bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Role of Stress on the Shape of the Amorphous-Crystalline Interface and Mask-Edge Defect Formation in Ion-Implanted Silicon
Authors: Ross Carrie E. , Jones Kevin S. 
Published: April 2011

ABSTRACTStress is known to affect the regrowth velocities during recrystallization of an amorphous layer. This study investigates how the stress from patterned structures alters regrowth and in turn affects defect formation. Prior to patterning, 80Å SiO2 and 1540Å of silicon nitride were deposited on a 200 mm [001] silicon wafer. A 40keV Si+ amorphizing implant at a dose of 1×1015 atoms/cm2 was then performed into the patterned wafer. The regrowth of the amorphous layer along the mask edge was studied by partially recrystallizing the layer for various times at 550°C both with the mask present and after etching off the oxide and nitride pads. A significant number of cross-sectional Transmission Electron Microscopy (TEM) samples were prepared and imaged. It was found that the stress from the patterned structures enhances the vertical and lateral regrowth velocities, as well as alters the shape of the amorphous-crystalline interface during regrowth. Previous studies have shown that uniaxial tensile stress increases the regrowth velocity. Simulations show that the region of interest in these samples is under tensile stresses, suggesting that this type of stress should accelerate the regrowth velocity. In addition dislocation half loops are observed to form along the mask edge for certain structures. The nucleation of these defects is suppressed by the presence of the film. The relationship between the stress from the patterned structures, the regrowth of the amorphous layer, and the formation of dislocation half-loops along the mask edge will be discussed.
Formation and Morphology Evolution of Nickel Germanides on Ge (100) under Rapid Thermal Annealing
Authors: Lee K.Y. , Liew S.L. , Chua S.J. , Chi D.Z. , Sun H.P. , Pan X.Q. 
Published: April 2011

ABSTRACTPhase formation and interfacial microstructure evolution of nickel germanides formed by rapid thermal annealing in a 15-nm Ni/Ge (100) system have been studied. Coexistence of a NiGe layer and Ni-rich germanide particles was detected at 250°C. Highly textured NiGe film with a smooth interface with Ge was observed. Annealing at higher temperatures resulted in grain growth and severe grooving of the NiGe film at the substrate side, followed by serious agglomeration above 500°C. Fairly low sheet resistance was achieved in 250-500°C where the NiGe film continuity was uninterrupted.
Effects of Alloying on Properties of NiSi for CMOS Applications
Authors: Dal Mark van , Akheyar Amal , Kittl Jorge A. , Chamirian Oxana , Pottera Muriel De , Demeurisse Caroline , Lauwers Anne , Maex Karen 
Published: April 2011

ABSTRACTEffects of alloying Ni with Pt and Ta on silicide properties for CMOS technology have been studied. It was found that Pt is soluble in NiSi, which is in line with literature, whereas Ta segregates towards the surface during thermal treatment. Additionally, Ta retards NiSi formation at low temperature. Thermal stability of NiSi on Si is improved more efficiently by alloying Ni with Pt compared to Ta. Silicide/diffusion contact resistance is extracted using the Transmission Line Structure. In our experiments, contact resistivity appeared to be virtually unaffected with respect to the alloying element. Thermal stability on narrow poly Si structures was also improved when Ni was alloyed with Pt. Similar leakage currents for Ni and Ni(Pt) silicides on N+ and P+ junctions were obtained. The results presented in this work suggest that Pt is a better candidate as alloying element to improve NiSi thermal stability for CMOS processes than Ta.
Indium in silicon: interactions with native defects and with C impurities
Authors: Alippi P. , Magna A. La , Scalese S. , Privitera V. 
Published: April 2011

ABSTRACTEquilibrium geometries and formation energies of neutral and charged In complexes with silicon native defects (vacancy (V) and self-interstitials (I)) and with C impurities are investigated within density functional theory, using the Vienna Ab-initio Simulation Package. We determine formation energies and ionization levels of different complexes and discuss the contribution of I and V to indium diffusion. We also identify the In-C defect responsible for the increased electrical activation in In+C-doped silicon samples. The ab initio energetics is then implemented in a continuum diffusion code in order to simulate the diffusion of as-implanted In profiles under different thermal treatments.
Study of BF2 ion implantation into crystalline silicon : Influence of fluorine on boron diffusion
Authors: Ihaddadene-Lecoq Lilya , Marcon Jerome , Ketata Kaouther 
Published: April 2011

