bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Polarization Study of Ordered GaInP2
Authors: Zhang Yong , Ernst P. , Driessen F. A. J. M. , Mascarenhas A. , Geng C. , Scholz F. , Schweizer H. 
Published: April 2011

AbstractOptical polarization in ordered GaInP2 has been studied by low-temperature photoluminescence. By comparing our experimental results to the theoretical predictions, we show that to obtain quantitative information about ordering from the polarization of near-band-gap transitions, the effects of lattice mismatch, substrate misorientation, and excitonic transitions should be taken into account.
Ultra-low Contact Resistivity by High Concentration Germanium and Boron Ion Implantation Combined with Low Temperature Annealing
Authors: Murakoshi A. , Iwase M. , Koike M. , Niiyama H. , Suguro K. 
Published: April 2011

AbstractA new formation method for an ultra-low resistivity contact and structural analysis are discussed. In this study, a minimum contact resistivity of 6.9× 10−9 Ω·cm2 has been successfully obtained in an AlSi(lwt%)Cu(0.5wt%) alloy / Si system by using heavy dose ion implantations of Ge and B combined with low temperature annealing as low as 550°C. Structural analysis on the Si surface layer has been carried out. As a result, it was found that the crystal lattice was expanded in-plane by 6% in the Si layer near the surface because of the high concentration of Ge and no relaxation of lattice strain at such a low temperature. It was also found that super-saturation of B was stably formed in this system. An ultra-low resistivity contact is considered to be a result of these combined effects.
Current Issues and Future Trends in CMP Consumables for Oxide and Metal Polish
Authors: Moinpour M. , Philipossian A. 
Published: April 2011

IntroductionThe recent advent of Chemical Mechanical Planarization (CMP) as a major process technology has had a significant impact on the semiconductor industry. Oxide CMP is a technology enabler for logic and DRAM devices with feature sizes less than (or equal to) 0.75 micrometer [1]. Similarly, tungsten CMP has become a technology enabler for 0.35 micron devices [2,3], and current trends indicate that it will continue to play a major role in future generations of IC technologies [4,5]. CMP can also provide a technological advantage in front-end process modules such as Shallow Trench Isolation [6].
Optimization of PVD Ti/CVD TiN Liner for 0.35 μm Tungsten Plug Technology
Authors: Wang C.-K. , Liu L. M. , Liao D. M. , Smith D. C. , Danek M. 
Published: April 2011

AbstractA novel plasma enhanced CVD TiN process was integrated with high density plasma sputter etch preclean (PCII) and 1:1.5 collimated PVD Ti (c-PVD Ti) process to deposit a Ti/TiN liner for tungsten contact and via plugs. The integrated liner process was optimized for a 0.35 μm nonsalicide CMOS device application. RF power and sputter depth used for contact preclean were the major process variants affecting the contact resistance, junction leakage and transistor threshold voltage. Low contact resistance was obtained for a c-PVD Ti thickness of ∼375 Å. Via resistance was significantly lower with c-PVD Ti/CVD TiN liner as compared to only a TiN liner. Contact resistance for c-PVD Ti/c-PVD TiN and c-PVD Ti/CVD TiN liners were comparable while contacts with conventional PVD Ti/TiN liner showed significantly higher values due to poor step coverage. Low junction leakage current was obtained for integrated c- PVD Ti/CVD TiN stack.
Growth and Properties of W-Si-N Diffusion Barriers Deposited by Chemical Vapor Deposition
Authors: Fleming J. G. , Roherty-Osmun E. , Custer J. S. 
Published: April 2011

AbstractWe have used chemical vapor deposition to grow ternary tungsten based diffusion barriers to determine if they exhibit properties similar to those of sputter deposited ternaries. A range of different W-Si-N compositions were produced. The deposition temperature was low, 350°C, and the precursors used are accepted by the industry. Deposition rates are acceptable for a diffusion barrier application. Resistivities range from 350 to 20000 μΩ-cm, depending on composition. Step coverage of films with compositions expected to be of interest for diffusion barrier applications is 100%.
Electrical Characterization of Ultra-Shallow Junctions Formed by Diffusion From a CoSi2 Diffusion Source
Authors: Via F. La , Rimini E. 
Published: April 2011

