bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nano-scale Interfacial Reactions of SrRuO3 Thin Film on Si (100) Substrate
Authors: Oh Sang Ho , Park Chan-Gyung 
Published: April 2011

ABSTRACTInterfacial reactions between SrRuO3 films and Si substrate were investigated by using field emission-transmission electron microscopy (FE-TEM). The compositional and structural variations across the interface were analyzed by using energy dispersive X-ray spectroscopy (EDS) and diffraction with an electron probe in 0.5 nm in diameter. Two constituent binary oxides of SrRuO3, i.e. SrO and RuO2, were found to react differently on Si surface: 1) SrO in stable contact with Si, and 2) RuO2 in unstable contact. The reduction of SrRuO3 to elemental Ru by Si is believed to be most favorable candidate for the reaction leading to the unstable contact of SrRuO3 on Si.
Substrate Influence on the Reversible and Irreversible Polarization Contributions in Ferroelectric Thin Films
Authors: Bolten Dierk , Böttger Ulrich , Rodriguez Julio , Lohse Oliver , Grossmann Michael , Schneller Theodor , Waser Rainer 
Published: April 2011

ABSTRACTIn this contribution, the influence of different substrates and textures on the reversible and irreversible polarization in Pb(Zr,Ti)O3 (PZT) thin films will be presented. One possible scenario to explain the origin of the ferroelectric hysteresis is the notion that the domain walls move through a potential generated by their interaction with randomly distributed defects of the matrix. This potential then gives rise to reversible and irreversible changes in the ferroelectric polarization. The exact features of the interaction potential also depend on the stress state of the material which can be influenced by a suitable choice of the substrate.To study the substrate influence, PZT thin films have been deposited on commercial Si wafers, MgO and SrTiO3 single crystals. Electrical characterization methods (hysteresis and small signal capacitance measurements) have been used to extract information on reversible and irreversible polarization contributions.
Self-Assembled 3-Mercaptopropyltrimethoxysilane (MPS) ON Ba0.5Sr0.5TiO3 as an Adhesion Layer for Microwave Devices
Authors: Cabrera Carlos R. , Warner Joseph D. , Mueller Carl H. , Keuls Fred Van , Miranda Félix A. , Tremont Rolando , Blasini Daniel , Morales Angel 
Published: April 2011

ABSTRACTThe use of self-assembled monolayers in patterning, adhesion studies, corrosion protection, and electronic devices is a growing research field. Here we discuss the use of (3-mercaptopropyl)trimethoxysilane (MPS) as an adhesion layer in microwave components using metal-ferroelectric thin film-dielectric heterostructures. The MPS has been used as an adhesion layer between a ferroelectric thin film and gold (Au) in the development of tunable microwave components. The system studied was the metal/ferroelectric thin film/dielectric heterostructure with the MPS molecule as an adhesion layer between the metal and the ferroelectric thin film. Specifically, we have looked at the interface between the Au layer and the Ba0.5Sr0.5TiO3 (BSTO) ferroelectric thin film deposited on LaAlO3 (LAO). Typically, during metallization via e-beam evaporation, it is common to deposit a chrome or titanium adhesion layer (∼ 15 nm thick) between the Au and BSTO films. However, this underlayer may diffuse through the Au causing an increase of the RF losses of the device. Replacing the metal buffer layer interface with a self-assembled structure, such as MPS, can avoid the effect of inter- diffusion of chrome in the Au vapor deposit film. The surface modification of Ba0.5Sr0.5TiO3 (BSTO) thin film with MPS was studied by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy. The effectiveness of MPS self-assembled monolayers as an adhesion layer was determined by analyzing the performance of Au/MPS/BSTO/LAO interdigital capacitors as a function of dc voltage and temperature at 1 MHz.
Near-field Scanning Optical Microscopy and Electron Microprobe Microscopy Investigations of Immiscibility Effects in Indium Gallium Phosphide Grown by Liquid Phase Epitaxy
Authors: Paulson C. A. , Ellis A. B. , Kuech T. F. 
Published: April 2011