ABSTRACTWe have investigated and modeled the diffusion of boron implanted into crystalline silicon in the form of boron difluoride BF2+. Low energy BF2+ 1×1015 cm−2 implantations at 2.0keV were characterized using Secondary Ion Mass Spectrometry (SIMS) in order to measure dopant profiles. RTA was carried out at 950°C, 1000°C, 1050°C and 1100°C during 10s, 20s, 30s and 60s. The results show that concentration profiles for BF2+ implant are shallower than those for a direct B+ ion implantation. This could be attributed to the presence of fluorine which trap interstitial Si so that interstitial silicon supersaturation is low near the surface.
Self-Assembled Monolayers as Model Substrates for Atomic Layer Deposition
Authors: Whelan Caroline M. , Demas Anne-Cécile , Schuhmacher Jörg , Carbonell Laureen , Maex Karen 
Published: April 2011

AbstractOur understanding of the role of the initial surface on atomic layer deposition (ALD) of Cu diffusion barrier materials is limited by the complexity of the sequential reactions and the heterogeneous nature of typical dielectric substrates. The atomically controlled surface chemistry of self-assembled monolayers (SAMs) provides a means of creating model substrates for ALD. Here we report on ALD of WCxNy films on SAMs derived from bromoundecyltrichlorosilane adsorbed on silicon dioxide. The as-prepared SAM is macroscopically ordered with the expected Br-termination and has a well-defined chemical composition as determined by contact angle measurements and X-ray photoelectron spectroscopy, respectively. Temperature programmed desorption spectroscopy confirms that the SAM is stable to 550°C. It survives multiple cycles of ALD at 300°C as evidenced by the detection of mass fragments characteristic of the alkyl chain and supported by the persistence of a Br 2p peak at 71 eV. X-ray fluorescence, ellipsometry and atomic force microscopy reveal that the underlying SAM influences WCxNy film coverage, thickness, and morphology.
In-situ XPS Study of ALD Ta(N) Barrier Formation on Organosilicate Dielectric Surface
Authors: Liu Junjun , Bao Junjing , Scharnberg Michael , Ho Paul S. 
Published: April 2011

AbstractBeams of nitrogen and hydrogen radicals were investigated as surface pre-treatment and process enhancement techniques for atomic layer deposition (ALD) of tantalum nitride barrier layer on a dense organosilicate (OSG) low k film. In-situ x-ray photoelectron spectroscopy (XPS) studies of the evolution of the low k surface chemistry revealed an initial transient growth region controlled mainly by the substrate surface chemistry. Pre-treatment of the low k surface with radical beams, particularly with nitrogen radicals, was found to enhance significantly the chemisorption of the TaCl5 precursor on the OSG surfaces. The enhancement was attributed to the dissociation of the weakly bonded methyl groups from the low k surface followed by nitridation with the nitrogen radicals. In the subsequent linear growth region, atomic hydrogen species was able to reduce the chlorine content under appropriate temperature and with sufficient purge. The role of the atomic hydrogen in this process enhancement is discussed.
Barrier Layer Morphological Stability and Adhesion to Porous Low-κ Dielectrics
Authors: Saxena R. , Cho W. , Rodriguez O. , Gill W. N. , Plawsky J. L. 
Published: April 2011

AbstractTwo particularly important reliability issues facing the integration of low- κ dielectric films are the fracture energy of the barrier-dielectric interface and the barrier layer integrity during processing. We have noticed that the compressive stresses in the barrier layers on low- κ dielectrics lead to spontaneous delamination and formation of telephone-cord like morphologies. These morphologies allow the measurement of fracture energy and are advantageous over artificially contrived features to yield realistic debonding parameters. The fracture energy of common barrier films, TaN and Ta, was determined using this method for varying porosity nanoporous silica and MSQ. Detailed characterization of the telephone cord morphology using a combination of Optical Microscopy, SEM and Profilometry was done. The fracture energy for Ta on different low-κ dielectrics was evaluated using a 1-D model for straight buckles. The kinetic coefficient of buckling was also evaluated.
Atomic Layer Deposition of Tantalum Nitride on Organosilicate and Organic Polymerbased Low Dielectric Constant Materials
Authors: Straten Oscar van der , Zhu Yu , Rullan Jonathan , Topol Katarzyna , Dunn Kathleen , Kaloyeros Alain 
Published: April 2011

