bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extendibility Study of a PVD Cu Seed Process with Ar+ Rf-Plasma Enhanced Coverage for 45nm Interconnects
Authors: Simon Andrew H. , Bolom Tibor , Tang Teck Jung , Baker Brett , Peters Carsten , Rhoads Bryan , Flaitz Philip L. , Sankaran Sujatha , Grunow Stephan 
Published: April 2011

ABSTRACTWe present the results of a systematic benchmarking study, using 45nm-groundrule structures, of a commercially-available ionized PVD Cu technology which employs an in-situ Ar+ radio-frequency (Rf) plasma capability for enhanced coverage, and compare its performance and extendibility against the same seedlayer process operated in conventional low-pressure mode. Studies of single-damascene lines and dual-damascene via structures indicate that the PVD Cu seedlayer with Rf-Plasma enhancement enables a reduction of the PVD Cu seed thickness on the order of 35%, based on studies of Cu voiding, via-yield degradation, and transmission-electron microscopy (TEM). These results illustrate the critical importance of the Rf-plasma resputter capability in extending the PVD Cu process to advanced groundrules at 45nm and beyond.
TVS Measurements of Metal Ions in Low-k Dielectrics: Effect of H2O Uptake
Authors: Ciofi Ivan , Tökei Zsolt , Mangraviti Giovanni , Beyer Gerald 
Published: April 2011

ABSTRACTDrift of metal ions in low-k dielectrics was investigated by Triangular Voltage Sweep (TVS) measurements on planar capacitors with different gate materials: Al, Ta, Ru, Ti, Cu, Pt and a-Si.
Plasma Modification Of Si-O-Si Bond Structure in Porous Sioch Films
Authors: Dultsev Fedor N , Urbanowicz Adam M , Baklanov Mikhail R 
Published: April 2011

ABSTRACTPlasma modification of SiOCH low-k films is analyzed by means of Molecular Mechanics. It is shown that the most probable mechanism of SiOCH modification in He plasma is removal of hydrogen atoms from CH3 groups. The change of Si–O–Si bond angles depends on the amount of the formed –CH2* (CHx) groups. During the followed exposure in NH3 plasma, NH2* radicals bind CHx groups with Si forming a –CH2– Si–O–Si–O–Si–O–Si– chain. The end of this chain gets bound to its beginning through NH2. This process is the reason of pore sealing.
Using a Barrier Layer to Inhibit Ti/Oxide Reaction to Reduce RC Delay and Improve Electromigration in Al-Cu/Ti/W Interconnect for High Power Analog and Mixed Signal Applications
Authors: Murphy William , Lee Tom C , Chapple-Sokol Jonathan , Delibac Daniel A , He Z. X. , Luce Stephen E , Mongeon Stephen A , Thomas David C , Vanslette Daniel S , Sullivan Timothy D 
Published: April 2011

ABSTRACTIn this paper, we report a novel method to improve aluminum interconnect electromigration performance, reduce metal line sheet resistance (Rs) and reduce via contact resistance (Rc) in a minimum pitch design. We report the effects of bottom redundancy layers on electrical line and via resistance and upstream electromigration performance. We studied 4 metallization stacks: (I) Ti/TiN/AlCu/Ti/TiN, (II) Ti/TiN/Ti/AlCu/Ti/TiN (annealed at 400°C for 20 minutes), (III) a flash process/stack I, (IV) stack III with aluminum deposition temperature of 250°C. Aluminum deposition temperature in stacks I, II, and III are 200°C. Bottom Ti/TiN, AlCu, and Top Ti/TiN layers have the same thickness for all these stacks. Metal line Rs and via contact resistances (Rc) of stack IV are 5% and 10% lower, respectively, than stack I. Stack II metal line sheet resistance is 15% higher than stack I, which is attributed to Al consumption in the TiAl3 formation during 400°C/20minutes annealing. Electromigration performance is best with stack IV followed by III, II, then I.
Degradation of ZnO nanowire devices under the ambient condition
Authors: Kim Dong-Wook , Choi Soo-Han , Ji Hyun-Jin , Kim Sang Woo , Moon Seung Eon , Park So Jung , Kim Gyu-Tae 
Published: April 2011

