bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Integration of Interlayer Dielectric Deposition and Chemical
Mechanical Polishing
Authors: McAfee Anda , Koos Daniel A. , mcArdle Stephen , Jacobs Mercedes , Hiatt Robert 
Published: April 2011

ABSTRACTThis paper addresses an important process issue in tie integration of
chemical mechanical polishing (CMP) with interlayer dielectric (ILD)
deposition for advanced back end processing. Gap fill between metal lines is
achieved by using a dep-etch-dep technique for the tetraethylorthosilicate
(TEOS) ILD deposition. The ILD layer is then planarized by CMP. Vias are
etched through the ILD and filled with tungsten plugs in a blanket tungsten
deposition and tungsten CMP sequence. Delamination has been observed at the
interface between the TEOS layers following the blanket tungsten deposition
and before or during tungsten CMP. The weak interface between the TEOS
layers was found to be the result of residual carbon and fluorine from the
tetraflouromethane (CF4) doped etch process. The interface between the TEOS
layers was examined using X-ray photoelectron spectroscopy (XPS) and atomic
force microscopy (AFM). Experiments were carried out to determine if the
residue and subsequent delamination could be eliminated by modifying the
dep-etch-dep process. An improved process was identified and has been
implemented on a 0.5μm CMOS and mixed-mode BiCMOS production line with no
subsequent occurrence of interfacial delamination.
‘Back end’ Chemical Cleaning in integrated Circuit Fabrication:
a Tutorial
Authors: Obeng Yaw S. , Raghavan R. S. 
Published: April 2011

ABSTRACTThe applications of wet chemical cleaning at the ‘back-end’ of Integrated
Circuit (IC) or Metal-Oxide Semiconductor (MOS) fabrication are reviewed
from chemical, environmental and cost perspectives. The various classes of
commercially available “solvents” and “cryogenic” cleans are reviewed from
the perspective of process suitability, impact on device yield and waste
management. Strategies for minimizing processing concerns, as well as
alternatives to organic solvent based wet chemical processing will also be
discussed. Bulk photoresist (PR) stripping, post metal definition-, and post
window etch cleaning are used to illustrate the discussion.The use of radiotracing as a diagnostic tool in understanding the mechanism
for metallic contamination during solvent cleans is also discussed. Data
suggesting how the chemistry and solvent composition affects alkali metal
(for example, sodium) contamination of dielectric- and barrier films during
IC processing will also be presented.
Minimization of Interfacial Microroughness for 13–60 Å Ultrathin
Gate Oxides
Authors: Sapjeta J. , Boone T. , Rosamilia J. M. , Silverman P. J. , Sorsch T. W. , Timp G. , Weir B. E. 
Published: April 2011

ABSTRACTBy using a combination of smooth epi substrates (0.7 Å rms roughness),
in-situ UV/Cl2 processing, and rapid thermal oxidation, highly
reliable ultrathin gate oxides were produced with ≤ 1.0 Å rms interface
roughness.
Investigation of the Need for Alternative cleaning Chemistries for 30Å Gate Oxides
Authors: Bayoumi Amr , Fischer-Colbrie Alice , Parker Russ , Cox Mike , Greene Wayne 
Published: April 2011

ABSTRACTA comparative study of pregate cleaning solution chemistries has been conducted, for 30Å furnace oxides, to investigate the feasibility of continuing to use current cleaning technologies in this thickness range. The experiment focused on correlating changes of device properties with changes in chemistry. Several options were investigated for growing or etching the surface passivation oxide. Chemistries studied included standard SC1 (with Megasonic)/SC2, final HF, as well as room temperature single bath HF based chemistries (HF only, HF+H2O2, HF+HCl, HF+H2O2+HCl, SPM+HF). These chemistries were evaluated in terms of oxidation rate, metallic contamination from solutions, capacitance-voltage (CV) characteristics, and gate oxide integrity. Data suggest that furnace oxides can be reliably grown using conventional cleaning technology. HF-based mixtures might be justified for even more aggressive gate oxide thicknesses.
Analysis of Organic Contamination in Gases using Non-Volatile
Residue (NVR) Monitors and Time-of-Flight Secondary Ion Mass Spectrometry
(Tof-Sims)
Authors: Strossman G. S. , Lindley P. M. , Bowers W. D. 
Published: April 2011