AbstractA previously developed metal-organic atomic layer deposition (ALD) tantalum nitride (TaNx) process was employed to investigate the growth of TaNx liners on low dielectric constant (low-k) materials for liner applications in advanced Cu/low-k interconnect metallization schemes. ALD of TaNx was performed at a substrate temperature of 250°C by alternately exposing low-k materials to tertbutylimido-tris(diethylamido)tantalum (TBTDET) and ammonia (NH3), separated by argon purge steps. The dependence of TaNx film thickness on the number of ALD cycles performed on both organosilicate and organic polymer-based low-k materials was determined and compared to baseline growth characteristics of ALD TaNx on SiO2. In order to assess the effect of the deposition of TaNx on surface roughness, atomic force microscopy (AFM) measurements were carried out prior to and after the deposition of TaNx on the low-k materials. The stability of the interface between TaNx and the low-k materials after thermal annealing at 350°C for 30 minutes was studied by examining interfacial roughness profiles using cross-sectional imaging in a high-resolution transmission electron microscope (HR-TEM). The wetting and adhesion properties of Cu/low-k were quantified using a solid-state wetting experimental methodology after integration of ALD TaNx liners with Cu and low-k dielectrics.
Silver Patterning by Reactive Ion Beam Etching for Microelectronics Application
Authors: Gao L. , Gstoettner J. , Emling R. , Wang P. , Hansch W. , Schmitt-Landsiedel D. 
Published: April 2011

AbstractDry etching of silver for the metallization in microelectronics is investigated. Etching is performed using an electron-cyclotron-resonance reactive-ion-beam-etching system (ECR-RIBE) in an Ar/CF4 or Ar/CF4/O2 mixture. The etch characteristics are strongly affected by ion energy (beam voltage and microwave energy); the O2 concentration in the reactive mixture has only a small effect. An anisotropic, smooth etch profile and clean surface are obtained. Focused ion beam (FIB) and atomic force microscopy (AFM) have been used to study the etched profile and the roughness, respectively.
Novel Opto-Electronic Braid System with Kumihimo-Structure as a New Concept of Flexible Electronics
Authors: Tanaka Kuniaki , Kuniyoshi Sigekazu 
Published: April 2011

AbstractFollowing the new concept proposed as an opto-electronic integrated system with “textile structure”, we propose here another integrated system-concept of flexible electronics based on “braid structure”. The braid integrated system forms electronic equipment constructed by the filamentous body. Opto-electronic integrated circuits are constructed with Kumihimo-structure by weaving more than three threads on which various devices, and components, such as, transistors, photoelectric transducers, contact-electrodes, pads for wiring and other passive components of circuits are mounted periodically.From the experience of the designing of some basic logic circuits, the Kumihimo-structure weaved by eight-threads of two groups is proposed as a basic structure of the integrated circuit for application to single track braid system. Characteristics and elemental technologies of the braid system are analyzed for the extension of the concept. Application area of the system and requirements for the system are discussed. The braid system is also discussed in flexible electronics concept.
Degradation of MEH-PPV due to Oxygen/Moisture Traps through C-V Analysis and Attenuated Total Reflection IR Spectroscopy
Authors: Khillan R. K. , Su Y. , Varahramyan K. 
Published: April 2011

AbstractWe present the studying of oxygen and moisture traps in MEH-PPV through the MIS Capacitance – Voltage (C-V) analysis, and the Attenuated Total Reflection Infrared (ATR IR) spectroscopy technique. The presence of oxygen studied by ATR IR has also been verified by optical images from high resolution optical microscope. In quasi-static C-V measurements of the MIS (Al/MEH-PPV/p-Si) capacitors made, an extension of the weak inversion region was measured before strong inversion, which becomes more pronounced with aging. This increase in the weak inversion region is attributed to electron trapping by oxygen to form negative ions in the MEH-PPV layer. ATR IR spectroscopy shows the formation of carbonyl peak at 1651 cm−1 with aging, which is due to the presence of oxygen. Both the C-V analysis and Attenuated Total Reflection IR Spectroscopy are powerful tools for investigating the degradation of MEH-PPV polymer.
Large area p-i-n flexible image sensors
Authors: Vieira M. , Louro P. , Fernandes M. , Schwarz R. , Schubert M. 
Published: April 2011