ABSTRACTField effect transistors(FETs) made of ZnO nanowires are very sensitive to the gas environment, so that the passivation can be a good way to get reliable nanowire FETs with longer lifetime and the better mobility. The studies on the passivation effects with the positive electron-beam resist was investigated by selectively covering the part of nanowire devices between the electrodes. Reproducible electrical characteristics were recorded, reflecting the stable electrical properties by the passivation which deters the degradation of a device. Considering the defect states of oxide nanowires dominate the charge states, the pre-state just before the passivation process will be crucial to understand the reproducible and controllable device characteristics of nanowire devices.
CMOS Compatible Synthesis of Carbon Nanotubes
Authors: Uchino Takashi , Bourdakos Konstantinos N. , Ayre Gregory N. , de Groot Cornelis H. , Ashburn Peter , Smith David C. 
Published: April 2011

ABSTRACTA technique to synthesize high-quality single walled carbon nanotubes (SWNTs) using chemical vapour deposition (CVD) on Ge Stranski-Krastanow dots has been developed. From transmission electron microscopy and Raman measurements, the grown carbon nanotubes (CNTs) are identified as SWNTs with diameters ranging from 1.6 to 2.1 nm. Extensive scanning electron microscopy and atomic force characterisation of the effect of each stage in the growth process is presented. Our hypothesis is that pre-treatment stages lead to the formation of Ge nanoparticles, which act as seeds for CNT growth. This technique demonstrates the ability to synthesize high-quality SWNTs without the need for a metal catalyst, using processes and equipment standard to a silicon foundry.
Synthesis and Properties of Carbon Nanotube Yarns and Textiles
Authors: Schauer Mark , Lashmore David , White Brian 
Published: April 2011

ABSTRACTThe strength of macroscopic materials made of carbon nanotubes depends on the quality of the nanotubes produced, as well as various methods of post-treatment. The average diameter and length of the nanotubes can be controlled through the various parameters of a specially designed injector system, in conjunction with the CVD furnace. Large non-woven textiles and yarns of pure nanotubes are created, and then post-processed in various ways to obtain the desired products. In this way textiles over 2 square meters, and yarns of over a half kilometer have been produced with strengths unprecedented in pure carbon nanotube materials.
Immobilization of CNT on Bamboo Charcoal by TEOS Vapor
Authors: Zhu Jiangtao , Kwong Fung Luen , Ng Dickon Hang Leung 
Published: April 2011

ABSTRACTCarbon nanotubes (CNTs) are successfully immobilized on a bamboo charcoal by chemical vapor deposition of gaseous tetraethyl orthosilicate (TEOS). Electron microscopies, Raman spectroscopy and electron energy loss spectroscopy are used to characterize the sample. The CNTs found on the bamboo charcoal support were several microns long, and their diameters ranged from 50nm to 300nm. From the high resolution transmission electron microscopic analysis, we found that the CNTs were composed of ∼30 layers of graphitic carbon sheets. Amorphous droplets were also found at the tips of the CNTs. This suggested that the growth of the CNT was via a vapor-liquid-solid mechanism. The amorphous droplets contained calcium, silicon and oxygen. The calcium impurity was originated from the bamboo while the silicon impurity was supplied by the TEOS. CNTs partially filled with calcium silicate were also found. It was evident that calcium silicate had played a critical role in the formation of these CNTs.
Use of Saccharides as Solid-state Precursors for the Synthesis of Carbon Nanotubes
Authors: Kucukayan Gokce , Kayacan Serim , Baykal Beril , Bengu Erman 
Published: April 2011

ABSTRACTSaccharides, ranging from simple table sugar (sucrose) to lactulose were successfully used as solid-state precursors for the synthesis of multi-walled carbon nanotubes (MWCNT). Dehydrated saccharide residues mixed with catalyst powders were subjected to pyrolysis at high temperatures (up to 1300°C) under flowing Argon atmosphere. Pyrolysis products were investigated using TEM, SEM, Raman spectroscopy and EDS. Images taken using the S/TEM and bright field mode of TEM showed the presence of helical multi-walled carbon nanotube (H-MWCNT) and regular MWCNT formation. More than two or three catalyst particles were observed to be present inside the hollow core of some of the nanotubes synthesized, suggesting a high level of capillary activity inside the tubes during synthesis.
Measurement of Ultrafast Carrier Dynamics in Epitaxial Graphene
Authors: Dawlaty Jahan M. , Shivaraman Shriram , Chandrashekhar Mvs , Spencer Michael G. , Rana Farhan 
Published: April 2011