AbstractUltra-Shallow p+/n and n+/p junctions were fabricated using a Silicide-As-Diffusion-Source (SADS) process and a low thermal budget (800÷900 °C). A thin layer (50 nm) of CoSi2 was implanted with As and BF2 and subsequently diffused at different temperatures and times to form two Ultra-Shallow junctions with a junction depth of 14 and 20 nm. These diodes were extensively investigated by I-V and C-V measurements in the range of temperature between 80 and 500 K. TEM delineation was used to controll the junction uniformity.
Amorphous Phase Formation of Titanium Silicide on The 4° off-Axis and on-Axis Si(100) Substrates
Authors: Jeon Hyeongtag , Lee Sukjae , Lee Hwackjoo , Ruh Hyun 
Published: April 2011

AbstractTwo different Si(100) substrates, the 4°off-axis and the on-axis Si(100), were prepared. Ti thin films were deposited in an e-beam evaporation system and the amorphous layers of Ti-silicide were formed at different annealing temperatures. The Si(100) substrates before Ti film deposition were examined with AFM to verify the atomic scale roughness of the initial Si substrates. The amorphous layer was observed by HRTEM and TEM. And the chemical analysis and phase identification were examined by AES and XRD. The Si(100) substrate after HF clean shows the atomic scale microroughness such as atomic steps and pits on the Si surface. The on-axis Si(100) substrate exhibits much rougher surface morphologies than those of the off-axis Si(100). These differences of atomic scale roughnesses of Si substrates result in the difference of the thicknesses of amorphous Ti-silicide layers. The amorphous layer thicknesses on the on-axis exhibit thicker than those of the off-axis Si(100) and these differences inamorphous layer thicknesses became decreased as annealing temperatures increased. These indicate that the role of the atomic scale roughness on the amorphous layer thickness is much significant at low temperatures. In this study, the correlation between the atomic scale roughness and the amorphous layer thickness is discussed in terms of the atomic steps and pits based on the observation with using analysis tools such as AFM, TEM and HRTEM.
Shallow and Low-Resistive Ohmic Contacts to p-In0.53Ga0. 47As Based on Pd/Au and Pd/Sb Metallizations
Authors: Ressel P. , Wang L. C. , Park M. H. , Leech P. W. , Reeves G. K. , Kuphal E. 
Published: April 2011

AbstractInP/In0.53Ga0.47As heterojunction bipolar transistors with high current gain for optoelectronic applications place stringent requirements on the ohmic contact to the base layer of moderately doped (p < 1×1019 cm−3) In0.53Ga0.47As. Contact resistivity should be <l×10−6 Ωcm2 and low depth of penetration is necessary considering the small base thickness of approximately 100 nm. The authors have recently presented data on Pd/Zn/Au/LaB6/Au contacts on p-In0.53Ga0.47As (doped to 4×1018 cm−3) with low contact resistivities of l×10−6 Ωcm2. In this paper, details are given on the optimization of the contact composition and annealing conditions of the metallization that resulted in shallow and low-resistive contacts. Alternatively, it is shown that Au-free Pd/Zn/Sb/Pd contacts on p-In0.53Ga0.47As have exhibited even lower resistivities, i.e. 3-6×10−7 Ωcm2. Backside SIMS measurements revealed a depth of penetration as low as 20 nm for this contact scheme. Aging tests at temperatures of 300 - 400 °C have demonstrated that the electrical characteristics of both types of metallization were sufficiently stable to withstand the typical processing steps for device passivation.
Growth and Engineering of Microporous Zeolite Films and Coatings
Authors: Yan Y. , Chaudhuri S. Ray. , Sarkar A. 
Published: April 2011

AbstractDeveloping very thin molecular sieve films (<lμm), required by many zeolite filmbased applications, has been found continually to be a technical challenge. The synthesis strategy of this work is to elucidate some of the parameters that influence the morphology, orientation, surface coverage density and thickness of Si-ZSM-5 films on supported substrates. Three different methods to grow zeolite coatings on fused silica have be studied and compared. The zeolite films have been characterized by field emission-SEM, XRD, sorption study and transmitting spectroscopy. At the early stage of crystal growth, the gel layer spontaneously condensed on the substrate surface may have a large porosity of 15%. The strong affinity to grow the (010) faces along the substrate surface is possibly responsible for the preferred orientation of the films. The conditions for synthesis of closely packed coatings, consisting of sub-micron crystals with preferred orientation, are also identified. Engineering issues for fabrication of low optical scattering zeolitic films will also be discussed for designing molecular sieve optical devices.
Gas Permeation and Microstructure of Silica Membranes Prepared Using an Organic Template Approach by Sol-Gel Processing
Authors: Cao G. Z. , Brinker C. J. 
Published: April 2011

