bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nano-Scale MOSFET Devices Fabricated Using a Novel Carbon-Nanotube-based Lithography
Authors: Derakhshandeh Jaber , Abdi Yaser , Mohajerzadeh Shams , Beikahmadi Mohammad , Behnam Ashkan , Arzi Ezatollah , Robertson Michael D. , Bennett C. J. 
Published: April 2011

AbstractPECVD-grown carbon nanotubes on (100) silicon substrates have been studied and exploited for electron emission applications. The growth of CNT's is achieved by a mixture of hydrogen and acetylene gases in a CVD reactor and a 2-5nm thick nickel is used as the seed for the growth. The presence of DC-plasma yields a vertical growth and allows deposition at temperatures below 650°C. The grown nano-tubes are encapsulated by means of an insulating TiO2 layer, leading to beam-shape emission of electrons from the cathode towards the opposite anode electrode. The electron emission occurs using an anode-cathode voltage of 100 V with ability of direct writing on a photo-resist coated substrates. Straight lines with widths between 50 and 200nm have been successfully drawn. Scanning electron and transmission electron microscopy have been used to investigate the quality and fineness of the results. This technique has been applied on P-type (100) silicon substrates for the formation of the gate region of N-MOSFET devices, showing a drive current of 310μA/μm and Cox of 0.7μF/cm2.
Diffraction from Periodic Arrays of Oxide-Filled Trenches in Silicon: Investigation of Local Strains
Authors: Eberlein Michel , ESCOUBAS Stephanie , GAILHANOU Marc , THOMAS Olivier , ROHR Pascal , COPPARD Romain 
Published: April 2011

AbstractThe experimental evaluation of stresses at the nanometer scale is a real challenge. We propose an innovative use of High Resolution X-Ray Diffraction to measure local strains induced in silicon by periodic arrays. This technique is non-destructive and allows for the measurement of periodic strain fields in monocrystalline silicon, created in particular by Shallow Trench Isolation process. A 0.58μm-period array of trenches filled with SiO2 gives rise to satellites in reciprocal space maps around the Si substrate peak. The intensity and envelope of these satellites depend on the local strain. The experimental reciprocal space maps are compared to those computed using the kinematical theory from the elastic displacement field calculated with finite element modelling. This technique allows us to study the generation of strain during the main steps of the STI process. During the process, after trenches get filled with oxide and top layers removed, a second diffraction peak appears with a lower intensity than the substrate one. Thanks to finite element modelling, we validate that this peak is caused by an almost constant strain in the silicon active areas. Typical values of strains after trench filling are -1.68*10-3 along × and 1.56*10-3 along z where × and z refer to transverse and perpendicular directions.
Morphological and Structural Evolution of an Ultra-low-k Dielectric During the Porogen Removal
Authors: Rebiscoul Diane , Trouvé Héléne , Remiat Bruno , Clerc Laurence , Louis Didier , Passemard Gerard 
Published: April 2011

AbstractThe use of porous ultra-low-k materials between interconnections for sub 45nm technologies has introduced some barrier diffusion and mechanical problems. In order to avoid the problems caused by the porosity, a hybrid dense material (porogen and matrix) can be used in an alternate integration scheme. In this approach, the porogen is removed after CMP steps by a thermal cure or UV assisted thermal cure. In this work, we have first characterized the impact of the temperature and the duration of the thermal cure on the material. The crosslinking degree increases and the porogen amount decreases with increasing cure temperature. The most important impact of the curing duration happens between 350°C and 400°C. The increase of the curing duration leads to an increase of the porogen loss and a decrease of the refractive index. Secondly, in order to assess the structure of the layer as a function of the depth, the material was etched in a 0.05% HF solution and then characterized. According to the temperature and duration of the cure, the etch-rate can vary as a function of the material depth. This variation is related to a complex gradient inside the material.
Methodology to Determine the Toughness of a Brittle Thin Film by Nanoindentation
Authors: Brillet-Rouxel Helene , Verdier Marc , Dupeux Michel , Braccini Muriel , Orain Stéphane 
Published: April 2011

