bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effects of the Addition of CF4, Cl2, and N2 TO O2 ECR Plasma on the ETCH Rate, Selectivity and Etched Profile of RuO2 Film
Authors: Lee Eung-Jik , Kim Jong-Sam , Kim Jin-Woong , Baik Ki-Ho , Lee Won-Jong 
Published: April 2011

ABSTRACTIn this study, we investigated the effects of the addition of CF4, Cl2, and N2 gases to oxygen electron cyclotron resonance (ECR) plasma on the reactive ion etching (RIE) properties of RuO2 film such as etch rate, selectivity, and etched profile. The concentration of the etching species in the plasma was analyzed with an optical emission spectroscopy (OES) and a quadrupole mass spectrometer (QMS). The etch product was also examined with QMS.The addition of a small amount of CF4, Cl2, or N2 to the O2 plasma increases the concentration of oxygen radicals and accordingly increases the etch rate of the RUO2 films appreciably. The etch rate of the RuO2 film was enhanced more with the addition of a small amount of CF4 and CI2 than with the addition of N2. On the contrary, the etched profile obtained in O2/N2 plasma was superior, without any damaged layer at the sidewall, to O2/CF4 and O2/Cl2 plasma. The selectivity of RuO2 to Si)2 mask was over 20:1 for each of the additive gas proportion at which the etch rate was maximum for each plasma system.
Characterization of Highly Textured PZT Thin Films Grown on LaNiO3 Coated Si Substrates by MOCVD
Authors: Lin C. H. , Yen B. M. , Chen Haydn , Wu T. B. , Kuo H. C. , Stillman G. E. 
Published: April 2011

ABSTRACTHighly textured PbZrxTi1−xO3 (PZT) thin films with x= 0-0.6 were grown on LaNiO3 coated Si substrates at 600 °C by metal-organic chemical vapor deposition (MOCVD). The preferred crystalline orientation of PZT thin films with various Zr concentration were characterized by X-ray diffraction (XRD). Microstructures were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The dielectric constants, hysteresis and fatigue behavior of these thin films were also measured. The relationship between growth rate and the preferential orientation is discussed. Furthermore, the dependence of the electrical properties on Zr concentration and preferential orientation is demonstrated.
Ir Electrodes for Ferroelectric Capacitors
Authors: Jung Sung Won , Bang Ilhwan , Lee Jaegab , Kim Jiyoung 
Published: April 2011

ABSTRACTIn this study, Ir/IrO2 mixture electrodes are fabricated by furnace oxidation of sputter deposited Ir, IrO2 and their hybrid electrodes. The characteristics of furnace oxidation of various electrode stems with Ir family and their limitation are investigated. Annealing at higher than 700°C oxidation results in formation of undesirable extrusions in Ir electrode. When the Ir oxide facet extrusions are formed, Ir near at the extrusion is used up and SiO2 substrate are exposed. In addition, furnace oxidized Ir/Ti electrode is suggested as an alternative electrode, which shows smooth surface, good thermal stability, high oxygen contents and low resistivity.
Characterization of New SBT Sol System and its thin film on the Platinum Electrode for Fram Application
Authors: Choi YongSoo , Kim WooSik , Kim ChangEun , Yoo WhanSik , Kim BaeYeon , Song HanSang 
Published: April 2011

ABSTRACTStable SBT sols for FRAM application were made from Sr-isopropoxide, Bi-acetate, and Ta-ethoxide with 2-ethoxyethanol as a solvent and chelating agent, TEA. The sol were spin-on coated on the Pt /Ti/SiO2/Si substrate. From the IR and DTA/TGA, the 2-ethoxyethanol -triethanolamine sol system is quite stable against aging. 5% excess Bi added sol and 800°C heat treatment of the thin film revealed the most crystallinity. There is a change in the orientation of thin film above 800°C heat treatment from c-axis to(105). The average grain size of thin film is very small, i.e., 40 nm at 800°C, and it has very narrow distributions, and the thickness of the coating were about 100nm, which would promise smaller electrode area and higher yield.
CMOS Compatible Integrated PZT Capacitors
Authors: Evans Joe T. , Boyer Leonard L. , Suizu Robert I. , Velasquez Geri 
Published: April 2011