AbstractThis paper investigates microporous amorphous silica membranes prepared using an organic template sol-gel approach. We find that the introduction of organic methacryloxypropyl ligands results in a reduced average condensation rate and a lower extent of branching that promotes the collapse of the hybrid network upon drying leading to relatively dense hybrid organic-inorganic xerogels and films. Microporous silica xerogels and membranes, prepared by oxidative pyrolysis of the organic templates at 300 °C for 5 hours in oxygen, contained pores with constrictions of approximately 0.35 nm in diameter with a very narrow size distribution, as evidenced by single gas permeation measurements of a series of probe molecules.
Gas Sensing Behavior of Porous ZnO Varistors Densified via Rate Controlled Sintering
Authors: Agarwal Gaurav , Speyer Robert F. 
Published: April 2011

AbstractA hydrogen gas sensor based on shift in breakdown voltage of a ZnO varistor was developed. Changes in rate controlled sintering schedules resulted in significant variations in microstructure. Microstructures showing more intergranular porosity and finer grain size demonstrated a comparatively more linear and broad response to H2 concentration. A mechanism for the shift in breakdown voltage based on adsorbed oxygen is suggested for this unique and potentially very useful sensor.
A Comparison of the Electrochemical Behavior of Carbon Aerogels and Activated Carbon Fiber Cloths
Authors: Tran T. D. , Alviso C. T. , Hulsey S. S. , Nielsen J. K. , Pekala R. W. 
Published: April 2011

AbstractThe electrochemical capacitative behavior of carbon aerogels and selected commercial carbon fiber cloths was studied in 5M potassium hydroxide, 3M sulfuric acid, and 0.5M tetraethylammonium tetrafluoroborate/propylene carbonate electrolytes. The resorcinolformaldehyde based carbon aerogels with a range of density (0.2–0.85 g/cc) have open-cell structures with ultrafine pore sizes (∼5–50 nm), high surface area (400–700 m2/g), and a solid matrix composed of interconnected particles or fibers with characteristic diameters of 10 nm. The commercial fiber cloths in the density range 0.2–0.4g/cc have high surface areas (1000–2500 m2/g). The volumetric capacitances of high-density aerogels are shown to be comparable to or exceeding those obtained from activated carbon fibers. The electrochemical behavior of these types of materials in various electrolytes is compared and related to their physical properties.
Electronic Doping in Porous Nano-Crystalline ZnO Films
Authors: Könenkamp R. , Wahi A. 
Published: April 2011

AbstractPorous nano-crystalline ZnO films were prepared in sol-gel technique, using spin coating and sintering at modest temperatures. The films consist of loosely-packed ZnO clusters. For films with clusters smaller than ∼ 50 Å we find a blue-shifted absorption edge indicative of quantum confinement in the clusters. The electronic properties of the films are largely controlled by surface processes. We have studied photo-induced conductance changes due to CO2 desorption using mass spectrometry and concomitant electrical measurements.
Nanofoam Porosity Measured by Infrared Spectroscopy and Refractive Index
Authors: Sanchez M. I. , Hedrick J. L. , Russell T. P. 
Published: April 2011

AbstractInfrared spectroscopy and optical waveguide were used to determine the porosity of polymer nanofoams produced from block copolymers of an aromatic polyimide endcapped with either poly(propylene oxide) or poly(a-methylstyrene). The infrared absorption bands and film thickness were compared to those of the neat homopolymer to yield an accurate measure of the void content. The porosity was also determined by measuring the refractive index and using the Maxwell-Garnett effective medium theory for spherical particles. Both techniques are in quantitative agreement with density gradient methods.
Nucleation and Growth of Fe(III)/PO4 Clusters
Authors: Rose J. , Flank A. M. , Manceau A. , Masion A. , Bottero J. Y. , Tchoubar D. , Garcia F. 
Published: April 2011

AbstractThe first stages of the hydrolysis of Fe(III) in presence of PO4 were studied at the local (P k-edge and Fe k-edge EXAFS spectroscopy) and semi-local scale (SAXS). The presence of PO4 hinders the polymerization of iron at the edge sharing dimer step. Phosphate probably governs the local structure leading to the formation of small and dense clusters. The fitting of both k-edge EXAFS spectroscopies requiered the use of a new 3D model of each nucleation step.
The Interaction of Liquid and Vapor Water with Nearly Defect-Free and Defective TiO2(100) Surfaces
Authors: Wang Li-Qiong , Skiba P. X. , Shultz A. N. , Baer Don R. , Engelhard Mark H. 
Published: April 2011