ABSTRACTUsing ultrafast optical pump-probe spectroscopy, we have measured carrier relaxation times in epitaxial graphene layers grown on SiC wafers. We find two distinct time scales associated with the relaxation of nonequilibrium photogenerated carriers. An initial fast relaxation transient in the 70-120 fs range is followed by a slower relaxation process in the 0.4-1.7 ps range. The slower relaxation time is found to be inversely proportional to the degree of crystalline disorder in the graphene layers as measured by Raman spectroscopy. We relate the measured fast and slow time constants to carrier-carrier and carrier-phonon intraband and interband scattering processes in graphene.
Evaluation of the Stiffness of Carbon Nanotube Probe by Force Curve Measurements
Authors: Hirooka Motoyuki , Okai Makoto , Tanaka Hiroki , Sekino Satoshi 
Published: April 2011

AbstractBuckling of arc discharge made multi-walled carbon nanotubes with various lengths was studied by alternating the length of a multi-walled nanotube by intermittent cutting. Buckling stresses were determined by measuring force-distance curves employing an atomic force microscope and the values were compared with those expected from the Euler's theoretical model. As the length of a nanotube was shortened, its buckling mode changed from elastic compressive bending with Young's modulus of 1.2TPa, to inelastic compressive fracture. The inelastic behavior observed for short nanotubes can be attributed to the buckling mechanism, in which ripple-like distortions develop along the nanotube sidewalls.
Preliminary Measurements of Selective Sensing of DMMP and NH3 Using CNTFET Array Based Gas Sensors Fabricated Using Metal Diversified Electrodes for Electronic Fingerprinting
Authors: Bondavalli Paolo , Legagneux Pierre , Pribat Didier 
Published: April 2011

AbstractThis paper deals with preliminary measurements for prove-of-concept of a Carbon Nanotubes Field Effect Transistors (CNTFETs) based sensor array which could improve dramatically gas selectivity. CNTFET based sensors exploit the extremely sensitive change of the Schottky barrier heights between Single Wall Carbon NanoTubes (SWCNTs) and drain/source metal electrodes: the gas adsorption creates an interfacial dipole that modifies the metal work function and so the bending and the height of the Schottky barrier at the contacts [1,2]. Using CNTFET array fabricated using SWCNT mat as channel, we have achieved a sort of electronic fingerprinting of different gases. Actually, we want to demonstrate that the change of the metal electrode work function strictly depends on the metal/gas interaction : CNTFET transfer characteristics will change specifically as a function of this interaction. In this study we have fabricated different CNTFETs using three metal contacts (Au, Pd, Mo) and exposed them to two gases, DMMP and NH3, which have the same “electron-withdrawing” behavior. The CNTFETs array has been exposed to 1ppm of DMMP and 10ppm NH3 and we have identified two electronic fingerprinting. The totality of our measures have been performed at ambient conditions.
Nanotube Potential Future in Nuclear Power
Authors: Popa-Simil Liviu 
Published: April 2011

AbstractThe nanotubes presents high potential of applications in nuclear power, integrating them both in advanced fuels developments nano-breeding and in nano-shielding. The carbon nanotubes may be successfully used to create fuel wires used in high temperature applications and near perfect burning generating new procedures in nuclear reactor waste management while reducing the waste by two orders of magnitude. The modified nanowire may hold various other materials as conductors and insulators being useful in direct conversion of the nuclear energy into electricity, by including in the center a sequence of high and low electron density conductors. As direct conversion structures they can handle all the required functions into a nuclear reactor or energy harvesting blanket to assure high power density, high efficiency and minimal waste. Another very challenging application is the usage of nanotube to channel low energy nuclear radiation and guide it, similar to the GHz wave-guides or to hundreds of THz optic fibers. The operation domain of the nanotubes is placed mainly in the domain of UV to X rays, being the role of composite structures or nanowire channeling to cover the gamma ray domain. The carbon nanotubes may become useful cold neutrons transport devices with directive capabilities as short bending or focusing. The theoretical approaches and simulations predicted these new application capabilities of nanowires for nuclear materials with exceptional properties.
Ionic Liquid Based CO2 Capturing Fuel Cell for Greenhouse Gas Reduction
Authors: V. Wolkin Michal , Stumpp Raphael , Littau Karl 
Published: April 2011