ABSTRACTThe fabrication of high yielding ferroelectric capacitors on CMOS wafers is difficult due to the negative impact of post-capacitor process steps, especially the interlayer dielectric and the metal interconnect sinter. Proper selection of the process for each layer of the capacitor structure is necessary to minimize hysteresis damage to the ferroelectric capacitors during their construction. The authors fabricated integrated PZT capacitors on blank silicon wafers using lift off processes for the bottom and top electrodes and a combination titanium dioxide/silicon dioxide dielectric between the ferroelectric capacitors and the metal interconnect layer. A 15 minute nitrogen anneal at 450 degrees centigrade after the metal interconnect patterning did not damage the capacitor hysteresis loops. Statistical testing of over 700 capacitors for shorts indicated a defect rate of 127 defects per square centimeter. This is sufficiently low enough to generate 50% yield in a production 64Kbit double-sided-sense nonvolatile memory. At 3.5V, the capacitors generated 14.0 microcoulombs per square centimeter with a standard deviation of 2.3 microcoulombs per square centimeter. The authors have set a target for future lots of 20 defects per square centimeter with 32 microcoulombs per square centimeter at 2.0V with a standard deviation of 1.6 microcoulombs per square centimeter.
Leakage Degradation in BST Dielectric Capacitors with Oxide and Metal Electrodes
Authors: Fukushima N. , Abe K. , Izuha M. , Kawakubo T. 
Published: April 2011

ABSTRACTLeakage degradation under DC stresses in epitaxially-grown Ba1−xSrxTiO3/SrRuO3 capacitors with various top electrodes was examined. Epitaxial capacitors employed in this study exhibit higher dielectric constant arising from optimized lattice deformation caused by lattice mismatch between Ba1−xSrxTiO3 and SrRuO3; dielectric constant for SrRuO3/30nm thick Bal-xSrxTiO3/SrRuO3 all oxide capacitor was 550, which corresponds SiO2 equivalent thickness of 0.21 nm. In addition, this type of capacitors have interfaces of higher cleanliness between dielectrics and electrodes, which are expected to provide opportunities of more simplified discussions on reliability issues for thin film capacitors. Dielectric breakdown properties and DC stress-induced leakage degradation properties were examined in room temperature and elevated temperatures. Various kinds of leakage degradation were observed and categorized in anode degradation and cathode degradation. The degradation in capacitors with oxide electrodes was markedly suppressed compared to that in capacitors with metal electrodes such as Pt or Ru. This higher degradation resistance yielded longer lifetime in capacitors of this type and the estimated life time at 458K for SrRuOS/ Bal-xSrxTiO3/SrRuO3 capacitor was 3E8 seconds, which exceeds required specification for DRAM application. These differences were discussed on the basis of a supposed degradation mechanism in which oxygen vacancy generation at anode interface is taken into account as well as vacancy accumulation at cathode interface.
Microstructure Control of (Ba, Sr)TiO3 Films for Gigabit Dram
Authors: Shen H. , Kotecki D. E. , Murphy R. J. , Zaitz M. , Laibowitz R. B. , Shaw T. M. , Saenger K. L. , Baniecki J. , Beitel G. , Klueppel V. , Cerva H. 
Published: April 2011