AbstractThe interaction of both liquid and vapor water on nearly defect-free and defective TiO2(100) surfaces has been investigated using X-ray photoelectron spectroscopy (XPS) and ultraviolet photoemission spectroscopy (UPS). The study has focused on examining electronic or chemical defects as created in vacuum and after exposure to both liquid and vapor water. Defective surfaces were prepared by electron-beam exposure and Ar+ bombardment. For a nearly defect-free (100)1×1 surface, water coverage was ∼0.02 ML (1ML = 2.9×1015/cm2) at 104 L exposure to low vapor pressure water, ∼0.08 ML at 108 L exposure to higher vapor pressure water, and ∼0.12 ML with liquid water exposure, respectively. Defect intensities were greatly reduced after exposing defective surfaces to ∼102 L low vapor pressure water. More significantly, electron-beam induced defects were completely removed upon higher-pressure vapor exposure (>104 L) or liquid water exposure, while defects created by Ar+ bombardment were only partially removed. The adsorption behavior and surface defect reactivity for TiO2(100) 1×1 surfaces were compared with those for TiO2(110) surfaces. The adsorption rates for nearly defect-free (100) 1×1 and (110) surfaces are comparable. However, the rate of defect “healing” for a defective (100) surface is much faster than that for a defective (110) surface.
Rf Magnetron Sputter-Deposition of La0.5Sr0.5CoO3//Pt Composite Electrodes for Pb(Zr, Ti)O3 Thin Film Capacitors
Authors: Raymond M. V. , Al-Shareef H. N. , Tuttle B. A. , DiMos D. , Evans J. T. 
Published: April 2011

AbstractLa0.5Sr0.5CoO3 (LSCO) thin films have been deposited using RF magnetron sputterdeposition for use as an electrode material for Pb(Zr, Ti)O3 (PZT) thin film capacitors. The effect of the O2:Ar sputter gas ratio during deposition, on the LSCO film properties was investigated. It was found that the resistivity of the LSCO films deposited at ambient temperature decreases as the O2:Ar ratio was increased for both the as-deposited and annealed films. In addition, it was found that thin overlayers of LSCO tend to stabilize the underlying Pt//Ti electrode structure during subsequent thermal processing. The LSCO//Pt//Ti composite electrode stack has a low resistivity and provides excellent fatigue performance for PZT capacitors. Furthermore, the LSCO//Pt//Ti electrode sheet resistance does not degrade with annealing temperature and the electrode does not display hillock formation. Possible mechanisms for the stabilization of the Pt//Ti electrode with LSCO overlayers will be discussed.
Microstructure of Pulsed-Laser Deposited Pzt on Polished and Annealed Mgo Substrates
Authors: King Simon L. , Coccia Luigi G. , Gardeniers J.G.E. , Boyd Ian W. 
Published: April 2011

AbstractThin films of Lead-Zirconate-Titanate (PZT) have been grown by pulsed-laserdeposition (PLD) onto polished MgO substrates both with and without pre-annealing.The surface morphology of polished MgO substrates, which are widely used for deposition, is examined by AFM. Commercially available, mechanically-polished substrates are shown to be microscopically very rough and seem unlikely to present a surface suitable for the growth of the highest quality thin films. Annealed MgO substrates, on the other hand, comprise atomically flat terraces. The use of annealed substrates is found to enhance considerably the crystalline quality of PZT films deposited thereon.
Microstructural Characterization of Pt/Ti and RuO2 Electrodes on SiO2/Si Annealed in the Oxygen Ambient
Authors: Lee Jeong Soo , Kwon Hyun JA , Jeong Young Woo , Kim Hyun HA , Park Kyu HO , Kim Cha Yeon 
Published: April 2011

AbstractMicrostructures and interdiffusions of Pt/Ti/SiO2/Si and RuO2/SiO2/Si during annealing in O2 were investigated using x-ray diffraction, Auger electron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The degree of oxidation and the interdiffusion of elements have remarkably increased with increasing temperature above 500 °C for the Pt/Ti/SiO2/Si case. The generation of Pt hillocks commenced at 500 °C. The Pt-silicide phase was also observed near the TiOx/SiO2 interface. The microstructural variations occurred to only a small amount for the RuO2/SiO2/Si case over the temperature range 300 – 700 °C. While there was no hillock formation, the RuO2 film surface was roughened by the thermal grooving phenomenon. A thin interlayer phase was found at the RuO2/SiO2 interface.
Defects and Electronic Transport in Rare Earth Doped Epitaxial SrTiO3 Thin Films
Authors: Gilbert S.R. , Wessels B.W. , Brazis P.W. , Hogan T.P. , Kannewurf C.R. 
Published: April 2011