AbstractLarge area p-i-n image sensors deposited on plastic substrates were produced at low temperatures (110 °C) by PE-CVD and compared with similar sensors deposited on glass substrates. The same sensing element structure ZnO:Al/p(SiC:H)/i(Si:H)/n(SiC:H)/Al was used for both devices. In this work the efforts are focused mainly on the optimization of the output characteristics of the sensor when fabricated on plastic substrates. The role of the sensor configuration and readout parameters in the image acquisition process is analyzed. The optical- to-electrical transfer characteristics show a reasonable quantum efficiency under a red light pattern, broad spectral response, and reciprocity between light and image signal.First results show that the sensors deposited on flexible substrate present smaller light to dark sensitivity than those deposited on glass. In both, the non ohmic behavior of the transparent conductive oxide front contact blocks the carrier collection and leads to a surprising linear dependence of the image signal with the applied voltage.
Resolving Orientation Correlations in Deformation Structures by EBSD
Authors: Pantleon Wolfgang 
Published: April 2011

AbstractFor visualization of orientation inhomogeneities in crystalline material orientation imaging maps are conventionally used, with different colors representing different orientations. Two different approaches are proposed to extract more information from the orientation data on deformation structures gathered by electron back-scattering diffraction. First, a statistical approach is introduced for obtaining the chord length distribution of a grain structure and, secondly, an evaluation scheme is presented to resolve the details of the deformation structure within individual grains.
Ca2RuO4Thin Film Growth by Pulsed Laser Deposition
Authors: Wang Xu , Xin Yan , Lee Hanoh , Stampe Patricia A. , Kennedy Robin J. , Zhou Zhixian , Zheng Jim P. 
Published: April 2011

AbstractBulk Ca2RuO4 is an antiferromagnetic Mott insulator with the metal-insulator transition above room temperature, and the Neel temperature at 113 K. There is strong coupling between crystal structures and magnetic, electronic phase transitions in this system. It exhibits high sensitivity to chemical doping and pressure that makes it very interesting material to study. We have epitaxially grown Ca2RuO4 thin films on LaAlO3 substrates by pulsed laser deposition technique. Growth conditions such as substrate temperature and O2 pressure were systematically varied in order to achieve high quality single-phase film. Crystalline quality and orientation of these films were characterized by X-ray diffractometry. Microstructure of the thin films was examined by transmission electron microscopy. The electrical transport properties were also measured and compared with bulk single crystal.
Piezoelectric – Ferromagnetic Interface Engineering for Voltage Driven Coercivity Changes
Authors: Eyckmans Wouter , Borghs Gustaaf , Boeck Jo De 
Published: April 2011

AbstractFerromagnetic thin films were combined with piezoelectric substrates with the purpose of obtaining voltage controllable magnetization behavior. The interface between the ferromagnetic and piezoelectric material was examined for optimized voltage controlled magnetic response. Magneto Optic Kerr Effect (MOKE) measurements, supported by atomic force microscopy (AFM), showed the need to polish the piezoelectric substrates to a roughness below 1nm RMS (1*1νm2scan) for a minimum coercivity of 3kA/m. The magnetic anisotropy dependence on deposition, and anneal temperature was determined, and was shown to cause temperature driven coercivity changes up to 45 A/Km. A buffer layer between the piezoelectric substrate and the ferromagnetic thin film doubled the relative importance of the voltage driven magnetic effects.
Zinc oxide nanocluster formation by low energy ion implantation
Authors: Muntele I. , Thevenard P. , Muntele C. , Chhay B. , Ila D. 
Published: April 2011

ABSTRACTVariable size nanocluster embedded in silicon substrate were obtained by low energy implantation methods. We used optical spectroscopy to measure the optical properties of the implanted samples. The implantation parameters like the ions energy, dose and sputtering rate were calculated with SRIM [13]. Most of the implanted Zn ions (83%) clustered and oxidized during the implantation process, with the remaining 17% being oxidized during annealing in air.
Electrical Properties of ZnO Thin Films Deposited by Pulsed Laser Deposition.
Authors: Heluani S. P. , Simonelli G. , Villafuerte M. , Juarez G. , Tirpak A. , Braunstein G. , Vignolo F. 
Published: April 2011

