bluuebunny/crossref_metadata_2025_split huggingface dataset:
Smart Oxygen Diffusion Barrier Based on IrAl Alloy
Authors: Hosoda Hideki , Watanabe Sadao , Hanada Shuji 
Published: April 2011

ABSTRACTIr should be used as an effective oxygen diffusion barrier (ODB) for ultrahigh temperature structural materials since If exhibits extremely low oxygen diffusivity. Oxidation resistance of Ir is, however, not good due to formation of gaseous oxide, IrO3, over 1390K. In this study, the improvement of oxidation resistance was aimed through alloy design of alloying with Al. IrAl is expected to form a self-healing multifunctional layered structure composed of Ir layer as ODB and A12O3 layer as a protective oxide (PO) on the Ir layer. Ar arc-melted IrAl alloy was crushed into powder, followed by hot pressing and heat treatment to remove Ir formed by eutectic reaction. Oxidation behavior was measured using thermogravimetry (TG) and differential thermal analysis (DTA) under the conditions of (1) dynamic heating of 0.167K/s and (2) isotherms at 1273K to 1673K in O2 environment. It was found that oxidation resistance is much improved by alloying with At and that the designed structure (PO/ODB) is formed on the IrAl substrate. Compressive mechanical properties were investigated from RT to 1873K: both the strength as a function of normalized temperature and specific strength are higher than those of pure Ir, NiAl, TiAl and Ni3A1. IrAl is promising as a advanced smart coating material equipping good oxidation resistance as well as high temperature strength.
Modifications 7 And 8 Of Decagonal AI-Co-Ni
Authors: Ritsch S. , Hiraga K. , Beeli C. , Gödecke T. , Scheffer M. , Lück R. 
Published: April 2011

AbstractBesides the six established decagonal states of the Al-Co-Ni quasicrystal two more modifications have been discovered by means of transmission electron microscopy. One is a pentagonal quasicrystal with a superstructure found in specimens with a very high Co-content and quenched from the highest possible temperature lying within the stability field of decagonal Al-Co-Ni. Its electron diffraction patterns are characterized by a 5-fold rotation axis as a unique symmetry element as well as superstructure reflections similar to those of a related decagonal phase. The other is a one-dimensional quasicrystal closely related to decagonal Al-Co-Ni. The modulation length of 61 Å along the periodic direction in its pseudo 10-fold diffraction patterns can be assumed to be caused by a strong linear, uniform, phason strain in the material.
Application Of Quasicrystalline Materials As Thermal Barriers In Aeronautics And Future Perspectives Of Use For These Materials
Authors: S´nchez A. , García de Blas F. J. , Algaba J. M. , Alvarez J. , Vallés P , García-Poggio M. C. , Agüero A. 
Published: April 2011

AbstractQuasicrystalline materials (QCs) have very interesting properties which make them good candidates to be used as coatings resistant to wear, high temperature oxidation, corrosion, etc. The potential application of AI71Co13Fe8Co8 (QC1), a quasicrystalline approximant alloy, as a thermal barrier coating (TBC) for components of aeronautical and power generation turbines was explored in our laboratories and the results are presented in this paper. QC1 is stable at I 1000°C and has a thermal conductivity similar to that of yttria stabilized zirconia (YSZ), the most commonly used material for TBCs. QC1 powders were low pressure plasma sprayed on IN100 superalloy and coatings of excellent quality were obtained after a series of optimization experiments. The “as deposited” coatings were characterized by XRD, SEM and TEM and the results indicated that the coatings retained the same microstructure and phase composition as the bulk material. However, when coated specimens were heat treated at 950°C, interdifussion between coating and substrate took place resulting in the transformation of the QC approximant phase. To avoid or retard this process, the effect of several diffussion barrier layers, deposited between substrate and coating, was studied and the results showed that some of these barriers were quite efficient in slowing the diffusion process. Extensive cyclic oxidation and hot corrosion studies were carried out, showing promising results for this new type of TBC coatings. A short term ground engine test was carried out with coated blades.
Development Of High-Strength Aluminum-Based Alloys By Synthesis Of New Multicomponent Quasicrystals
Authors: Inoue A. , Kimura H. M. 
Published: April 2011