AbstractNanoindentation is the most convenient local technique for measuring elastic modulus, hardness, and fracture toughness of dielectric thin films. This approach is applied to bulk silicon and dielectric thin films (porous and non-porous) on silicon substrate. Reproducible stable cracks are generated from the edges of a cube corner indentor. The validity of theoretical model of use to estimate the toughness from cracks length has been checked on these reference cases. To calculate the toughness of thin film on Si substrate, we first established the loading range in which the cracks only affect the thin film without substrate damage. Several corrective terms have been introduced to the classical toughness estimation formula to take into account the proximity of the film/substrate interface and the residual stress pre-existing in the film. This approach is discussed by comparing experimental results obtained including these improvements to literature results.
Low-k Dielectric Obtained by Noble Gas Implantation in Silicon Oxide
Authors: Assaf Hanan , Ntsoenzok E. , Ruault M-O. , Ashok S. 
Published: April 2011

AbstractThermally-grown 220nm-thick silicon oxide layers were implanted at room temperature with 300keV Xe at doses ranging from 0.5 to 5x1016Xe/cm2. As-implanted samples exhibit bubbles in silicon oxide for all doses. Annealing at T≤400°C results in the disappearance of bubbles from SiO2 layer for the dose of 1x1016Xe/cm2. But for the higher doses of 3.5 and 5x1016Xe/cm2, the bubbles are very stable and remain in the sample even after very high thermal annealing. Capacitance measurements show a strong decrease in the dielectric constant k of the implanted SiO2 sample from 4 (reference sample) to 1.5.
The Effect of Plasma Damage on the Material Composition and Electrical Performance of Different Generations of SiOC(H) Low k Films
Authors: Humbert Aurelie , Badaroglu Didem Ernur , Hoofman Romano J.O.M 
Published: April 2011

AbstractThe degradation of SiOC(H) low-k films upon plasma treatments has been investigated. Three generations of SiOC(H) low-k dielectrics (k=3.0, k=2.6 and k=2.3) were used. The low-k materials have been exposed to N2O, NH3, O2, H2, He, Ar and N2 based plasmas, representing the most commonly-used plasmas during interconnect integration. For all plasma-treated samples, an increase in k-value and decrease in breakdown voltage was observed. These observations could be attributed to chemical degradation, in particular to carbon depletion and OH-bond formation. The latter leads to moisture adsorption, which was confirmed by contact angle measurements and FTIR spectra. The N2O plasma treatment was found to be the most aggressive for all low-k dielectrics studied. It drastically increases the k-value and the leakage current and results in complete carbon removal on the top-surface. This effect is most pronounced on the most porous material. On the other hand, an in-situ helium plasma shortly after low-k deposition enhances the resistance to chemical degradation upon exposure to other plasmas, even for the most aggressive ones. For the argon and reactive pre-clean plasmas, only small compositional changes were observed. In conclusion, it can be said that not only the plasma treatments have to be tuned in accordance with the low k integration requirements, but also attention has to be paid to limit moisture absorption during integration.
Influence of Grain Orientation on the Microstructural Characterization in Cu During (self)-Anneal using a Surface Acoustic wave Technique
Authors: Sekiguchi Atsuko , Vanstreels Kris , DeMuynck Steven , D'Haen Jan , Brongersma Sywert H 
Published: April 2011

AbstractThis paper describes the influence of microstructure, or more specifically grain orientation and grain size, on the in-line monitoring of copper interconnect properties during (self)-anneal using surface acoustic wave spectroscopy (SAWS). In electroplated Cu after (self)-anneal the SAWS frequency is lower for samples annealed at higher temperature because of the lower porosity induced elasticity. In sputtered Cu, the SAWS frequency shows a clear correlation with grain size, which is induced by a strong re-orientation of the copper film from the as-deposited (111) texture (E=190 GPa) to a strongly (100) textured super grain structure (E=78GPa).
A Novel MO Precursor for Metal Tantalum and Tantalum Nitride Film
Authors: Sekimoto Kenichi , Furukawa Taishi , Oshima Noriaki , Tada Ken-ichi , Yamakawa Tetsu 
Published: April 2011