ABSTRACTRoom-temperature ionic liquids are utilized in a new CO2 capturing fuel cell. The cell is aimed at the efficient and cost effective removal of CO2 emitted from transportation related sources. The CO2 is captured from the atmosphere and is later converted into carbon free synthetic fuel such as methanol. In this study we optimized the operating conditions and the cell electrolytes. With ionic liquids such as 1-Butyl-1-methylpyrrolidinium dicyanamide, the extraction efficiencies increased to ∼20% while simultaneously making the capture process more robust. The ionic liquid approach is also compared to existing aqueous electrochemical CO2 concentration previously proposed by NASA for aerospace applications but with much lower efficiencies.
Compact Modelling of Electrical, Mechanical and Thermal Behaviour for MEMS with SPICE
Authors: Frank Andreas , Zoellner J.-P. , Sarov Y. , Ivanov Tz. , Kuhnholz I. , Klett St. , Rangelow I. W. , Swiatkowski M. , Gotszalk T. , Nikolov N. 
Published: April 2011

ABSTRACTIn this paper we present a novel method of nonlinear macro model of a cantilever for mixed domain simulation only with SPICE. Based on lumped elements of equivalent circuits a model is developed, which realizes a coupled electro-thermal-mechanical simulation including crosstalk effects. The model is verified with measurement and helps to class and solve crosstalk. With SPICE as electrical circuit simulator the cantilever array could be simulate in conjunction with the excitations and analysis electronics more detailed like the system level models and faster like FEM-simulation.
Dielectric-barrier discharge plasma source and its application to synthesis of diamond like carbon films
Authors: Wang Xinpeng , Tang Xiaoliang , Feng Peter Xianping 
Published: April 2011

ABSTRACTDielectric barrier discharge plasma sources have been studied and used for syntheses of diamond like carbon thin films. The plasma electrical properties under different gases concentrations and pressures were diagnosed. Based on the results of characterizations, dielectric barrier discharge plasma at different methane-hydrogen-argon gas ratios was used to synthesize large area of diamond like carbon films. Experimental data indicate that only at argon concentration equal to or less than 75% diamond like carbon film fabrication could be accomplished, which has been confirmed based on the Raman spectra and their hardness measurements, whereas high argon content during deposition would result in graphite type of thin films.
Thermal Characterization of Micro/Nanoscale Wires/Tubes Using Pulsed Laser-assisted Thermal Relaxation
Authors: Guo Jiaqi , Wang Xinwei , Geohegan David , Eres Gyula , Vincent Cecile 
Published: April 2011

ABSTRACTA novel transient technique is developed to measure the thermal diffusivity of one-dimensional microscale wires. In this technique, the thin wire is suspended over two copper electrodes. Upon fast (nanosecond) pulsed laser irradiation, the wire's temperature will quickly increase to a high level and then decrease gradually. Such temperature decay can be used to determine sample's thermal diffusivity. To probe this temperature evolution, a dc current is fed through the wire to sensor its voltage variation, from which the thermal diffusivity can be extracted. A 25.4-μ;m thin Pt wire is characterized to verify this technique. Sound agreement is obtained between the measured data and reference value. Applying this pulsed laser-assisted thermal relaxation technique, the thermal diffusivity of multi-wall carbon nanotube bundles and microscale carbon fibers is measured. Detailed analysis is conducted to study the effect of the wire embedded in the paste/base on the final measurement result.
Electrical Switching Using Compliant Metal Infiltrated Multi-Wall Nanotube Arrays
Authors: Bult Justin , Sawyer W. Gregory , Voevodin Andrey , Muratore Chris , Dickrell Pam , Pal Sunil , Ajayan Pulickel , Schadler Linda 
Published: April 2011

ABSTRACTThe topology of conventional noble-metal-coated switch counterfaces creates modes of switch failure via fouling, arcing, and local melting when impacted. To avoid these failure phenomena, compliant conductive contact surfaces of vertically aligned multi-wall nanotube arrays grown on conductive substrates have been fabricated. Infiltration of the array by noble metal results in a robust compliant switch contact surface. Cyclic hot-switch testing of the nanotube based switch, via modified nano-indentation, results in performance surpassing conventional designs with stable resistance of 0.4Ω over 3000 cycles. Investigating the physical performance of the array shows the array is compacted less than 3% over the first 500 cycles with no observable compaction through the remaining cycles. The improvement in performance of the nanotube based switch is attributed to the ability for the compliant contact surface to conform to the probe tip geometry, increasing the effective contact surface area.
Moisture Effects on Gold Nanowear
Authors: Pendergast Megan , Volinsky Alex A. , Pang Xiaolu , Shields Robert 
Published: April 2011