ABSTRACTWe have used Near-field Scanning Optical Microscopy (NSOM) and Electron Probe Microanalysis (EPMA) to study the topographic and microscopic optical properties of indium gallium phosphide (In1−xGaxP) samples grown by Liquid Phase Epitaxy (LPE) on gallium arsenide substrates. Photoluminescence (PL) intensity images gathered using NSOM exhibit strong, highly localized variations in the optical properties of these samples that are seen to occur roughly in registry with the surface topography. Shifts in the PL peak position (by 27 meV) occur across highly mismatched samples with high In content, whereas no shifts were seen for In1−xGaxP films with a nearly lattice matched composition. Compositional fluctuations lead to these PL peak energy shifts, measured by NSOM with a resolution of 250 nm. These composition fluctuations arise from the known solid-solid miscibility gap in the In1−xGaxP system at temperatures used for the growth of these samples.
Amorphous Nitride Alloys as Hosts for Rare-Earth Luminescent Ions.
Authors: Caldwell M. L. , Little M. E. , Spalding C. M. , Kordesch M. E. , Richardson H. H. 
Published: April 2011

ABSTRACTAmorphous alloys of aluminum-gallium nitride doped with erbium (Er) were deposited at 300 K. The compositions ranged from 19% Al to 86% Al with optical band gaps varying linearly with composition from 3.4 eV (GaN) to 6.2 eV (AlN). The films were deposited on p-doped silicon (111) by a dc/rf dual gun system in a nitrogen/argon atmosphere at a pressure of 4.8 milli-Torr. After growth the films were thermally “activated” at 1070 K for 10 minutes in a nitrogen atmosphere. The cathodoluminescence emission intensities decreased linearly with Ga composition. This dependence suggests that the higher energy transitions in the Er ion are quenched by transitions to the conduction band of the alloys.
Luminescence of nanocrystalline ZnS:Pb2+
Authors: Bol Ageeth A. , Meijerink Andries 
Published: April 2011

ABSTRACTNanocrystalline ZnS:Pb2+ is synthesized via a precipitation method. The luminescence is studied and the influence of the size of the nanocrystals on the luminescence properties is investigated. Nanocrystalline ZnS:Pb2+ shows a white emission under UV excitation. At least two luminescence centers are involved. One center is identified as a Pb2+ ion located on a regular Zn2+ site and gives a red emission under 480 nm excitation. The luminescence properties of this emission are characteristic for transitions on Pb2+ ions. The other centers are not as well defined and give a broad green emission band under 380 nm excitation and also show luminescence properties typically observed for Pb2+. The green emission probably originates from a charge-transfer like D-band emission of Pb2+ in ZnS close to a defect (e.g. an S2− vacancy or an O2− ion on an S2− site). A relation between the temperature quenching of the emissions and the band gap is observed and indicates that photoionization occurs.
Pressure Tuning Spectroscopy of Mn2+ in Bulk and Nanocrystalline Sulfide Semiconductors
Authors: Smith Randy J. , Shen Yongrong , Bray Kevin L. 
Published: April 2011

ABSTRACTWe report the results of high pressure luminescence studies of the emission of Mn2+ in bulk Zn0.55Ga0.30S up to ∼214 kbar, bulk ZnS up to ∼184 kbar, and nanocrystalline ZnS (∼8 nm particle sizes) up to ∼300 kbar. We observed a strong redshift with pressure (-30(3) cm−1/kbar) for the 4T1→6A1 emission transition of Mn2+ in all three systems. We also observed emission quenching at high pressure in all three systems and attribute the quenching to a pressure induced phase change of the ZnS host lattice to a rocksalt (NaCl) phase.
Low-temperature technology and physical processes in green thin-film phosphor Zn2GeO4-Mn
Authors: Bondar V. , Popovich S. , Felter T. , Wager J. 
Published: April 2011

ABSTRACTThin-film Zn2GeO4:Mn phosphors with lower temperature of crystallization and potentially compatible with industrial technologies were investigated. The technology of thin films synthesis has been developed and their structure and crystal parameters have been investigated. Photoluminescence excitation spectra, photoconductivity, temperature dependencies and ESR-spectra of manganese ions were studied. A mechanism for luminescence in this phosphor has been proposed. Results are presented of cathodo- and electro-luminescence of thin film structures of Zn2GeO4:Mn.
Doping process issues for Sub-0.1 μm generation MOSFETs
Authors: Sugii Toshihiro , Pidin Sergey , Momiyama Youichi , Goto Ken- ichi , Tanaka Takuji , Yamamoto Tomonari , Futatugi Toshirou , Kase Masatak 
Published: April 2011

