bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hrem Study of Ultra Thin Titanium Films
Authors: Braisaz T. , Ruterana P. , Nouet G. , Komninou Ph. , Kehagias Th. , Karakostas Th. , Poulopoulos P. , Aggelakeris M. , Flevaris N. , Serra A. 
Published: April 2011

ABSTRACTHigh resolution electron microscopy has been used to characterize the structure of ultra thin films of titanium deposited on KBr substrate by Ultra High Vacuum (UHV) electron-gun evaporation. The size of the grains has an order of magnitude of 10 nm whatever the substrate temperature. The observations have been carried out along <1123> zone axis. Some of the grains contain planar defects which were identified as the twin {1011}. The atomic structure of this twin is characterized by a mirror plane similar to that observed in polycrystalline titanium. Additionaly, this structure can be modified by a b2/2 twinning dislocation.
Use of Malonic Acid in Chemical-Mechanical Polishing ( CMP ) of
Tungsten
Authors: Zhang L. , Raghavan S. 
Published: April 2011

ABSTRACTThe use of malonic acid as an additive in alumina slurries used for the
chemical mechanical polishing ( CMP ) of tungsten has been explored for the
reduction of particulate contamination. The principal objective of this work
was to delineate conditions under which alumina contamination on polished
surfaces could be reduced.The interaction between malonic acid and alumina particles has been
investigated through electrokinetic and adsorption measurements. At suitable
malonic acid concentrations and pH values, tungsten and alumina surfaces
develop a negative zeta potential resulting in conditions conducive to
reduced particulate contamination. Small scale polishing experiments have
been carried out to relate electrokinetic results to the level of
particulate contamination after polishing.
Post Metal Etch Treatment for Submicron
Applications
Authors: Gonzales Simon , Grivna Gordy , McAfee Anda 
Published: April 2011

ABSTRACTCorrosion control and passivation of post metal etch structures are critical
for submicron applications and overall yield performance. This study focused
on 0.6 micron metal line spaces and the development of a process utilizing
an integrated metal etch, photoresist strip and passivation tool. Data
collected to characterize the corrosion/passivation mechanism included: veil
and photoresist strip chemistries, passivation steps, time delays,
subsurface material versus veil formation and electrical and defectivity
yield. A post metal etch process was tested and integrated into a
manufacturing environment that has provided minimal line loss, complete
removal of etch veils, robust corrosion control and substantial reduction of
intermetal shorts.
Etching Characteristics During Cleaning of Silicon Surfaces by
NF3-added Hydrogen and Water-Vapor Plasma Downstream
Treatment
Authors: Suzuki Miki T. , Kikuchi Jun , Nagasaka Mitsuaki , Fujimura Shuzo 
Published: April 2011

ABSTRACTHydrogen and water vapor plasma downstream treatment with the downstream
injection of NF3 removes native oxide from silicon surfaces. In
contact hole cleaning, this dry processing is a promising alternative to HF
wet treatment, which has a problem of expansion of hole diameter. We
examined the etching characteristics of boron-phosphosilicate glass (B-PSG)
films, as a typical oxide material for the side-walls of the contact holes
and compared the etching depths of B-PSG and thermal oxide films. We found
that the etching depths of B-PSG films fell to one third of those of thermal
oxide films at lower treatment temperature. This result indicates that the
expansion of contact hole diameters can be minimized.
SI3N4 Particle Removal Efficiency
Study
Authors: Liu Jane Qian , Lee Carolyn , Rosamilia Joseph M. , Boone Tom , Czitrom Veronica , Higashi Gregg S. 
Published: April 2011

ABSTRACTControlling particle contamination in wafer cleaning is important to reduce
defect density and improve device performance and yield. In this study, a
screening experiment was employed to evaluate particle removal efficiency
among different cleanings, including FSI BCLN, bench rinse and dry only,
bench SC1/megasonic only, bench RCA cleaning, and bench RCA-based cleaning.
To optimize particle removal efficiency in RCA-based cleaning, a design of
experiment (DOE) has been done to investigate the impact of SC1/megasonic
cleaning on Si3N4 particle removal efficiency. Bath
temperature, megasonic power, and solution chemistry of SCI bath were
evaluated. The removal efficiency in relations to particle sizes was also
investigated
Comparison of High-Purity-Ozone Oxidation on Si(111) and
Si(100)
Authors: Kurokawa A. , Ichimura S. , Moon D. W. 
Published: April 2011