AbstractA novel tantalum precursor, bis(ethylcyclopentadienyl)hydridocarbonyltantalum (Ta(EtCp)2(CO)H EtCp:ethylcyclopentadienyl), for chemical vapor deposition (CVD) and atomic layer deposition (ALD) was synthesized. The molecular structure of this precursor was determined by 1H and 13C NMR, IR, ICP-AES and elemental analysis. This precursor is liquid at room temperature, and its vapor pressure and decomposition temperature indicates that this precursor is suitable for CVD and ALD process.The composition analysis of metal tantalum films deposited by thermal CVD revealed that the concentration of carbon was larger than tantalum. On the other hand, an argon plasma CVD technique reduced the carbon concentration drastically.
Cu Resistivity in Narrow lines: Dedicated Experiments for Model Optimization
Authors: Maitrejean Sylvain , Gers Roland , Mourier Thierry , Toffoli Alain , Passemard Gérard 
Published: April 2011

AbstractAs the dimensions of interconnects shrink, the confinement effects associated with a very small grain size lead to a significant increase in the resistivity of the metal. Cu resistivity models have been proposed using the classical Fuch and Sondheimer approach for surface effect, and the Mayadas and Shatzkes approach for the grain boundary effect. In these models, three adjustable parameters must be used. Good agreement between experimental data and models can easily be obtained. However, numerous fitting parameter sets can be used with equivalent fitting quality and opposite physical meaning. In this work, experiments dedicated to model parameter extraction are proposed and released. They are based on the used of Cu lines with various line widths and heights. Classical resistivity increase with line width and line height decrease is observed. The resistivity behaviour is modelled. In this case, limited fitting parameter options are obtained. For Cu narrow lines confined with Ta, these parameters suggest maximum surface effect, medium grain boundary effect and low impurity content inside the lines.
The Copper Corrosion and Sulfur Contamination Generated by a Three-Step Copper Chemical-Mechanical Polishing Process
Authors: Liu Chun-Ping , Ho Yen-Shih , Hu Tien-Chen , Tseng Bae-Heng 
Published: April 2011

AbstractThis article shows the root cause of Cu corrosion and sulfur contamination due sulfite vapor reflow through drainpipe of load cup to the original three-step Cu CMP equipment. Now, we provide a solution which to modify the arrangement of the drainpipe in original three-step Cu CMP equipment. This is an effective implement for reduction the defects of Cu corrosion and sulfur contamination from long-term observations.
Relationship Between Interfacial Adhesion and Dielectric Reliability of Cu Alloy Films
Authors: Yi Seol-Min , Jang Kwang-Ho , Huh Yong-Hak , Park Young-Bae , Joo Young-Chang 
Published: April 2011

AbstractCu alloy has been suggested to enhance reliabilites in future technology. To evaluate the effects of alloying elements on electrical and mechanical reliabilities, Mg and Ru were chosen as alloying elements. Because alloying elements to Cu should not increase resistivity over comparable value to pure Cu, the resistivity of pure Cu, Cu-0.7at%Mg alloy and Cu-2.2at%Ru alloy was compared. Time dependent dielectric breakdown (TDDB) under bias-temperature stress (BTS) tests were accomplished to evaluate the effect of alloying elements on dielectric reliability. The standard four point bending experiments were conducted to measure critical interfacial adhesion energy of conducting metal to SiO2. The relationship of the effect of alloying elements on reliabilities to distribution of alloying elements was analyzed using Auger Electron Spectroscopy (AES). Our results show alloying Mg to Cu can enhance reliability by forming self-passivating layer on its surface and interface while Ru does not.
Novel Reducing Chemistry for Supercritical Fluid Deposition of Copper
Authors: Momose Takeshi , Ohkubo Tomohiro , Sugiyama Masakazu , Shimogaki Yukihiro 
Published: April 2011

AbstractWe study new deposition chemistry in Cu-SCFD (supercritical fluid deposition), especially effect of acetone is investigated as reducing agent and additives into H2 reducing Cu-SCFD. Acetone reduction yields Cu film deposition onto Ru coated Si substrate, because Ru has catalytic effect to generate reducing agent from acetone. When acetone is added into H2 reducing chemistry, the solubility of precursor is enhanced approximately 50 %, which is so-called “entrainer effect”. Ethanol can enhance the deposition of Cu in H2 reduction chemistry, which is a solvent effect. Two effects of entrainer effect by acetone and solvent effect by ethanol works independently, without interfering each other.
Feasibility Study for Usage of Diluted Fluorine for Chamber Clean Etch Applications as an Environmental Friendly Replacement of NF3
Authors: Hellriegel Ronald , Hintze Bernd , Winzig Hubert , Albert Matthias , Bartha Johann W. , Schwarze Thomas , Pittroff Michael 
Published: April 2011