ABSTRACTTo meet the market demands for higher performance LSIs, traditional scaling has been aggressively pursued and has enjoyed great success over the 0.1-μm generations. To maintain continued growth of CMOS performance beyond the 0.1-μm generation, key issues originating from traditional scaling are addressed from the viewpoint of the doping processes (channel engineering, high-activation, and gate- electrode structure) in this paper.To meet the acceleration in gate-length miniaturization, short-channel effects must be suppressed at a low threshold voltage by using aggressive channel engineering. A channel-impurity profile must be optimized two-dimensionally, not uniformly or one-dimensionally. Channel engineering using tilted-channel implantation (TCI) with Indium is demonstrated.Traditional scaling results in large variations of threshold voltage due to the statistical-impurity variation in a channel region. We studied the effect of the above channel engineering on threshold voltage fluctuation caused by a statistical- dopant variation by measurement and simulation. It is reported that the two-dimensionally optimized channel profile enhances threshold-voltage fluctuation even if the implantation process variation is negligible.As CMOS device scales, reduction of parasitic resistance becomes very important for a high performance operation. Resistance at extension egde and contact resistance at silicide-Si interface are dominant factors.The traditional approach is to use a higher RTA temperature and a shorter RTA time. The ultimate RTA is laser annealing. We will demonstrate the laser annealing process with an ultra-low contact resistance of 4 × 10−8 Ω-cm2.By integrating the above technologies, ultra-thin gate insulators, and reduction in gate to source/drain overlap length, we can establish front-end process for sub-0.1 μm generations.
Diffusion of Implanted Nitrogen in Silicon at High Doses
Authors: Adam Lahir Shaik , Robertson Lance , Law Mark E. , Jones Kevin , Gable Kevin , Hegde Suri , Dokumaci Omer 
Published: April 2011

ABSTRACTNitrogen implantation is used to retard gate oxide growth thereby making it particularly usefulfor dual- VT and System On A chip technologies. This paper discusses the diffusion behavior and the concomitant defect evolution at high doses of implanted nitrogen in silicon. This paper shows that as the nitrogen implant dose is increased, the extent of nitrogen diffusion reduces. This paper also reports based onTEM studies, that upon annealing at 750°C, 5 × 10014 N2+/cm2, 40 keV implant produces Type I extended defects. However, 2 × 1015 N2+/cm2, 40 keV implant, produces a continuous amorphous layer to a depth ofabout 800 to 900 Å from the surface. In addition, upon annealing at 750°C, the 2 × 1015 N2+/cm2, 40 keV implant produces Type V or solid solubility defects in addition to End of Range or Type II defects.
Modeling of Boron Implantation Into Si With Decaborane Ions
Authors: Insepov Zinetulla , Sosnowski Marek , Yamada Isao 
Published: April 2011

ABSTRACTA molecular Dynamics (MD) model of B implantation into Si and of sputtering the Si surface withenergetic B10 clusters has been developed. The goal was to simulate the implantation of ions of decaborane (B10H14), which may become an important process for the formation of ultra shallow junctions in future MOS devices. The simulations, carried out for the cluster ion impact energy from 3.5 keV to 15 keV, have revealed the formation of a large amorphized region in a subsurface region. At low cluster impact energies in this range some of the B atoms were recoiled back from the surface, but at the energy of 12 keV and above almost all of the Boron atoms were successfully implanted into Si. The sputtering yield of Si has been also computed and found to increase with energy, reaching the value of 6 Si atoms per B10 cluster at 15 KeV. The number of displaced surface atoms correlates well with the sputtering yield, and between 3.5 and 10 keV it has a non-linear dependence on energy. At higher energies the number of displaced atoms increases linearly with energy, in agreement with the Khinchin-Pease formula [9]. The sputtering yield at 12 keV was also measured by the amount of Si removed by a decaborane beam from a thin Si film deposited on a carbon substrate. The predicted sputtering yield agrees well with this experiment.
Modeling of Annealing of High Concentration Arsenic Profiles
Authors: Fastenko Paevl , Dunham Scott T. , Henkelman Graeme 
Published: April 2011

ABSTRACTUnderstanding the diffusion and activation of arsenic is critical for the formation of low resistance ultra-shallow junctions as required for nanoscale MOS devices. In this work, we use results of ab-initio calcultions in order to gain insight into the fundamental process involved in arsenic activation/deactivation. Utilizing continuum modeling, we find it is possible to account for both the very rapid initial deactivation of arsenic as well as the strongly superline independence of interstitial supersaturation on doping level which accompanies deactivation. The critical process is the rearrangement of A s-atoms via in testitial mediated diffusion leading to ejection of silicon atoms from arsenic complexes and formation of arsenic-vacancy clusters.
Lattice site location of ultra-shallow implanted B in Si using ion beam analysis
Authors: Kobayashi Hajime , Nomachi Ichiro , Kusanagi Susumu , Nishiyama Fumitaka 
Published: April 2011