ABSTRACT(Ba, Sr)TiO3 films were deposited on Pt-coated SiO2/Si wafers by the MOCVD method. Experiments were conducted to investigate the mechanisms of nucleation and growth. It was observed that the diameter of the (Ba, Sr)TiO3 grains is established in the early stages of nucleation and does not increase substantially during the growth of the film. By controlling the process conditions, it is possible to control the final microstructure and improve the electrical properties of (Ba, Sr)TiO3 films. I-V and C-V measurements show that (Ba, Sr)TiO3 films with a thickness of approximately 15nm can produce a charge storage density of >120 fF/μm2 with a leakage current density of < 10 nA/cm2 at IV, making them suitable for Gigabit-scale DRAM applications.
Microwave Tuning Quality and Power Handling of Voltage-Tunable Capacitors: Semiconductor Varactors Versus Ba1−xSrxTiO3 Films
Authors: Gait D. , Rivkina T. , Cromar M. W. 
Published: April 2011

ABSTRACTThin films of SrTiO3 and Ba0.4Sr0.6TiO3 have been pulse laser ablated onto LaAIO3 substrates. Normal metal coplanar capacitor electrodes were patterned on top of these films and the capacitors were incorporated into weakly coupled microstrip resonators. Resonant frequencies and Q's were measured as a function of bias at room temperature and at 77 K. The microwave frequency capacitance and loss is calculated from the resonant properties and compared with the simultaneously measured 1 MHz capacitance and dissipation. Two-tone intermodulation distortion products were measured and the third-order intercept is referenced to the microwave voltage across the capacitors. Commercially available semiconductor varactors were tested in a similar manner. The tuning quality (the ratio of the relative capacitance tuning to dissipation), frequency dispersion, and power handling of these capacitors are compared. Although there appears to be no intrinsic power handling advantage of the paraelectrics over the semiconductor varactors, the paraelectric varactors can offer better tuning quality.
Dielectric and Structural Properties of (100) KTa1−xNbxO3 Films Grown on MgO, LaAIO3 and SrTiO3 Substrates by Pulsed Laser Deposition
Authors: Chang Wontae , Carter Adriaan C. , Horwitz James S. , Kirchoefer Steven W. , Pond Jeffrey M. , Grabowski Kenneth S. , Chrisey Douglas B. 
Published: April 2011

ABSTRACTKTa1−xNbxO3 (KTN) thin films (-6000 Å) were grown on (100) MgO, (100) LaAlO3 (LAO), and (100) SrTiO3(STO) substrates by pulsed laser deposition (PLD). Deposited films were smooth, single phase and exclusively (100) oriented. KTN films deposited on MgO and LAO substrates were easily cracked after deposition or post deposition heat treatment. The film deformation appeared to be caused by strain due to the lattice mismatch between the film and the substrate. A thin buffer layer of ∼100 Å was used to eliminate the cracking problem. The high volatility of K at the film deposition temperature required excess K to be added to the ablation target. Sintering of the target and post-deposition annealing of the films were done in a sealed Pt coated stainless steel container. Rutherford backscattering showed the films to have a 1 to 1 atomic ratio of K to Ta + Nb. On top of the KTN films, Ag interdigitated capacitors were deposited. Room temperature measurements of capacitance and dielectric loss as a function of bias electric field (0 -80 kV/cm) at 1 to 20 GHz were made. Capacitance and dielectric loss measurements were made as a function of temperature and bias electric field at one MHz and as a function of temperature and frequency at 0V DC bias. The results show the strong potential of KTN for use in frequency agile microwave electronics.
Epitaxial lift-off of strontium titanate thin films and the temperature dependence of the low frequency dielectric properties of the films
Authors: Dalberth M. J. , Price J. C. , Rogers C. T. 
Published: April 2011

ABSTRACTUsing pulsed laser ablation, we have grown epitaxial bilayers of strontium titanate (STO) and yttrium barium copper oxide (YBCO) on lanthanum aluminate (LAO) and neodymium gallate (NGO) substrates. Using a selective acid etch, we have removed the YBCO from the middle of the bilayer and lifted off the strontium titanate films from their parent substrates. Using coplanar interdigital capacitors patterned on the films' surface, we have measured the dielectric constant and loss as a function of frequency and temperature and have resolved frequency dependent loss peaks which indicate thermally activated behavior. Also, by applying a dc bias to the capacitor, we have seen tuning of the lifted off films' dielectric constants that compares favorably to films attached to substrates.
The Growth of Nonlinear Optical Thin Films of KTa1−xNbxO3 on GaAs by Pulsed Laser Deposition for Integrated Optics
Authors: Knauss L. A. , Harshavardhan K. S. , Zhang H. Y. , He X. H. , Shih Y. H. , Grabowski K. S. , Knies D. L. 
Published: April 2011