AbstractBy the control of composition, clustered atomic configuration and stability of the supercooled liquid in the rapid solidification and powder metallurgy processes, high-strength Al-based bulk alloys containing nanoscale nonperiodic phases were produced in AI-Ln-LTM, AI-ETM-LTM and Al-(V, Cr, Mn)-LTM (Ln=lanthanide metal, LTM=VII and VIII group metals, ETM=IV to VI group metals) alloys containing high Al contents of 92 to 95 at%. The nonperiodic phases are composed of amorphous or icosahedral (I) phase. In particular, the Al-based bulk alloys consisting of nanoscale I particles surrounded by Al phase exhibit much better mechanical properties as compared with commercial Al base alloys. The success of producing the Al-based alloys with good engineering properties by use of I phase is important for future development of I-based alloys as practical materials.
12.1” Svga Wide Viewing Angle Tft-Lcds Based on Ridge and Fringe-Field Structures
Authors: Lien A. , Cai C. , John R. A. , Galligan E. , Nunes R. , Wilson J. , Ifill H. 
Published: April 2011

ABSTRACTWe have recently proposed the ridge and fringe-field multi-domain homeotropic (RFF-MH) mode for improving viewing angles of thin-film-transistor driven liquid crystal display (TFT-LCD) panels (4). We also demonstrated that the RFF-MH structures are suitable for high resolution desk top TFT-LCD panels (5). In this paper we demonstrated that the RFF-MH method is also suitable for the high-end large-area notebook application since it provides wide viewing angles with a high optical transmission. The ridge structure is constructed on top of the indium tin oxide (ITO) layer of the color filter (CF) substrate, and can be fabricated during the color filter process. The cell process of the RFF-MH panel is compatible to the conventional TFT-LCD cell fabrication process. It requires one extra photolithographic step; however no rubbing treatment is required.
Electron Diffraction Investigation of Crystallographic Texture of Thin Films
Authors: Tang Li , Duan Shanlin , Laughlin David E. 
Published: April 2011

ABSTRACTA method of investigating thin film crystallographic texture by electron diffraction is reviewed. The reciprocal lattices of fibrous and lamellar textured thin films are spherical belts around the texture axis. Equations describing the projection of the spherical belts onto the Ewald sphere along the texture axis direction are presented. Based on these equations the geometric and intensity evolution of the electron diffraction patterns with the tilt angle about an arbitrary axis in the film plane can be analyzed in a systematic way. The geometric characteristics of the electron diffraction patterns are then used to derive the texture axis directional index and its angular distribution. The way to determine the equal-intensity circular arcs on the diffraction pattern is also discussed. This method can be applied to both single layered and multilayered thin films of various applications.
Lattice Parameter Determination of Textured Co81−xCr15PtxTa4 Thin Films
Authors: Lu B. , Harkness S. D. , Lewis W. A. , Laughlin D. E. , Lambeth D. N. 
Published: April 2011

ABSTRACTThe thin films Co81−xCr15PtxTa4 with (0002) crystallographic texture have been sputter deposited with and without substrate bias. The lattice parameter of the thin films has been determined by a combination of x-ray diffraction and electron diffraction techniques. The resolution of the electron diffraction was enhanced by a digital imaging technique. The variation rate of the a lattice parameter with Pt content is consistent with Vegard's law. The change in the c lattice parameter is much greater than what is expected from Vegard's law.
Dislocation Tunneling in Plastically Deformed Aluminum
Authors: Thompson Eunjoo , Pohl R. O. 
Published: April 2011

ABSTRACTWe have measured the amplitude dependent internal friction (ADIF) and sound velocity down to 0.065 K of a 99.9999% (6N) aluminum that was plastically deformed by 1%. The strain amplitude was varied from ε = 1 × 10−8 to ε = 6 × 10−7, a factor of 60. It is observed that with increasing strain amplitude, both the internal friction and the sound velocity become temperature independent over an increasingly wider temperature range. ADIF measurements show a flattening of the temperature dependence of the strain amplitude at low temperatures which is taken to be strong evidence for dislocation tunneling.
C-Axis Perpendicularly Oriented Barium Ferrite Thin Film Media on Silicon Substrate
Authors: Zhuang Zailong , Kryder Mark H. , White Robert M. , Laughlin David E. 
Published: April 2011

