energy and temperature is shown to follow an additional prediction of the time dependent relaxation rate coupling model developed by Ngai and coworkers for relaxations in many complex systems. A modified energy scale is extended from the ICTS analysis which brings its electronic density of states structure in closer agreement with results obtained by DLTS experiments.
Deposition Kinetics and Structural Control of Highly Photosensitive A-SiGe:H Alloys
Authors: Tanaka Kazunobu , Matsuda Akihisa 
Published: March 2011

ABSTRACTFirstly, on the basis of the classical model on the surface process of adsorbed species, a guiding principle is proposed for the preparation of high-quality a-SiGe:H alloys via plasma-CVD technique. Secondly, a- SiGe:H alloys were prepared by the rf-discharge technique with three intentional modifications; (A) from SiH4/GeH4 using a diode reactor (conventional method), (B) from SiH4/GeH4 using a triode reactor (triode method), (C) from SiH4/GeH4/H2 mixture using the diode reactor (H2-dilution method). Finally, growth mechanism is discussed in terms of the selection of long-lifetime radicals in a plasma and the H-coverage factor of the growing surface, providing us a clue to materials design.
Infrared Spectroscopy of Deuterated a-Si, Ge:D, F Alloys Prepared by DC Glow Discharge Deposition
Authors: Okada Y. , Slobodin D. , Chou S. F. , Schwarz R. , Wagner S. 
Published: March 2011

ABSTRACTDeuterated and fluorinated amorphous silicon-germanium alloys, a-Si, Ge:D, F, were studied by Fourier transform infrared (IR) spectroscopy. No Ge.-F modes are observed. The intensity of the Si-F and Si-F2 modes increases with Ge concentration. So does thae intensity of SiF4 which is trapped as isolated molecules. No DF (IR) or F2 (Raman) is observed. The IR spectra of alloys annealed at 300, 400, 500 and 600° C show that the fluorine in the Si-F and Si-F2 groups and in the SiF4 molecules is in thermochemical equilibrium.
Surface Reactions in Discharge and Cvd Deposition of Silane
Authors: Gallagher Alan 
Published: March 2011

ABSTRACTGlow discharge deposition of hydrogenated amorphous silicon films involves; (A) the electron collisions which produce the reactive species, (B) the gas reactions these species undergo while diffusing or drifting to the surfaces, and (C) the surface reactions involved in film growth and gas processing. I will first describe our knowledge of the electron and gas reactions in these discharges, then of the surface reactions, and finally I will offer some conjectures regarding the influence of these different surface reactions and bombardments upon film properties.
Glow Discharge Produce Amorphous Sic:H Thin Films
Authors: Tran N. T. , Olsen D. J. , Patel R. I. , Epstein K. A. 
Published: March 2011

ABSTRACTAmorphous hydrogenated silicon carbide alloy films (a-SiC:H) were produced by the decomposition of methane and silane in a glow discharge deposition system. A deposition rate of 13 Å/sec was achieved for good quality films. Amorphous SiC:H films of p+type and n+type of a band gap of 1.86 eV and 1.8 eV and the activation energy of 0.4 eV and 0.23 eV, respectively were obtained. Results show that p+type and n+type a-SiC:H films can be good window layers and good diffusion barriers for indium in polyimide/metal/n-i-p(p-i-n)/ITO amorphous silicon solar cells.
The photosensitivity of a-Si:H/P+Pc-Si heterojunction
Authors: Wang Wanlu , Liao Kejun 
Published: March 2011

ABSTRACTWe have investigated the photosensitivity of the a-Si:H/P+Pc-Si heterojunction. It has been found that the capacitance of a-Si:H/P+Pc-Si heterojunction have an excellent photosensitivity, and potential application as a photosensitive capacitors.
Amorphous Silicon-Based Superlattices and their Potentials to Device Applications
Authors: Hirose Masataka , Murayama Naoki , Miyazaki Seiichi , Ihara Yohji 
Published: March 2011

ABSTRACTTwo types of amorphous silicon (a-Si:H)/silicon nitride (a-Si3 N4 :H) multilayers have been prepared either by turning-off the plasma at each step of individual layer growth (step by step deposition) or by quick gas switching without interrupting the plasma (continuous deposition). It is found that the continuous deposition causes a significant mixing of nitrogen into the a-Si:H well layers and deteriorates the compositional abruptness in the a-Si:H/a-Si3N4 :H interface. Also, undesirable incorporation of nitrogen into the a-Si:H well layers tends to induce nonradiative recombination centers near the interface.
Carrier Separation Effects in Doping Modulated Amorphous Silicon
Authors: Kakalios J. , Tsai C. C. , Street R. A. 
Published: March 2011