ABSTRACTA methodology has been developed which provides a means of detecting and
chemically characterizing low levels of contaminants in process gases used
in the microelectronics industry. NVR monitors based on SAW (surface
acoustical wave) technology were exposed to cylinders of a common gas used
in microelectronics applications. A control cylinder of clean N2
was compared with a deliberately contaminated cylinder and two supposedly
clean cylinders from different suppliers. The SAW devices were able to
detect the residue deposited from each gas. After exposure to the cylinders,
the SAW devices were directly analyzed by time-of-flight secondary ion mass
spectrometry (TOF-SIMS) to identify the deposited residues. The TOF-SIMS
instrument was equipped with a liquid-N2 cooled sample stage to
facilitate detection of semivolatile species in the UHV environment
necessary for the analysis.
Effect of Sheet Electron-Beam Irradiation (SEBI) on Water
Wettability of Mirror-Finished Si Wafer
Authors: Mori K. , Okada T. , Oguri K. , Nishi Y. 
Published: April 2011

ABSTRACTThe influence of sheet electron beam irradiation ( SEBI ) on the
water-wettability of the ( 100 ) plane on the Si wafer etched by
hydrofluoric acid ( HF ) is investigated. The wettability energy is
estimated from the contact angle of water. The SEBI treatment decreases the
contact angle and increases the interfacial energy. Aging decreases the
change in the interfacial energy. A rate process is inferred for the
interfacial energy changes on the Si wafer.
Cleaning Process Optimization in a Gate Oxide Cluster Tool Using
an in-Line XPS Module
Authors: Froeschle Barbara , Glowacki Frédérique , Bauer Anton J. , Kasko Igor , Oechsner Richard , Schneider Claus 
Published: April 2011

ABSTRACTA cleaning process using anhydrous HF (AHF)/methanol and ozone was carried
out in a STEAG AST Vapor Phase Cleaning module (VPC). This module was
integrated in a state-of-theart cluster tool also consisting of a STEAG AST
Rapid Thermal Oxidation module (RTO). To investigate the properties of
silicon after cleaning a novel in-line XPS module was integrated into the
gate oxide cluster. Measurements of fluorine, carbon, and oxygen
contamination in the range from 0.01 to 1 monolayers on cleaned wafer
surfaces and on regrown oxides (< 0.5 nm) have been performed and used
for rapid optimization of the cleaning procedure. The in-line integration
enabled measurements without exposing the wafers to atmosphere thus avoiding
oxidation or contamination of the wafer surfaces. To demonstrate the
feasibility of this cluster tool for advanced gate dielectric formation, 4.0
nm thin oxide was grown directly after the cleaning in the RTO module
without breaking the vacuum. Time dependent dielectric breakdown results for
oxides pre-oxidation-cleaned in AHF, and in AHF followed by ozone were
compared to a reference sample without any dry pre-oxidation cleaning. It
could be shown, that the cleaning in AHF with a subsequent ozone step at
200°C under UV light lead to improved breakdown characteristics compared to
AHF/methanol cleanings without such subsequent ozone/UV step or conventional
wet cleaning using HF-Dip.
Silicon Surface Metal Contamination Measurements using
Grazing-Emission XRF Spectrometry
Authors: De Gendt S. , Kenis K. , Baeyens M. , Mertens P. W. , Heyns M. M. , Wiener G. , Kidd S. J. , Knotter D. M. , De Bokx P. K. 
Published: April 2011