ABSTRACTNonlinear optical films on GaAs and other III-V (AlGaAs, InGaAs) semiconducting substrates have many potential applications in integrated optics. Until now, the growth of device quality films on GaAs was a major technological challenge. Using Pulsed Laser Deposition (PLD) epitaxial films of prototypical nonlinear KTa0.52Nb0.48O3 (KTN) were successfully deposited on single crystalline GaAs substrates for the first time. In order to alleviate chemical and structural incompatibilities between the GaAs substrate and KTN film at the growth temperature (∼750°C), a novel buffer layer scheme consisting of epitaxial MgO and SrTiO3 buffer layers and a Si3Ni4 encapsulation of the substrate was successfully developed. To obtain films with the required stoichiometry, a segmented target geometry was used consisting of KTN and KNO3 targets. The high crystalline quality of KTN films on GaAs was established by detailed 4-circle x-ray diffraction studies. Rutherford Backscattering studies confirmed the composition of the films. Optical measurements have been carried out on epitaxial KTN films on GaAs. Using an Ar+ laser (457.9 nm) operating in the TEM00 mode, we have observed sharp and distinguishable TE and TM propagating modes in KTN films. The refractive index (n0) of the film at 488 nm is 2.275 which is close to the bulk value of 2.35.
Process Optimization for Piezoelectric Films and Coatings
Authors: Sayer M. , Zou L. , Leclerc B. , Lukacs M. , Olding T. , Schloss J. H. 
Published: April 2011

ABSTRACTThe dielectric and piezoelectric response of sol gel based films and composite coatings is affected by the choice of process, gel composition, thermal cycle, processing atmosphere and poling conditions. Important general factors for thin films are the crystallization kinetics and the effects of residual carbon, while a new dielectric technique allows poling methods to be evaluated.
Antiferroelectric Thin Films for Decoupling Capacitor and Microactuator Applications
Authors: Xu Baomin , Pai Neelesh G. , Moses Paul , Eric Cross L. 
Published: April 2011

ABSTRACTLanthanum-doped or niobium-doped lead zirconate titanate stannate antiferroelectric thin films with the thickness of about 0.4 μm have been prepared from acetic acid-based or 2-methoxyethanol-based sol-gel method. All the films have the maximum polarization larger than 30 μC/cm2 and show zero remanent polarization. By choosing appropriate compositions, we can make the films have “square” hysteresis loops with very sharp phase transition or “slanted” hysteresis loops with very small hysteresis. The properties that are important for decoupling capacitor and microactuator applications are characterized. For decoupling capacitor applications, films having square hysteresis loops with energy storage density of up to 7 J/cm3 can be made, which release more than half of their stored charge in 10 ns with a maximum current density of more than 9400 A/cm2. For microactuator applications, the films can either have a strain level of 0.32% with very small hysteresis or have a strain level of 0.42% with moderate hysteresis.
Direct Wafer Bonding and Layer Transfer: An Innovative way for the Integration of Ferroelectric Oxides into Silicon Technology
Authors: Alexe M. , Senz St. , Pignolet A. , Scott J. F. , Hesse D. , Gösele U. 
Published: April 2011