ABSTRACTDoping modulated amorphous silicon films have been synthesized which exhibit photoconductivity decay times in excess of 1000 seconds at 78 K. The time and intensity dependence of the photoconductivity is described by a model in which photo-excited charge carriers are spatially separated to separate layers by the built-in pn junction fields and reside in band tail states.
a-SiGe:H Alloy and its Application to Tandem-Type Solar Cell
Authors: Yukimoto Y. , Aiga M. 
Published: March 2011

ABSTRACTAmorphous SiGe:H alloy is the key material in achieving high conversion efficiency with tandem-type amorphous silicon alloy solar cells. Status and issues for this key material are discussed, and efforts made to irprove it are reviewed to obtain directions for higher quality a-SiGe:H alloys. An application of the improved alloy to tandem-type solar cell to achieve 9.6% efficiency for the cell size of 100 cm2 is reported.
High Quality a-Si Films and Superlattice Structure p-Layer a-Si Solar Cells
Authors: Nakano Shoichi , Tsuda Shinya , Tarui Hisaki , Takahama Tsuyoshi , Haku Hisao , Watanabe Kaneo , Nishikuni Masato , Hishikawa Yoshihiro , Kuwano Yukinori 
Published: March 2011

ABSTRACTAs a new preparation method for high-quality a-Si films, we have developed the super chamber, a separated UHV reaction chamber system. A low impurity concentration and excellent film properties were obtained by the super chamber. A conversion efficiency of 11.7% was obtained for an a-Si solar cell using a high-quality i-layer deposited by the super chamber, and a p-layer fabricated by a photo-CVD method.As a new material, amorphous superlattice structure films were fabricated by the photo-CVD method for the first time. Quantization effects and low damage to the interfaces were observed. Superlattice structure p-layer a-Si solar cells were fabricated for the first time, and a conversion efficiency of 10.5% was obtained.
Effects of Light Soaking Conditions on Thin Film Silicon:Hydrogen Alloy Solar Cells
Authors: Willett D. R. , Tanner D. P. , Mchenry G. 
Published: March 2011

ABSTRACTVariation of environmental conditions during light soaking of thin film silicon:hydrogen alloy (TFS) solar cells can have measurable effect on durability. Such sensitivity must be considered in optimizing processes for maximizing long-term performance. This paper will describe the effects of operating temperature, light intensity, operating bias, and duration of light soaking on the stability of TFS p-i-n solar cells.
Double Injection Field Effect Transistor A New Type of Solid State Device
Authors: Hack M. , Shur M. , Czubatyj W. 
Published: March 2011

ABSTRACTWe propose a new general principle of operation for solid state devices, and demonstrate a novel transistor which we call a Double Injection Field Effect Transistor, based on this principle. We have fabricated amorphous silicon alloy double injection transistors, operating on the modulation of a double injection current by a gate field covering the complete path of the current channel.Using these amorphous silicon alloy double injection transistors, we have achieved currents over fourteen times those theoretically possible for conventional amorphous silicon field effect transistors operating under similar conditions. This new principle, applicable to both thin film amorphous and crystalline devices, offers the potential of high current, high speed field effect transistors.
Thin Multi-Layered Photoreceptor Deposited From Disilane
Authors: Araki S. , Nou H. , Kamaji H. , Kiyota K. 
Published: March 2011

ABSTRACTA thin multi-layered photoreceptor drum has been fabricated, using glow-discharge decomposition of disilane. The photoreceptor is thin(10 μm), but it is charged up sufficiently. The photoreceptor has three layers; the p-type a-Si:H (blocking layer), the intrinsic B-doped a-Si:H (photoconductive layer) and a-SiC:H (passivation layer). Disilane is highly reactive. The intrinsic B-doped a-Si:H was prepared from a slightly gaseous mixture of B2H6 (3 ppm). The amorphous-SiC:H passivation layer deposited from Si2H6 and C3H8 was developed to achieve sufficient surface potential and to improve the environmental characteristics.