ABSTRACTWe have investigated the lattice site location of B in Si using ion channeling in combination with nuclear reaction analysis (NRA). Silicon samples implanted with Boron at an energy of 10 keV and a dose of 5 × 1014 cm−2 (low dose samples) or 5 × 1015 cm−2 (high dose samples) were annealed at 1000 °C for 10 seconds (RTA) or at 800 °C for 10 minutes (FA). The activation efficiencies of these samples were estimated from the B atomic concentration and the hole concentration obtained by secondary ion mass spectrometry (SIMS) and spreading resistance profiling (SRP), respectively. We also studied the ion implantation damage of Si crystals using ion channeling combined with Rutherford backscattering spectrometry (RBS). We found that the activation efficiency is proportional to the substitutionality, meaning that substitutional B is fully activated without any carrier compensation. We also found that B atoms go to the substitutional sites and are activated up to the solubility limit in the high dose samples. However, the ion implantation damage of the crystalline Si in the high dose samples increases somewhat after annealing.
Silicon Interstitial Driven Loss of Substitutional Carbon from SiGeC Structures
Authors: Carroll M. S. , Sturm J. C. , Napolitani E. , Salvador D. De , Berti M. , Stangl J. , Bauer G. , Tweet D. J. 
Published: April 2011

ABSTRACTThe effect of annealing silicon capped pseudomorphic Si0.7865Ge0.21C0.0035 or Si0.998C0.002 layers on silicon substrates in nitrogen or oxygen at 850°C was examined using x-ray diffraction (XRD) and secondary ion mass spectrometry (SIMS). Most substitutional carbon is lost from the alloy layers due to carbon out-diffusion rather than from precipitation. The carbon is found to diffuse more rapidly out of the SiGeC layer than the SiC layer after nitrogen and the carbon is found to leave the sample entirely, an effect that is enhanced by oxidation and thin cap layers. All substitutional carbon can be removed from the sample in some cases implying negligible formation of silicon-carbon complexes. Furthermore, it is found that each injected silicon interstitial atom due to oxidation causes the removal of one additional carbon atom for the SiGeC layer.
Rotational Averaging of Material Removal During CMP
Authors: Evans David R. , Oliver Michael R. 
Published: April 2011

ABSTRACTAt present, several different competing mechanical configurations are used in chemical mechanical polishing. These range from classical rotary designs to orbital and linear systems, as well as the more recent web format. Invariably, wafer rotation is used in all of these systems to average out gross material removal rates and improve within wafer thickness uniformity. Although this might appear to be trivial and unworthy of serious investigation, in reality the interaction of polishing pad surface structure, along with whatever abrasive particles and chemical agents that might be present is quite complex. In addition, fluid transport between wafer and pad surfaces is strongly affected by pad macrostructure and relative motion of the two surfaces.
Oxide Powders for Chemical Mechanical Polishing Produced by Chemical Vapor Synthesis
Authors: Sieger H. , Winterer M. , Keiderling U. , Hahn H. 
Published: April 2011

ABSTRACTUltrafine silica, alumina and doped alumina/silica powders have been produced by Chemical Vapor Synthesis (CVS). Primary particle sizes from 3.5 to 12.4 nm have been achieved. Agglomerate sizes ranging from approx. 10 to 150 nm have been achieved in aqueous dispersions.
Effects of Particle Concentration in CMP
Authors: Choi Wonseop , Lee Seung-Mahn , Singh Rajiv K. 
Published: April 2011

ABSTRACTThis paper reports on characterization of the surface coverage of particles by in-situ lateral friction force measurement during chemical mechanical polishing. The lateral friction force apparatus was made to operate close to real CMP conditions. For these experiments a sapphire wafer of constant surface roughness was used. For both 2psi and 4psi down force we observed increase in lateral friction forces with increasing solid loading. The lateral friction forces have been found to be significantly dependent on the contact area at the wafer-pad-slurry interface, thus showing that in-situ dynamic friction force changes in the surface coverage of particles. From these results, we conclude that the enhancement of frictional force is due to increased contact area at the wafer-pad-slurry interfaces. The lateral friction force measurement can provide an understanding of wafer-pad-slurry interactions.
Layout Pattern Density and Oxide Deposition Profile Effects on Dielectrics CMP
Authors: Park Young B. , Kim Joon Y. , Seo Dae W. 
Published: April 2011