AbstractDeposition steps in CVD and ALD applications usually not only cover the surface of the substrate surface but also the walls of the chamber inside. Regular removal of those residuals has to be done to obtain stable and repeatable deposition results with uniform surfaces at acceptable particle levels. The high requirements to sustain stable processes has lead to more frequent chamber cleans. NF3 has emerged as the main clean gas for remote clean applications. While it meets the above mentioned requirements and is considered to fit easily into the fab gas supply it is relatively expensive. The work presented here investigates argon/nitrogen diluted fluorine (F2) as an alternative clean gas with a significantly reduced environmentally destructive global warming emission (GWP). The cleaning behaviour with respect to different materials (SiON, TaN, TiN, W, SiO2) was studied. It is found that in general argon/nitrogen diluted fluorine achieves etch rates comparable to those obtained by NF3 when the comparison is based on the amount of fluorine transported into the reactor.
Silicon Microchannel Array as a Basis of Biosensor Device
Authors: Lomzov Alexander , Vandysheva Natalia , Bublikov Alexander , Pyshnyi Dmitry , Romanov Sergei 
Published: April 2011

AbstractThis work shows the possibilities of using the silicon-based microchannel array (Si-MCA) as a 3D-solid support of DNA probes and studying of application of optical methods for DNA hybridization direct analysis. It was obtained that amount of immobilized oligodeoxyribonucleotides on the Si-MCA surface is enhanced with lighting of Si-MCA microchannel. The sample of 160 μm thickness succeeded in immobilizing oligonucleotides 40 times as much as the standard glass slides having the same external surface. The application of Si-MCA as a carrier of DNA allows doing direct analysis of nucleic acids in infrared region by the FTIR method that essentially simplifies creation of a biosensor based on the Si-MCA. It is indicated that using of the Si-MCA as a diffraction grating in visible and UV spectra allows simplifying the spectral analysis of biochemical reaction. It was success confidently to distinguish the mediums differing on the refractive index by dn=0.006.
Electrospun Tungsten Oxide Nanofibers: Fabrication and Characterization
Authors: Wang Guan , Huang Xianrong , Yang Xiaoqing , Gouma Pelagia-Irene , Dudley Michael 
Published: April 2011

AbstractTungsten oxide nanofibers have been successfully fabricated in a way based on electrospinning technique. A DMF solution of Poly(Vinyl Acetate)(PVAc, Mw=500,000) was mixed with tungsten isopropoxide to form a viscous precursor solution. Composite nanofibers were obtained by electrspinning this viscous solution. By calcination of the composite fibers, pure tungsten oxide nanofibers were obtained with controllable diameters of around 100 nm. Morphology of the fibers has been characterized by SEM and TEM. The relationship between solution concentration and ceramic nanofiber morphology has been studied. The detailed structure evolution process has been investigated by synchrotron based in-situ XRD. Specific phases of the oxide nanofibers at various calcination temperatures have been obtained from the in-situ XRD spectrum.
Formation of Highly Porous Gas-sensing Films by In-situ Thermophoretic Deposition of Nanoparticles from Aerosol Phase
Authors: Sahm Thorsten , Rong Weizhi , Barsan Nicolae , Mädler Lutz , Friedlander Sheldon K. , Weimar Udo 
Published: April 2011