ABSTRACTGrazing-Emission X-Ray Fluorescence Spectrometry (GEXRF) is a new analytical
X-ray fluorescence technique, which like TXRF takes advantage of the
total-reflection phenomenon. The main advantage of GEXRF over TXRF is its
sensitivity towards light elements. This paper presents straight GEXRF and
VPD-DC-GEXRF analysis results for Na, Mg, Al, K and Ca surface contamination
on silicon wafers.
Ozone Cleaning of Carbon-related Contaminants on Si Wafers and
other Substrate Materials
Authors: Nonaka H. , Kurokawa A. , Ichimura S. , Moon D. W. 
Published: April 2011

ABSTRACTWe have investigated a novel surface cleaning technique of native oxide on
Si wafer, in which carbon-related contaminants are removed effectively at
room temperature with a pure ozone beam from an ozone jet generator that we
developed. Although ozone alone was likely to be little reactive to
saturated carbons and byproducts in the reaction of ozone with unsaturated
carbons which could be assigned to either carbonyl- or carboxyl-related
compounds, a high-dose pure ozone under ultraviolet light irradiation to
generate atomic oxygen by the photo-dissociation of ozone removed most of
them at room temperature. The effectiveness of the ozone cleaning was also
demonstrated for selected oxide surfaces.
Thermal Conductivity of Zn4−xCdxSb3 Solid Solutions
Authors: Caillat T. , Borshchevsky A. , Fleurial J. -P. 
Published: April 2011

Abstractβ-Zn4Sb3 was recently identified at the Jet Propulsion Laboratory as a new high performance p-type thermoelectric material with a maximum dimensionless thermoelectric figure of merit ZT of 1.4 at a temperature of 673K. A usual approach, used for many state-of-the-art thermoelectric materials, to further improve ZT values is to alloy β-Zn4Sb3 with isostructural compounds because of the expected decrease in lattice thermal conductivity. We have grown Zn4−xCdxSb3 crystals with 0.2≤x<1.2 and measured their thermal conductivity from 10 to 500K. The thermal conductivity values of Zn4−xCdxSb3 alloys are significantly lower than those measured for β-Zn4Sb3 and are comparable to its calculated minimum thermal conductivity. A strong atomic disorder is believed to be primarily at the origin of the very low thermal conductivity of these materials which are also fairly good electrical conductors and are therefore excellent candidates for thermoelectric applications.
Selection and Evaluation of Materials for Thermoelectric Applications II
Authors: Sharp Jeff W. 
Published: April 2011

AbstractIn good thermoelectrics phonons have short mean free paths, and charge carriers have long ones. The other requirements are a multivalley band structure and a band gap greater than 0.1 eV for the 200 to 300 K temperature range. We discuss the use of solid state physics and chemistry concepts, along with atomic and crystal structure data, to select the new materials most likely to meet these criteria.
Quantum Confinement Effects on the Thermoelectric Figure of Merit in Si/Si1−xGex System
Authors: Sun X. , Dresselhaus M. S. , Wang K. L. , Tanner M. O. 
Published: April 2011

AbstractThe Si/Sil−xGex quantum well system is attractive for high temperature thermoelectric applications and for demonstration of proof-of-principle for enhanced thermoelectric figure of merit Z, since the interfaces and carrier densities can be well controlled in this system. We report here theoretical calculations for Z in this system, and results from theoretical modeling of quantum confinement effects in the presence of δ-doping within the barrier layers. The δ-doping layers are introduced by growing very thin layers of wide band gap materials within the barrier layers in order to increase the effective barrier height within the barriers and thereby reduce the barrier width necessary for the quantum confinement of carriers within the quantum well. The overall figure of merit is thereby enhanced due to the reduced barrier width and hence reduced thermal conductivity, K. The δ-doping should further reduce K in the barriers by introducing phonon scattering centers within the barrier region. The temperature dependence of Z for Si quantum wells is also discussed.
Experimental Transport Phenomena and Optimization Strategies for Thermoelectrics
Authors: Ehrlich A. C. , Gillespie D. J. 
Published: April 2011