ABSTRACTThe oxidation of Si(111) and Si(100) surfaces with the high-purity
ozone(more than 98 mole %) was investigated with X-ray photoelectron
spectroscopy (XPS). Thin oxide less than 3nm thickens was formed in an
experimental chamber and the results showed that ozone oxidizes the (111)
surface faster than (100) surface. Ozone does not show the temperature
dependence on oxidation within the temperature range of 250–500 degree C for
both (111) and (100) surfaces. Ozone proceeds the oxide formation at 700
degree C where oxygen does not proceed oxide formation rapidly.
State-of-the-Art Evaluation of Ultra-Clean Ulsi
Processes
Authors: Fischer-Colbrie A. , Laderman S. S. , Brennan S. , Ghosh S. , Takaura N. , Pianetta P. , Shimazaki A. , Waldhauer A. , Wherry D. , Barkan S. 
Published: April 2011

ABSTRACTThis work describes recent progress in implementation and applications of
synchrotron radiation total reflection x-ray fluorescence (SR-TXRF) to
measure trace metals on wafer surfaces. To date, we have achieved
state-of-the-art transition metal sensitivity of 3×108
atoms/cm2 (˜3fg) for 1000 sec. counting time for impurities
which have an monolayer-like distribution on the surface and <1fg for
droplet-like impurities. Recent instrumentation breakthroughs include
reduction of detector parasitic backgrounds (particularly Cu) to below our
present detection limit, 150 and 200mm whole-wafer handling, wafer-mapping
capability and a cleanroom mini-environment. With these upgrades,
measurements were made of wafers from various steps in the integrated
circuit fabrication process. These results demonstrate that synchtron
radiation brings TXRF into a new and useful regime. Further developments are
underway to increase throughput and access for broader application.
Pulsed Laser Assisted Particulate Cleaning of Solid
Surfaces
Authors: Kumar D. , Ivory S. , Mahajan U. , Singh Rajiv K. 
Published: April 2011

ABSTRACTIn the this paper, we have examined the particulate removal efficiency of
laser from solid surfaces. The silicon wafers were contaminated with alumina
particles with sizes ranging from 0.05 μm to 0.5 μm. The silicon wafers with
uniform surface-distribution of alumina particles were subjected to pulsed
laser beams at varying conditions. The results obtained have shown that line
beam lasers can remove submicron particles more efficiently from solid
surfaces. The mechanism responsible for higher particulate
removal-efficiency of line beam laser has also been discussed.
Cleaning Technologies using Electrolytic Ionized Water and
Analysis Technology of Fine Structures for Next Generation Device
Manufacturing
Authors: Aoki Hidemitsu , Yamasaki Shinya , Nakamori Masaharu , Aoto Nahomi , Yamanaka Koji , Imaoka Takashi , Futatsuki Takashi 
Published: April 2011

ABSTRACTTo reduce the consumption of chemicals and ultra pure water (UPW) in
cleaning processes used in device manufacturing, we have developed wet
processes that use electrolytic ionized water (EIW), which is generated by
the electrolysis of a diluted electrolyte solution or UPW. EIW can be
controlled for wide ranges of pH and oxidation-reduction potential. Anode
EIW with diluted electrolyte, which has high oxidation potential, can remove
metallic contamination such as Cu and Fe on Si surfaces. EIW contains less
than 1/100 of the amount of chemicals contained in conventional cleaning
solutions, thus drastically reduces chemical consumption in wet processes.
Moreover, electrolyzed UPW can be used as a substitute for conventional UPW
to achieve better rinsing characteristics. Electrolyzed UPW reduces the
level of residual SO42− ions after SPM cleaning more efficiently than conventional
UPW. Thus the amount of rinse water needed is reduce to 1/6 that of the
conventional UPW rinse.We also developed a method for analyzing remaining metallic contamination
and residual ions in deep-submicron-diameter holes with high aspect ratios.
The method is based on conventional atomic absorption spectrometry (AAS),
and uses device patterns with high density contact holes. With this method,
metallic (Fe) contamination on the order of 1010
atoms/cm2 can be easily analyzed inside 0.1 μm-diameter holes
with an aspect ratio of 10. The residual ions in the fine holes can also be
detected by thermal desorption spectroscopy (TDS).
Low Thermal Conductivity Skutterudites
Authors: Fleurial J.-P. , Caillat T. , Borshchevsky A. 
Published: April 2011