AbstractGas sensors based on tin dioxide nanoparticles show high sensitivity to reducing and oxidizing gases. Dry aerosol synthesis applying the flame spray pyrolysis was used for manufacture and directly (in-situ) deposit nanoparticles on sensor substrates. For the first time this technique has been used to synthesize a combination of two stacked porous layers for gas sensor fabrication. Compared to state-of-the-art techniques, aerosol technology provides a direct and versatile method to produce homogeneous nanoparticle films. Two different sensing layers were deposited directly on interdigital ceramic substrates. These porous bottom layers consisted either of pure tin dioxide or palladium doped tin dioxide. The top layer was a palladium doped alumina nanoparticle film which served as a chemical filter. The fabricated gas sensors were tested with methane, CO and ethanol. In case of CH4 detection, the pure tin dioxide sensor with the Pd/Al2O3 filter layer showed higher sensor signals and significantly improved analyte selectivity with respect to water vapor compared to single tin dioxide films. At temperatures up to 250°C the Pd-doping of the tin dioxide strongly increased the sensitivity to all gases. At higher temperatures the sensor signal significantly decreased for the Pd/SnO2 sensor with a Pd/Al2O3 filter on top indicating high catalytic activity.
Zinc Oxide Thin Films used as an Ozone Sensor at Room Temperature
Authors: Pimentel Ana Claudia , Gonçalves Alexandra , Marques António , Martins Rodrigo , Fortunato Elvira 
Published: April 2011

AbstractIn this paper we present results of intrinsic/non doped zinc oxide deposited at room temperature by rf magnetron sputtering able to be used as a semiconductor material on electronic devices, like for example ozone gas sensors and ultra-violet detectors. The produced films are polycrystalline with a c-axis preferential orientation parallel to the substrate. The films present a resistivity that varies from 4.0×10−2 Ωcm to 1.0×109 Ωcm depending on the deposition conditions used in this study (rf power density and oxygen partial pressure) without changing the optical properties (an average transmittance of 85 % and an optical band gap energy &#8776;3.44 eV). When exposed to UV light the sensor response exceeds more than 5 orders of magnitude recovering to the initial state in the presence of ozone. The sensitivity of the films is improved when the oxygen partial pressure increases and the rf power density decreases which are directly related to the structural properties of the films.
Nanoparticle Metal-Oxide Films on Microhotplate Platforms: Fabrication and Gas-Sensitive Properties
Authors: Tomchenko Alexey , Marquis Brent 
Published: April 2011

AbstractIn this presentation, we discuss the development of nanostructured sensor materials based on nanoparticulate metal-oxide suspensions deposited onto MEMS μHPs by microprinting. The preparation of the suspensions is described; the precise control over the thickness of the films through the composition of the metal-oxide suspensions is demonstrated. The procedure of microprinting is described. The deposited films are evaluated as chemical sensors. The sensor performance of the microsensors – sensitivity, stability, speed of operation, and selectivity – is compared with that of analogous traditional thick-film sensors.
Investigation of a Novel Light-blue-emitting Fluorescent Guest/Host System with Excellent Lifetime
Authors: van Gemmern Philipp , Grabowski Stefan P. , Boerner Herbert , van Elsbergen Volker , Löbl Hans-Peter , Young Edward , Heil Holger , Fortte Rocco , Becker Heinrich , Heuken Michael , Kalisch Holger , Jansen Rolf H. 
Published: April 2011

AbstractIn this work, organic light emitting devices (OLEDs) based on a blue-emitting fluorescent guest/host-system from Merck OLED Materials GmbH is investigated. OLEDs comprising a hole transport layer (HTL), the emissive film Merck Blue Host:Merck Blue Guest (MBH:MBG), a hole-blocking film and the electron transport layer (ETL) were prepared by vacuum thermal evaporation. The hole-blocking capabilities of aluminum(III)bis(2-methyl-8-quinolinato)4-phenylphenolate (BAlq) and the host material MBH were investigated. By employing an additional HBL, the current efficiency could be increased from 5.7 to 7.4 cd/A. Furthermore, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane (F4-TCNQ) doping of the HTL was investigated. Devices with 4,7-diphenyl-1,10-phenanthroline (BPhen) or 1,3,5-Tris-(N-phenylbenzimidazol-2-yl)benzene (TPBI) as alternative ETLs were fabricated and conclusions were drawn regarding the charge balance in the devices. It was found that employing tris-(8-hydroxyquinoline) aluminum (Alq3) as ETL leads to the best lifetimes of about 2000 hours at a constant current of 20 mA/cm2 while p-doping in combination with BPhen as ETL leads to the highest efficiency of 5.7 lm/W max. and 4.4 lm/W at 1000 cd/m2.