AbstractWhen a new and promising thermoelectric material is discovered, an effort is undertaken to improve its “figure of merit”. If the effort is to be more efficient than one of trial and error with perhaps some “rule of thumb guidance” then it is important to be able to make the connection between experimental data and the underlying material characteristics, electronic and phononic, that influence the figure of merit. Transport and fermiology experimental data can be used to evaluate these material characteristics and thus establish trends as a function of some controllable parameter, such as composition. In this paper some of the generic-materials characteristics, generally believed to be required for a high figure of merit, will be discussed in terms of the experimental approach to their evaluation and optimization. Transport and fermiology experiments will be emphasized and both will be outlined in what they can reveal and what can be obscured by the simplifying assumptions generally used in their interpretation.
Analysis of Grain Boundaries, Twin Boundaries and Te Precipitates in Cd1−xZnxTe Grown by High-Pressure Bridgman Method
Authors: Heffelfinger J. R. , Medlin D. L. , James R. B. 
Published: April 2011

AbstractGtain boundaries and twin boundaries in commercial Cd1−xZnxTe, which is prepared by a high-pressure Bridgeman technique, have been investigated with transmission electron microscopy, scanning electron microscopy, infrared-light microscopy and visible-light microscopy. Boundaries inside these materials were found to be decorated with Te precipitates. The shape and local density of the precipitates were found to depend on the particular boundary. For precipitates that decorate grain boundaries, their microstructure was found to consist of a single, saucer-shaped grain of hexagonal Te (space group P3,2 1). Analysis of a Te precipate by selected-area diffraction revealed the Te to be aligned with the surrounding Cd1−xZnxTe grains. This alignment was found to match the (111) Cd1−xZxTe planes with the (0 111) planes of hexagonal Te. Crystallographic alignments between the Cd1−xZnxTe grains were also observed for a high-angle grain boundary. The structures of the grain boundaries and the Te/Cd1−xZnxTe interface are discussed.
Growth and Characterization of PbSe and Pb1−xSnxSe Layers on Si (100)
Authors: Sachar H. K. , Chao I. , Fang X. M. , Mccann P. J. 
Published: April 2011

AbstractCrack-free layers of PbSe were grown on Si (100) by a combination of liquid phase epitaxy (LPE) and molecular beam epitaxy (MBE) techniques. The PbSe layer was grown by LPE on Si (100) using a MBE-grown PbSe/BaF2/CaF2 buffer layer structure. Pb1−xSnxSe layers with tin contents in the liquid growth solution equal to 3%, 5%, 6%, 7%, and 10%, respectively, were also grown by LPE on Si (100) substrates using similar buffer layer structures. The LPE-grown PbSe and Pb1−xSnxSe layers were characterized by optical Nomarski microscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Optical Nomarski characterization of the layers revealed their excellent surface morphologies and good growth solution wipe-offs. FTIR transmission experimentsshowed that the absorption edge of the Pb1−xSnxSe layers shifted to lower energies with increasing tin contents. The PbSe epilayers were also lifted-off from the Si substrate by dissolving the MBE-grown BaF2 buffer layer. SEM micrographs of the cleaved edges revealed that the lifted-off layers formed structures suitable for laser fabrication.
Nonmonotonous Behavior of Temperature-Dependence of Plasma Frequency and Effect of a Local Instability of the PbTe:In,Ga Lattice
Authors: Belogorokihov A. I. , Belogorokhova L. I. , Khokhlov D. R. 
Published: April 2011