ABSTRACTStructural and electronic transport properties of polycrystalline ZnO thin films, prepared by pulsed laser deposition, have been investigated. The films were deposited on glass and Si3N4/Si substrates using O2 and N2 atmospheres. X-ray analysis revealed preferential c-axis orientation perpendicular to the sample substrate. Films deposited under relatively high O2 pressure were highly resistive. However, the conductivity σ increased while the films were irradiated with ultraviolet light, showing an Arrhenius (In σ ∝ T-1) dependence as a function of temperature. The ZnO film deposited in N2 atmosphere exhibited at room temperature a resistivity ∼ 1 Ω cm, and a sheet carrier concentration ∼ 5 1012 cm-2. The variation of the conductivity with temperature, in the range 60 – 150 K, follows a In σ ∝ T-1/4 dependence characteristic of variable range hopping. An analysis of the experimental results of conductivity as a function of temperature, in terms of possible doping effects, as well as conduction mechanisms is presented.
Dispersion Engineering of Three-Dimensional Silicon Photonic Crystals: Fabrication and Applications
Authors: Venkataraman Sriram , Schneider Garrett , Murakowski Janusz , Shi Shouyan , Prather Dennis W. 
Published: April 2011

ABSTRACTIn this paper, we propose the design and fabrication of buried silicon optical interconnect technology, the sub-surface silicon optical bus (S3B). The proposed approach relies on engineering the dispersion properties of embedded silicon three-dimensional photonic crystals to create sub-micron routing channels and control light propagation. Further, we present a method for the fabrication of buried three-dimensional (3D) photonic-crystal structures using conventional planar silicon micromachining. The method utilizes a single planar etch mask coupled with time-multiplexed, sidewall-passivating, deep anisotropic reactive-ion etching, to create an array of spherical voids with three-dimensional symmetry. Preliminary results are presented that demonstrate the feasibility of realizing chip-scale optical interconnects using our proposed approach.
Growth of Nonpolar (1100) Films and Heterostructures by Plasma-Assisted Molecular Beam Epitaxy
Authors: Brandt Oliver , Sun Yue Jun , Ploog Klaus H. 
Published: April 2011

ABSTRACTWe discuss the growth of M-plane GaN films and (In, Ga)N/GaN multiple quantum well (MQW) structures on LiAlO2(100) substrates by plasma-assisted molecular beam epitaxy. The adsorption and desorption kinetics of Ga on M-plane GaN is studied by reflection high-energy electron diffraction, allowing us to identify the optimum growth conditions with regard to surface morphology. Furthermore, we investigate the compositional profile of M-plane (In, Ga)N/GaN MQWs grown under conditions resulting in comparatively abrupt interfaces. The results demonstrate that significant In surface segregation occurs for the case of M-plane (In, Ga)N. The dependence of the transition energies of the M-plane MQWs on the actual well thickness reveals, however, that the structures are indeed free of electrostatic fields along the growth direction.
Dependence of the E2 and A1(LO) modes on InN fraction in InGaN epilayers
Authors: Hernández S. , Cuscó R. , Artús L. , O'Donnell K.P. , Martin R.W. , Watson I.M. , Nanishi Y. , Kurouchi M. , Van der Stricht W. 
Published: April 2011

ABSTRACTThe behavior of the E2 and A1(LO) optical phonons in Inx Ga1-x N has been analyzed by Raman scattering over the whole composition range. The frequencies of the E2 and A1(LO) modes decrease with increasing InN fraction. These modes display a significant broadening for an InN fraction of ≈ 60% and their linewidth decreases towards both ends of the composition range as a consequence of reduced cation disorder. Our results show a one-mode behavior for both E2 and A1(LO) modes of InGaN.
Thermally stable transparent Ru-Si-O Schottky contacts for n-type GaN and AlGaN
Authors: Kaminska E. , Piotrowska A. , Golaszewska K. , Lukasiewicz R. , Szczesny A. , Kowalczyk E. , Jagodzinski P. , Guziewicz M. , Kudla A. , Barcz A. , Jakiela R. 
Published: April 2011

ABSTRACTWe have developed the deposition and studied the electrical characteristics and thermal reliability of Ru-based contacts on n- type GaN as well as on AlGaN/GaN heterostructure. Amorphous, conducting and transparent RuSiO4 contacts with their extremely low reverse currents and thermal stability up to 900°C, show great potential for use as Schottky contacts to n-type GaN and gate electrodes for AlGaN/GaN HEMT in high temperature, high power applications as well as in UV detectors.