ABSTRACTAn innovative fabrication process of ferroelectric-semiconductor heterostructures based on direct wafer bonding has been demonstrated. Ferroelectric thin films of Bi4Ti3O12 (BiT) and Pb(Zr,Ti)O3 (PZT) were deposited on 3” Si wafers using chemical solution deposition (CSD) and subsequently crystallized by conventional and rapid thermal annealing. The films were then polished in order to reach a roughness and waviness suitable for bonding. They were then directly bonded to silicon wafers in a micro-cleanroom and annealed in air at temperatures ranging from 200°C to 500°C. Bonding energies up to 1.5 J/m2 have been achieved which is almost high enough to consider the two bonded wafers as a single body. Metal-Ferroelectric-Silicon (MFS) structures containing the ferroelectric-Si bonded interface were accomplished by polishing down and etching the handling wafer. The MFS structures were electrically characterized by capacitance-voltage (C-V) and charge-voltage (Q-V) measurements.
Nanoscale Investigation of Polarization Retention Loss in Ferroelectric Thin Films VIA Scanning Force Microscopy
Authors: Gruverman A. , Prakash S. A. , Aggarwal S. , Ramesh R. , Auciello O. , Tokumoto H. 
Published: April 2011

ABSTRACTScanning force microscopy (SFM) was applied to direct nanoscale investigation of the mechanism of retention loss in ferroelectric thin films. Experiments were conducted by performing local polarization reversal within an individual grain with subsequent imaging of a resulting domain structure at various time intervals. A conductive SFM tip was used for domain switching and imaging in the SFM piezoresponse mode.
Synthesis and photoresponse of rare earth doped phosphosilicates
Authors: Cao Z. , Lee B. I. , Samuels W. D. , Exarhos G. J. , Wang L. 
Published: April 2011

ABSTRACTPhosphate ceramics doped with Sm3+ and Tb3+ ions were synthesized through sol-gel process. Thin films of Tb3+ doped phosphosilicates were fabricated by spin coating of the phosphosilicate sols on SiOx/indium-tin-oxide/glass substrates. The gels synthesized by reaction of P2O5 with tetraethoxy silane (TEOS) were fired in air at a temperature range of 200°C – 900°C. The crystal structure was examined by x-ray diffractometry. Si5O(PO4)6 was the only crystalline phase. The fluorescence spectra of Sm3+ as a function of firing temperature, composition and structure of the matrices were investigated. The intensity of Sm3+ emission increased with increasing firing temperatures and greater proportion of phosphorus. The photocurrent of the films at 355 nm laser excitation was observed. The photoresponse as a function of laser energy was linear and showed no sign of saturation. The films exhibited stable photoresponse under a high number of laser shots.
Formation of Transparent SiO2 Thin Film at Room Temperature with Excimer Lamp Irradiation
Authors: Okamoto T. , Iizuka H. , Ito S. , Murahara M. 
Published: April 2011

ABSTRACTA transparent SiO2 thin film was grown with Xe2* excimer lamp and NF3, O2 mixed gases at room temperature. Unlike the conventional methods such as atomic layer epitaxy (ALE) at low temperature, this method requires only a few minutes for deposition without changing material gases. A Si substrate was placed in a reaction chamber, which was filled with NF3 and O2 gases. The gases were exposed to the Xe2* excimer lamp light, and SiF4 and NO2 were produced by photochemical reaction. The SiF4 was adsorbed on the substrate; which reacted with NO2 in gas ambient and was oxidized to form SiO2. The molecular layer was produced per reaction, and by voluntarily repeated reaction, the transparent SiO2 thin film was grown. As a result, the SiO2 film thickness of about 2200 Å was achieved for 15 minutes at room temperature. By annealing the formed SiO2 film, the surface current density of the formed SiO2 decreased; the higher the annealing temperature became, the more the surface density decreased.
Advanced Metal/Ceramic Catalysts for Hydrogen Generation by Steam Reforming of Hydrocarbons
Authors: Tikhov S. F. , Sadykov V. A. , Salanov A. N. , Potapov Yu. A. , Litvak G. S. , Tsybulya S. V. , Pavlova S. N. 
Published: April 2011