AbstractThe optical spectra of PbTe:In,Ga samples were studied in the Far Infrared region at temperatures T=11 K–3 50K. Anomalous behavior of the temperature dependence of the plasma frequency at 65K–80K was observed for the first time. This is explained by means of a model of localized changes in the lead telluride lattice structure near impurity centers.
The Effect of Tensile Strain on AlGaAs/GaAsP Interdiffused Quantum Well Laser
Authors: Chan K. S. , Chan Michael C. Y. 
Published: April 2011

AbstractIn this paper, we study the interdiffusion of tensile strained GaAsyPi.y /A10 33Ga0 67As single QW structures with a well width of 60Å. Different P concentrations in the as-grown well are chosen to obtain different tensile strains in the QW. Interdiffusion induces changes in the tensile strains and confinement potentials, which consequently change the valence band structure and the optical gain.
Polarized Raman Scattering Study of ZnGeP2 Single Crystals
Authors: Tlali Spirit , Jackson Howard E. , Ohmer M. C. , Schunemann P. G. , Pollak T. M. 
Published: April 2011

AbstractRaman scattering experiments on high quality ZnGeP2 single crystals grown by the seeded horizontal dynamic gradient technique have been carried out. Polarized Raman spectra were obtained in the backscattering geometry at both room and low temperatures for several crystal orientations and compared with group theoretical predictions. Raman spectra from as-grown and annealed samples display distinctive differences which were explored by utilizing two different excitation wavelengths: 514.3 nm and 632.8 nm; the observed differences are attributed to a surface interdiffuasion effect.
Relaxed Inx.Ga1−xas Graded Buffers Grown With Organometallic Vapor Phase Epitaxy on GaAs
Authors: Bulsara M. T. , Leitz C. , Fitzgerald E. A. 
Published: April 2011

AbstractInxGa1−xAs structures with compositionally graded buffers were grown with organometallic vapor phase epitaxy (OMVPE) on GaAs substrates and characterized with plan-view and cross-sectional transmission electron microscopy (PV-TEM and X-TEM), atomic force microscopy (AFM), and x-ray diffraction (XRD). The results show that surface roughness experiences a maximum at growth temperatures where phase separation occurs in In.Gal.,As. The strain fields from misfit dislocations induce this phase separation in the <110> directions. At growth temperatures above and below this temperature, the surface roughness decreases significantly; however, only growth temperatures above this regime ensure nearly complete relaxed graded buffers with the most uniform composition caps. With the optimum growth temperature for grading InxGa1−x,As determined to be 700 °C, it was possible to produce In0.33Ga0.67As diodes on GaAs with threading dislocation densities < 8.5 × 106/cm2.
Gamma Ray Spectrometers Fabricated from Modified Bridgman/Annealed CZT Crystal Material
Authors: Chattopadhyay K. , Chen H. , Chen K-T. , Burger Arnold , Flint J. P. , Glass H. L. , James R. B. 
Published: April 2011

AbstractThe CZT boule was grown by a modified vertical Bridgman process using in-situ compounding, Cd over-pressure and a pyrolytic boron nitride crucible within a fused ampoule. During growth, the Cd vapor pressure was near 1 atmosphere. These growth conditions tend to give high purity, good stoichiometry, few precipitates, and dislocation densities in the low to mid-104 cm−2 range. The crystals, after polishing, were annealed in a nearly saturated Cd, Zn atmosphere to fill residual Cd-site vacancies and achieve high resistivity in the 1010 γ-cm range. Low temperature photoluminescence study shows very good crystalline quality and a very low concentration of deep level recombinations. Single crystal samples were diced into 1 cm squares for evaluation as gamma ray detectors. The best detector results (4.5% resolution at 60 keV) were achieved for a 2 hour anneal at 850°C.
Pulse Filtering and Correction For CZT Detectors Using Simple Digital Algorithms Based on The Wavelet Transform
Authors: Pérez J. M. , García-Belmonte G. 
Published: April 2011