ABSTRACTBarium ferrite thin films with excellent perpendicular c-axis orientation were successfully fabricated on Si substrate without any buffer layer. To compensate for possible barium deficiency due to the inter-diffusion between films and substrate, a barium-rich target was used. For a 900 Å-thick film, the perpendicular remanent squareness is about 0.9, while the in-plane remanent squareness is about 0.3. The saturation magnetization (Ms) is about 220 emu/cc, while the coercivity is around 3500 Oe. X-ray diffraction (XRD) results show the (001) perpendicular c-axis texture in the films. It was also found that the rapid thermal annealing conditions greatly affect the magnetic properties of barium ferrite films. With a certain flow rate of oxygen gas in the rapid thermal annealer (RTA), barium ferrite films generally crystallize with good perpendicular c-axis texture. Without oxygen gas, the hexagonal barium ferrite phase fails to develop; instead spinel Fe3O4 phase forms. The reason for the collapsing of hexagonal barium ferrite texture is thought to be an oxygen deficiency in the barium ferrite films due to the reduction of oxygen in the films during the high temperature annealing.
Investigations on in situ Nanocrystallization and Magnetic Properties for Amorphous Fe78Si9B13 Ribbons
Authors: Sun Xiangcheng , Cabral-Prieto A. , Yacaman M. Jose , Sun Wensheng 
Published: April 2011

ABSTRACTThe amorphous state of ferromagnetic Fe78Si9B13 (Metglas 2605S-2) and itsnanocrystallization were investigated by in situ transmission electron microscope (TEM), Xraydiffraction (XRD), Mossbauer spectroscopy (MS), differential scanning calorimeters(DSC) and magnetic moment measurements. The Mössbauer spectrum exhibited anessentially symmetric hyperfine field pattern of 259KOe in as-quenched amorphous state atroom temperature. The Curie and crystallization temperature were determined to beTc=708K and Tx.= 803K, respectively. The Tx value was in good agreement with DSCmeasurement results. The occupied fraction of the nanocrystalline phases of α-Fe(Si) andFe2 at in situ optimum annealing temperature was about 57% and 43%, respectively. It isnotable that the magnetization of the amorphous phase decreases more rapidly withincreasing temperature than those of nanocrystalline ferromagnetism, suggesting thepresence of the distribution of exchange interaction in the amorphous phase or highmetalloid contents.
Structure and Sensor Properties of a Robust GMR Material System
Authors: Lenssen K.-M. H. , Donkers J. J. T. M. , Kuiper A. E. T. , Driel J. VAN 
Published: April 2011

ABSTRACTRecently we have developed a robust GMR material system, based on an artificial antiferromagnet which is exchange-biased with Ir-Mn. By combining magnetoresistance and magnetization measurements with Transmission Electron Microscopy analyses we show that the degree of [111] texture has direct effects on the sensor properties of the GMR multilayer. The degree of texture turns out to depend not only on the buffer layer, but also on the thickness of the Ir-Mn layer. The strongest texture is found for Ir-Mn layer thicknesses of around 4 nm. For this thickness the largest exchange-biasing field and GMR ratio are also obtained (after cooling in a magnetic field), but the blocking temperature is significantly reduced. If attention is paid to the material structure by choosing the right materials, layer thicknesses and stack order, a robust GMR multilayer system can be made that can withstand high temperatures (> 200°C) and strong magnetic fields (> 200 kA/m), as has been demonstrated experimentally.
Electrodeposition of NiFe Thin Films and NiFe/Cu Multilayers with a Recirculating Electrochemcial Flow Reactor
Authors: Myungl N. V. , Ryu K. H. , Kim J. H. , Schwartz M. , Nobel K. 
Published: April 2011

ABSTRACTNano-structured Ni80Fe20NCu multilayers were electrodeposited by a newly developed electrodeposition process utilizing a recirculating electrochemical flow reactor. This process, which operates in an inert gas environment, overcomes the limitations of conventional multilayer electrodeposition methods (single and dual bath techniques) by depositing pure magnetic layers without codeposition of the nonmagnetic metal and oxidation of metal interfaces. Structure, corrosion resistance and magnetic properties of electrodeposited NiFe (0 to 100 % Fe) thin film alloys were first investigated. Three different crystal regions, α, mixed α and γ, and γ phases were observed at <50,;50, >50 % Fe in the deposit, respectively. The narrow mixed phase regions was around 50 % Fe compared to 70–80% Fe for bulk alloys. The lattice parameters of electrodeposited alloys exhibited the same trends as bulk alloys. Maximum corrosion resistance was obtained at 50% Fe content in 0.5 M NaCl similar to bulk alloys. The corrosion resistance of the α phase was an order of magnitude less than the γ phase. The magnetoresistance (MR) of electrodeposited NiFe thin film alloys was higher than bulk alloys. Based on these studies, Ni80Fe20/Cu multilayers with individual layer thicknesses ranging from 100 nm to 1.26 μm have been electrodeposited in the recirculating electrochemical flow reactor. The layer thicknesses were precisely controlled by adjusting the amount of charge passed.
Single Wafer CVD of Silicon Nitride for Cmos Gate Applications
Authors: Pomarede C. , Werkhoven C. , Weidmann J. , Bergman T. , Gschwandtner A. , Houssa M. 
Published: April 2011