AbstractSemiconducting, epitaxial SrTiO3 thin films doped with Eu3+ donors were analyzed using transient photocapacitance spectroscopy to determine the nature of the charge compensating defects. Deep level defects were detected with optical thresholds at Ec - 0.6 eV, Ec - 0.8 eV, and Ec - 2.05 eV. The level at Ec - 0.8 eV was the dominant defect in all of the films examined, with concentrations ranging from 1.6×1015 to 1.2×1017 cm−3 that increased as the square of donor concentration. The level was attributed to the strontium vacancy.
Microstructural Characterisation of Pb(Zr0.52Ti0.48)O3 Thin Films Deposited on RuO2 Electrodes by Laser Ablation
Authors: Benedittis A De , Cristoforo A. Di , Mengucci P. , Majni G. , Diodati A. , Leccabue F. , Watts B.E. , Seuret D. , Smeets J. 
Published: April 2011

AbstractAn aspect which has hindered the development of ferroelectric memories is dielectric fatigue and to resolve this conducting oxides are promising candidates as an electrode material for lead zirconate titanate thin films. In this work ferroelectric films have been grown by pulsed laser deposition on ruthenium oxide electrodes. The phase distribution, microstructure and the effect of subsequent heat treatment have been studied by grazing angle X ray diffraction and electron microscopy; the results and implications for use of RuO2 as the bottom electrode during vapour phase deposition are discussed.
Low Temperature Fabrication of (Ba, Sr)TiO3 Thin Films by ECR Plasma CVD
Authors: Kato Y. , Yabuta H. , Sone S. , Yamaguchi H. , Iizuka T. , Yamamichi S. , Lesaicherre P-Y. , Nishimoto S. , Yoshida M. 
Published: April 2011

AbstractPhysical and electrical properties are investigated for (Ba, Sr)TiO3 (BST) films prepared by electron cyclotron resonance (ECR) plasma chemical vapor deposition (CVD) at relatively low temperatures, between 450 °C and 500 °C. The crystallinity of BST, estimated by X-ray diffraction and from the grain size, is greatly improved when the temperature is raised from 450 °C to 500 °C. Also better crystallinity is obtained for films grown at a deposition rate of 1.1 nn/min than at 2.7 nm/min. The mass transport rates of metal organic sources under our deposition conditions are estimated. The BST film composition is precisely controlled using the results of the investigation on mass transport. At near stoichiometric composition, i.e., (Ba+Sr)/Ti=0.97, and Ba/(Ba+Sr)=0.4, the films grown at 500 °C are found to have the largest dielectric constant, measured using flat capacitors with Pt bottom electrodes. A dielectric constant of 160 is obtained for 27 nm thick films grown at 500 °C and at 1.1 nm/min, without post-deposition annealing. These films exhibit the smallest SiO2 equivalent thickness of 0.65 nm and a leakage current density of 4.6x10−7 A/cm2 at plus IV.
Thickness-Dependent Electrical Properties in Lanthanum-Doped Pzt Thick Films
Authors: Chen H.D. , Li K.K. , Gaskey C.J. , Cross L.E. 
Published: April 2011

AbstractLanthanum-doped lead zirconate titanate (PLZT) films, with thickness up to 10 μm, are fabricated on platinized silicon substrates through a modified sol-gel technique. Thicknessdependent piezoelectric properties measured with a double-beam laser interferometer show piezoelectric relaxation in field-induced strain as the ac driving field exceeds 10 kV/cm. In addition, the strain levels of PLZT thick films are approximately one third of those of undoped PZT films under the same fabrication and measurement conditions. For 1 μm PZT(55/45) films doped with 0, 2, and 4 mole% La, the P-E hysteresis exhibits decreasing squareness with increasing lanthanum content while the piezoelectric d33 coefficient reduces from 130 to 52 pC/N. Residual (tensile) stress in these films and resulted depoling effect may be responsible for this phenomenon.
Interfacial Diffusion Effects and Non-Stability of Disperse Layered Structures
Authors: Paritskaya L. N. , Bogdanov V. V. 
Published: April 2011

AbstractThe kinetics and atomic mechanism of the low temperature phase formation and accompanying effects in disperse multilayered structures of the binary systems Ni – Cr and Ni – Al have been studied under the conditions when volume diffusion is practically “frozen”.
An Analysis of Ductile Brittle Fracture Transition in Layered Composites
Authors: Biner S. B. 
Published: April 2011

AbstractIn this study the failure of the ductile layers in laminated composite systems was studied numerically. The results indicate that similar maximum stress values develop in the ductile layers as in the fracture test of the same ductile material if the crack tip in the brittle layer is already at the interface. For nondebonding interfaces brittle behavior of the ductile layers is dependent upon the extent of the cracks and the fracture characteristic of the brittle layers.