AbstractWe report an approach to double gaussian filtering used in classical works as dual parameter pulse processing. This technique has been implemented by creating a bank of gaussian-like digital filters based on wavelet transforms. A simple method to correct for the charge loss inherent to room temperature semiconductor gamma detectors has been developed. This method is based on multi-resolution signal analysis. Results are reported from tests of these algorithms on commercial CZT detectors and two trapped hole charge correction levels are compared. Finally, the advantages and limitations of this new approach to detector pulse processing are discussed.
HgI2 Two-Dimensional Arrays Based on Resistive Charge Division Readout
Authors: Alfieri S. , Cesare N. De , Grassi D. , Perillo E. , Spadaccini G; , Vigilante M. , Dusi W. , Amann M. , Koebel J. M. , Siffert P. 
Published: April 2011

AbstractNewly designed HgI2 two-dimensional arrays based on resistive charge division, obtained by depositing a Ge surface resistive layer between the readout Pd strips, have been fabricated. These detectors, coupled with very low noise preamplifiers, have shown a high detection efficiency over a large active area and an energy resolution of 15% for X-ray energy Ex =60 keV (241Am), becoming ≈ 9% at Ex = 122 keV (57Co). Further, a spatial sensitivity of ≈ 5 μm and a spatial resolution of ≈ 40 μim in both the directions parallel to the anode and to the cathode strips have been obtained at an energy equivalent to ≈ 40 keV, by making use, for a fine spatial characterization of the devices, of a laser beam spot with wavelength tuned to match the crystal bandgap (582 nm). These devices, with optimized cathode layer resistances, could be successfully employed in basic research (for example Bragg X-ray spectrometry) and for imaging in radiological and space applications, at least in the important energy range 40 <Ex <120 keV.
New Generations of Position Sensitive Silicon Detectors
Authors: Burger P. , Keters M. , Van Buul L. , Verplancke J. 
Published: April 2011

AbstractThe new generation of elementary particle and nuclear physics experiments demand instrumentation with a more precise spatial resolution and a better and faster energy response. Nuclear physics and space experiments need position sensitive pad detectors having very thin entrance windows while high energy physics and medical applications use fast microstrip or drift detectors. Silicon pixel detectors can be improved by implementing integrated electronics on it. They allow a better X-ray energy resolution and are also used in hybrid photocathode tubes for faster timing and larger dynamic range.
Radiation Damage Of InGaAs Photodiodes By High Energy Particles
Authors: Kudou T. , Ohyama H. , Simoen E. , Claeys C. , Takami Y. , Shigaki K. , Fujii A. , Sunaga H. 
Published: April 2011

AbstractResults are presented of a study on the performance degradation and the induced lattice defects of In0.53Ga0.47As p-i-n photodiodes, subjected to 220-MeV carbon particles. The effects on both the dark current and the photo-current are investigated as a function of the carbon fluence and correlated with DLTS results. The device degradation is compared with the one observed after exposure to 1-MeV electrons, 1-MeV fast neutrons and 20-MeV alpha rays, respectively. The differences in damage coefficients will be explained in view of the calculated number of knock-on atoms and the nonionizing energy loss (NIEL). The recovery behavior of the diode performance and of the induced deep levels by isochronal annealing is also reported.
Properties Of Zinc Selenide Grown By Chemical Vapor Transport And Its Application To Room-Temperature Radiation Detection
Authors: Brunett B. A. , Toney J. E. , Yoon H. , Rudolph P. , Schieber M. , Schlesinger T. E. , Goorsky M. S. , James R. B. 
Published: April 2011

AbstractWe have characterized ZnSe material grown by chemical vapor transport in iodine using triple-axis X-ray diffraction (TAD), photo-induced current transient spectroscopy (PICTS), photoluminescence (PL), current-voltage measurements and gamma-ray spectroscopy. The material was found to have inadequate carrier transport for nuclear spectrometer use, but there was a discernible difference in performance between crystals which could be correlated with crystallinity as determined by the TAD rocking curves.