ABSTRACTThe addition of water results in the higher wear rate of gold compared to experiments performed in the ambient environment (approximately 60% humidity). This higher wear rate in water has been observed with the AFM, Hysitron Triboindenter, and additionally in single pass scratch tests performed with the Taber Shear/Scratch tester. These tests were preformed using silicon nitride cantilevers on the AFM and a conical diamond tip in the Taber instrument. Tests performed in the ambient atmosphere resulted in slightly reduced surface roughness, while much higher wear rate was observed in the wear tests performed in water. Ambient scratch tests produced slightly shallower scratch trenches than wet scratches consistently as a function of the varied normal load. Single scan lines provide valuable information about the mechanisms and progression of the nanoscale wear. The different components of scratch friction are investigated to explore the main contributors to the nanoscale scratching of gold.
Fractal Dimensions of Soy Protein Nanoparticle Aggregates determined by Dynamic Mechanical Method
Authors: Jong Lei 
Published: April 2011

AbstractThe fractal dimension of soy protein aggregates can be estimated by dynamic mechanical methods when the particle aggregates are imbedded in a polymer matrix. Composites were formed by mixing hydrolyzed soy protein isolate (HSPI) nanoparticle aggregates with styrene-butadiene (SB) latex, followed by freeze-drying and compression molding methods. The dynamic shear moduli of the elastomeric composites containing different particle fractions were measured. A logarithmic plot of shear modulus vs. particle fraction in rubber plateau region at 140 oC can be fitted with a linear line. From the slope of the fitted line, the fractal dimension of the particle aggregates was estimated using the Cluster-Cluster Aggregation (CCA) model developed by Kluppel and Heinrich. The CCA model can also be used to extract fractal dimension from dynamic strain sweep experiments. The reversible strain sweep data was then fitted with a CCA model expression developed by Huber and Vilgis to yield the fractal dimension of the particle aggregates. The results show that the fractal dimensions extracted from both linear and non-linear viscoelastic data have a good agreement with each other. The model fitting indicates HSPI has a greater fractal dimension and therefore a more compact structure than the un-hydrolyzed soy protein aggregates.
Simulations of an Interface Crack Nucleation During Nanoindentaion : Molecular Dynamics and Finite Element Coupling Approach
Authors: Hara Shotaro , Izumi Satoshi , Sakai Shinsuke , Eguchi Yoshiyuki , Iwasaki Tomio 
Published: April 2011

AbstractWe carried out the nanoindentation simulations for the Ru (superlayer) / Cu (film) / SiO2 (substrate) system using the finite temperature MD-FEM coupling method. The calculations are performed for the different adhesion energies of Cu/SiO2 ranging from 0.2 to 0.6 J/m2. During loading, it was found that the interfacial crack nucleation occurs at three to four times the contact radius, driven by the tensile stress acted on the Cu/SiO2 interface. We also show that the asymmetric defect behavior have a great effect on giving birth to the crack nucleation. The observation of our simulation indicates that the mechanism of the crack nucleation strongly depends on the interfacial bonding energy.
Stress Assisted Grain Growth in Ultrafine and Nanocrystalline Aluminum Revealed by in-situ TEM
Authors: Mompiou Frederic , Legros Marc , Caillard Daniel 
Published: April 2011

AbstractIn-situ straining experiments on nanocrystalline (nc) and ultra fine grain (UFG) Aluminum were performed at room and intermediate temperatures. Both materials exhibit significant stress assisted grain growth. The strain induced by grain boundary motion has been measured in UFG Al, and was found to be on the order of a few percents. These results cannot be interpreted solely within the framework of Displacement Shift Complete (DSC) dislocation motion. We propose here that GB motion occurs via both shuffling and secondary DSC dislocation motion.
Kinetic- or Thermodynamic-Growth Formation of Pd Nanocrystals: a combined TEM-DLS Approach
Authors: Berhault Gilles , Bausach Marta 
Published: April 2011

AbstractThe kinetics of formation of palladium nanoparticles with well-defined morphologies (rods, cubes, MTP icosahedra, bipyramids) was studied using a combination of TEM and dynamic light scattering (DLS). The present study was focused on the role of the concentration and the size of seeds on both the kinetics of growth and the morphology distribution. Results clearly emphasize the role of the seed concentration (and not the size) on the growth kinetics in agreement with a collision theory model.