ABSTRACTThe MESC/CTMC compatible, Advance 2500 cluster tool made by ASM is evaluated for the manufacturing of CMOS gate stack structures based on CVD silicon nitride rather than thermally grown silicon oxide as the gate dielectric material, and polysilicon as the gate electrode material. With two different CVD chemistries excellent growth characteristics and thickness uniformity control of the silicon nitride is demonstrated. Electrical assessment reveals lower leakage current as compared to silicon oxide and minimal hysteresis in C-V curves, even for gates stacks that have an equivalent oxide thickness below 1.5nm. The best properties are for silicon nitride films that also have a low H2 content.
Ultra-Thin High Quality Silicon Nitride Gate Dielectrics Prepared by Catalytic Chemical Vapor Deposition at Low Temperatures
Authors: Sato Hidekazu , Izumi Akira , Matsumura Hideki 
Published: April 2011

ABSTRACTThis is to report the feasibility of ultra-thin silicon nitride (SiNx) films, prepared by catalytic chemical vapor deposition (Cat-CVD) method, as an ultra-thin gate insulator. In the Cat-CVD method, the deposition gases such as a gaseous mixture of silane (SiH4) and ammonia (NH 3) are decomposed by catalytic cracking reactions with a heated tungsten catalyzer placed near substrates, and SiNx films are formed at substrate temperatures around 300°C without using plasma. In the paper, additionally the effect of post-deposited treatments by using NH3-decomposed species or hydrogen (H2)-decomposed species formed by catalytic cracking of NH3 and H2 are also studied. It is found that a small hysteresis loop is seen in the C-V curve of as-deposited Cat-CVD SiNx films and that the leakage currents with thickness of 3nm equivalent oxide thickness (EOT) is slightly larger than that in the conventional thermal SiO2 of similar EOT. However, it is also found that the properties of Cat-CVD SiNx films are drastically improved by the post-deposited H2 or NH3 treatments, that is, the hysteresis loop disappears and the leakage current decreases by three orders of magnitude.
The Effects of Interfacial Suboxide Transition Regions on Direct Tunneling in Oxide and Stacked Oxide-Nitride Gate Dielectrics
Authors: Yang H. , Niimi H , Wu Y. , Lucovsky G. 
Published: April 2011

ABSTRACTMesarjian et al. were the first to recognize the effects of suboxide interfacial transition regions at Si-SiO2 interfaces on tunneling oscillations in the Fowler-Nordheim regime. This paper extends these ideas to the direct tunneling regime and focuses on differences in interfacial transition regions between Si-SO2 interfaces with, and without monolayer level interface nitridation. Tunneling currents in both the direct and Fowler-Nordheim tunneling regimes are reduced by monolayer level interface nitridation for PMOS and NMOS devices with the same oxide-equivalent thickness. This paper develops a modified barrier layer model based on analysis of XPS results that accounts for these reductions in current in the direct tunneling regime.
Low-Temperature Formation of SiO2 and High Dielectrics Constant Material for ULSI in 21st Century
Authors: Ohmi Tadahiro , Sekinet Katsuyuki , Kaiharat Ryu , Saitot Yuji , Shirai Yasuyuki , Hirayama Masaki 
Published: April 2011

ABSTRACTA high-density plasma processing system featuring a radial line slot antenna has been developed for high-quality thin film formation at low temperature. This system is characterized by a high plasma density (above 1012 cm−3), a low electron temperature (below 1 eV) and a low plasma potential (less than 9 V). High-integrity silicon oxide films grown by direct oxidation of silicon surface at 400°C have been developed by introducing oxygen radical oxidation where oxygen radicals are obtained by a high-density plasma in He/O2 ambient. It is confirmed that the breakdown field intensity of oxide film is more than 15 MV/cm and the charge-to-breakdown is larger than 10 C/cm2under a constant stress current density of 0.1 A/cm2. The same high-density plasma system has also been applied for the direct nitridation of silicon surface using Ar/N2 or Ar/N,/H, gas ambient. The electrical properties of the silicon nitride are excellent enough to extend scaling limit of thermally grown silicon oxide. An advanced gas distribution system consisting of a newly-developed vaporizer, a flow control system, an electrically controlled valve and an advanced gas pumping system can control various source gas concentrations in the process chamber very accurately from the first atomic layer deposition. The newly-developed plasma and advanced gas distribution systems are suitable for the formation of high dielectric constant and ferroelectric films for ULSI in the 21st Century.
Ultrathin Tantalum Pent-Oxide Films for Ulsi Gate Dielectrics
Authors: Nishioka Yasushiro 
Published: April 2011