ABSTRACTTest mask for characterizing pattern dependent variation of the remaining thickness after chemical-mechanical polishing (CMP) was designed with taking the experimentally obtained interaction distance into consideration. Measured interaction distance was constant independent of pattern variables such as pattern density and pattern shapes between line and area. And systematic exploration regarding pitch effects on remaining nitride thickness in STI (Shallow Trench Isolation) CMP was performed with comparing PETEOS (Plasma Enhanced Tetra Ethyl Ortho Silicate) and HDP (High Density Plasma) oxide. Both measured remaining nitride thickness and expected oxide pattern density from consideration of deposition profile effects showed a good correlation with respect to pitch variation for a constant layout pattern density.
Mechanisms of Post-CMP Cleaning
Authors: Liang H. , Estragnat E. , Lee J. 
Published: April 2011

ABSTRACTWe investigate the post-CMP cleaning process with a tribological approach. A cleaning process involves three components: brush, wafer/disk, fluid undergoing three-body sliding contact between the brush, wafer, and particles from slurry. Having this in mind, we investigated cleaning mechanisms through experimental measurement of friction force and analyzed the contact condition for particle removal. Our investigation leads to the conclusions that the cleaning process is a boundary to elastohydrodynamic lubricating process that involves a constant contact between a brush and the wafer or disk surface. The motion of the brush nodule is such that the surface forces between the brush and workpiece change from an initial adhesion to sliding abrasion. These analysis leads to insight of particle removal mechanisms.
Rapid adatom island decay on Cu(111): a kinetic Monte Carlo simulation study
Authors: Larsson Mats I. 
Published: April 2011

ABSTRACTKinetic Monte Carlo (KMC) simulations are used to investigate the recent scanning tunneling microscopy (STM) measurements of fast decaying adatom islands on Cu(111). The KMC model is a full diffusion bond-counting model including nearest neighbor as well as second-nearest neighbor interactions. For encounters between steps in adjacent atomic layers of an island it is demonstrated that a moderately reduced activation energy for interlayer adatom transport is enough to obtain correspondence between simulations and experiments, provided that the one-dimensional Ehrlich-Schwoebel barrier for corner transitions is reduced to zero. The results presented in this report are interesting because they demonstrate that step-edge crossing by simple adatom hopping is sufficient to explain the rapid island-decay mechanism.
Simulation Study of Copper Cluster Deposition
Authors: Kang Jin C. , Kang Jeong W. , Hwang Ho J. 
Published: April 2011

ABSTRACTThe ionized cluster beam deposition of Al and Cu clusters has been investigated with a classical molecular dynamics simulation and the Metropolis Monte Carlo simulation. The spreading of the cluster has been studied as functions of cluster size and initial cluster energy. When the local area reached local melting spot on the surface, around the impact point of an energetic cluster, during a few ps, intermixing was easily achieved and a good epitaxial film with optimum bulk density was formed. For uniform film growth using cluster impact, it is necessary to make the local area temperature higher than melting temperature on the surface around the impact point of an energetic cluster.
Crystallographic and morphological properties of magnetron sputtered Ti and Zr thin films
Authors: Chinaglia Eliane F. , Oppenheim Ivette C. 
Published: April 2011

ABSTRACTCrystallographic and surface morphological characteristics of polycrystalline hcp Ti and Zr thin films were studied as a function of the homologous substrate temperature TS/TM and the thickness t of the films (28 nm ≤ t ≤ 380 nm). TS is the substrate temperature during deposition and TM is the melting point of the film's material. For the whole range of considered temperatures (0.14 ≤ TS/TM ≤ 0.48) Zr films presented a {0002} crystallographic orientation. As TS/TM increased, Ti films suffered a transition from a columnar grain structure with {0002} preferential crystallographic orientation to a cone-like-shape grain structure with {1011} preferential crystallographic orientation. Our results suggest that Zr films suffer a structural transition from Zone T to Zone II at temperatures similar to those predicted by Thornton's Structure Zone Model for thick films while Ti films do not have a microstructure typical of Zone II even for relatively high values of TS/TM, presenting a transition from Zone I to Zone T in the studied range of temperatures.