ABSTRACTThe main features of porous metal/ceramic catalysts for hydrocarbons steam reforming their formation via hydrothermal treatment of the powdered aluminum and lanthanum nickelate mixture in the confined space are elucidated. For catalysts obtained via this route, their polymodal pore structure was found to approach the optimum level. The phase composition of the active component precursor was shown to have a great impact on the specific catalytic activity of catalysts.
Reversible Hydrogen Uptake in Carbon-Based Materials
Authors: Brown S. D. M. , Dresselhaus G. , Dresselhaus M. S. 
Published: April 2011

ABSTRACTSeveral approaches for achieving reversible hydrogen uptake by carbon are considered, including intercalation, adsorption by a graphite surface, hydrogenation of fullerenes, and the filling of carbon nanotubes. Most scenarios suggest that it is difficult to achieve an atomic uptake [H/C] ratio exceeding unity. Evidence for H2 uptake by various carbon materials is reviewed.
Mixed Metal Phospho-Sulfates for Acid Catalysis
Authors: Thoma S. G. , Jackson N. B. , Nenoff T. M. , Maxwell R. S. 
Published: April 2011

ABSTRACTMixed Metal Phospho-Sulfates were prepared and evaluated for use as acid catalysts via 2-methyl-2-pentene isomerization and o-xylene isomerization. Particular members of this class of materials exhibit greater levels of activity than sulfated zirconia as well as lower rates and magnitudes of deactivation. 31P MAS NMR has been used to examine the role of phosphorous in contributing to the activity and deactivation behavior of these materials, while powder X-ray diffraction, BET surface area, IR, and elemental analysis were used to characterize the bulk catalysts.
A Novel TiO2 Film Catalyst — Preparation, Properties and Research on its Photocatalytic Oxidized Activity
Authors: Cao Y. A. , Zhang X. T. , CHONG L. Q. , WANG D. Y. , XIE T. F. , HUANG Y. , CUI Z. F. , SHI W. G. , LIU X. J. , WU Z. Y. , BAI Y. B. , LI T. J. , WU Y. 
Published: April 2011

ABSTRACTA new kind of TiO2 film catalyst was prepared by the Plasma-enhanced chemical vapor deposition (PECVD) method. The surface photovoltaic spectroscopy (SPS) results showed that its photoresponse was extended into the visible region. Photooxidation experiments showed that this kind of TiO2 film had high photocatalytic activity on degradation of phenol in aqueous solution. The influence of the thickness of TiO2 film on its photocatalytic activity was also discussed.
Theory of Electron Field Emission From Diamond And Diamond-Ldxe Carbon
Authors: Robertson J 
Published: April 2011

ABSTRACTIt is shown that the facile electron field emission from diamond and diamond-like carbon occurs because surface groups such as C-H can produce large changes in electron affinity, so that electric fields from the anode can be focused towards unhydrogenated surface areas of high affinity, the fields ending on negative charges in an underlying depletion layer. The resulting downwards band bending creates very large fields which cause Fowler-Nordheim emission, while not exceeding the material's breakdown field, which is the highest for any solid.
The Interaction of Carbon with the Diamond Surface: A Photoelectron Spectroscopy Study
Authors: Reinke P. , Wrase T. , Müller K. , Oelhafen P. , Locher R. 
Published: April 2011

ABSTRACTThe modification of the diamond surface through adsorbants offers the opportunity to adjust the electronic and electron emission properties of the surface. In the study presented here, we deposited between 0.1 and 100 monolayers of carbon from an electron beam evaporation source on polycrystalline diamond films. Photoelectron spectroscopy in the ultraviolet and X-ray regime was employed to characterize the surface. Observations on a (100) polycrystalline diamond film show, that the surface is first depleted of hydrogen and subsequent growth of an amorphous carbon film (a-C) occurs on the reconstructed surface. The deposition of these ultrathin carbon films allows the controlled introduction of sp2carbon and p-π states onto the diamond surface. The field emission current increases considerably with the amount of sp2-carbon accumulated at the diamond surface. The current-voltage characteristics only partially follow the Fowler-Nordheim equation, and the results obtained for different films are described and possible emission mechanism discussed.