ABSTRACTUltrathin tantalum pent-oxide (Ta2O5) films with a high dielectric constant over 20 and which are thinner than 10 nm have been extensively studied to realize small area capacitors for memories and high performance MOSFETs. The author and his colleagues started working on ultrathin Ta2O5 films with an equivalent oxide film thickness less than 4 nm for small capacitors for bipolar memories and DRAMS in 1984, and investigated extensively the effects of dry oxygen annealing of sputter-deposited thin Ta2O5 films on Si. We found that there was a process window (dry O2, 800 °C) where defects causing initial and latent breakdown were significantly reduced and where at the same time the reduction in the capacitance inevitably caused by the growth of interfacial SiO2 is kept small. This dry O2 annealing has been widely used for many years due to its effectiveness. This treatment was called “weak spot oxidation.” The interfacial SiO2, with a smaller dielectric constant of 3.9, underneath the Ta2O5 films causes a reduction of the capacitance and an increase of the equivalent film thickness. Annealing of the films after deposition and suppression of the interfacial SiO2 growth are the keys to realizing high performance and reliable Ta2O5 capacitors and gate insulators. In this paper, these fundamental processes are described, along with more recent developments of Ta2O5 thin film technologies, and the potential of the Ta2O5 films as an alternative for a future ULSI gate insulator are also discussed.
Ultrathin TiO2 Gate Dielectric Formation by Annealing of Sputtered Ti on Nitrogen Passivated Si Substrates in Nitric Oxide Ambient
Authors: Luan H. F. , Mao A. Y. , Lee S. J. , Luo T. Y. , Kwong D. L. 
Published: April 2011

ABSTRACTWe have fabricated very thin TiO2 film (Teq∼20Å) by RTP oxidation of sputtered Ti in NO ambient on nitrogen passivated Si substrates. The leakage current is about two orders magnitude lower than SiO2 of identical Teq. Results show that NO passivation layer prior to sputtering is critical in reducing the leakage current. XPS results show that the temperature RTP NO oxidation of sputtered Ti is very important for achieving high quality TiO2 films. high oxidation temperature an SiO2 layer is formed at the interface between TiO2 and Si and the leakage current is approaching to that of SiO2.
Ultrathin Silicon Oxide and Nitride – Silicon Interface States
Authors: Brillson L.J. , Young A.P. , Schäfer J. , Niimi H. , Lucovsky G. 
Published: April 2011

ABSTRACTLocal electronic states at nanometer-thick silicon oxide and nitride films on Si can be studied on an unprecedented scale using low - energy cathodoluminescence spectroscopy to observe optical transitions of defect bonding arrangements at ultrathin film interfaces prepared by low -temperature plasma deposition. Our results illustrate significant differences in the dependence of specific defects at the oxide versus nitride interfaces on thermal annealing and hydrogenation.
JVD Silicon Nitride and Titanium Oxide as Advanced Gate Dielectrics
Authors: Ma T.P. 
Published: April 2011

ABSTRACTThe principle and practice of the Jet-Vapor Deposition (JVD) technique for thin-film deposition will be introduced, followed by a presentation of the properties of ultra-thin JVD silicon nitride (designated SiN in this paper) as advanced MOS gate dielectric. Recent results on the JVD TiO2/SiN gate stack will also be presented
Interfacial Properties of Si-Si3N4formed by Remote Plasma Enhanced Chemical Vapor Deposition
Authors: Misra V. , Lazar H. , Kulkami M. , Wang Z. , Lucovsky G. , Hauser J.R. 
Published: April 2011

ABSTRACTThis paper presents results on the interfacial properties of Si3N4on NMOSFETs and PMOSFETs. Silicon nitride, formed by remote plasma enhanced chemical vapor deposition, was found to display severely degraded interfacial properties, in which the PMOS interfaces were significantly more degraded than NMOS interfaces. This is believed to be indicative of a relatively high density of interface traps located below the Si mid-gap that inhibit hole channel formation. These traps are believed to originate from the intrinsic nature of Si- Si3N4interface. Bonding constraint theory was applied to conclude that the Si-Si3N4interface is over-constrained compared to the Si-SiO2interface and consequently results in a higher intrinsic defectivity. A systematic study of the oxygen and hydrogen content in the silicon nitride film and its effect on electrical properties is also presented. Based on the electrical results it is concluded that the presence of oxygen either as a) a monolayer at the interface or b) within the silicon nitride film can produce high quality interfaces suitable for aggressively scaled CMOS devices.