AbstractRecent experimental results on semiconductors with the skutterudite crystal structure show that these materials possess attractive transport properties and have a good potential for achieving ZT values substantially larger than for state-of-the-art thermoelectric materials. Both n-type and p-type conductivity samples have been obtained, using several preparation techniques. Associated with a low hole effective mass, very high carrier mobilities, low electrical resistivities and moderate Seebeck coefficients are obtained in p-type skutterudites. For a comparable doping level, the carrier mobilities of n-type samples are about an order of magnitude lower than the values achieved on p-type samples. However, the much larger electron effective masses and Seebeck coefficients make n-type skutterudites promising candidates as well. Unfortunately, the thermal conductivities of the binary skutterudite compounds are too large, particularly at low temperatures, to be useful for thermoelectric applications.Several approaches to the reduction of the lattice thermal conductivity in skutterudites are being pursued: heavy doping, formation of solid solutions and alloys, study of novel ternary and filled skutterudite compounds. All those approaches have already resulted in skutterudite compositions with substantially lower thermal conductivity values in these materials. Recently, superior thermoelectric properties in the moderate to high temperature range were achieved for compositions combining alloying and “filling” of the skutterudite structure. Experimental results and mechanisms responsible for low thermal conductivity in skutterudites are discussed.
Materials for Mid-Infrared Semiconductor Lasers
Authors: Kost A. R. 
Published: April 2011

AbstractA variety of semiconductor materials have been used to fabricate diode lasers for the midinfrared. Lasers using the lead salts (e.g. PbSnTe) have been commercially available for some time. Mid-infrared emitting III-V semiconductors (e.g. InGaAsSb) have superior thermal conductivity, and diode lasers fabricated from these materials offer higher powers. Of particular interest are the III-V semiconductor lasers based on type-II superlattices (e.g. InAs/GaInSb). Among the many unique properties attributed to type-Il superlattices are small hole mass, reduced Auger recombination, and less inter-valence band absorption - all important for better lasers. Recent results with Quantum Cascade-type lasers are also very encouraging. This paper summarizes the important semiconductor materials for mid-infrared lasers with emphasis on the type-II superlattices.
Raman and Photo-Luminescence Studies on Intrinsic and Cr-Doped Znse Single Crystals
Authors: Rai Brajesh K. , Bhaskar S. , Bist H. D. , Katiyar R. S. , Chen K.-T. , Burger A. 
Published: April 2011

AbstractSingle crystals of ZnSe, with varying amounts of Cr doping have been studied using Raman and photoluminescence(PL) spectroscopy. The Cr-doped samples show the existence of a coupling mechanism of longitudinal optical(LO) phonons of ZnSe with hole-plasmons. The dependence of intensity ratio of LO and transverse optical(TO) mode on temperature and excitation wavelength, has been attributed to the interaction of the field of LO phonons with the surface electric field in the depletion layer. The interaction of discreet phonons with the electronic continuum of conduction band in ZnSe is responsible for the shift of Raman peaks. The large electron capture cross-section of deep-level Cr2+ and Cr1+ impurities is inhibitive for the observation of band-to-band PL transition at ∼2.7eV in ZnSe:Cr.
Extracting Trap Parameters From Picts Spectra In Cadmium Zinc Telluride Radiation Detector Material
Authors: Toney J. E. , Brunett B. A. , Schlesinger T. E. , James R. B. 
Published: April 2011

AbstractWe demonstrate that the regularization method due to Weese can resolve closely-spaced peaks in PICTS spectra for cadmium zinc telluride. We also show that electron and hole traps can be distinguished from each other by the bias dependence of the spectrum when using an excitation source that is primarily infrared but which contains a small component of visible light. Lastly we show that there are qualitative differences between PICTS spectra taken with infrared excitation and those taken with visible excitation. We attribute the surface-related levels to diffusion into the detector material of gold from electroless deposition of contacts.
Simulated and Associated Experimental Results of CdZnTe Radiation Detector Response for Gamma-Ray Imaging Applications
Authors: Verger L. , Bonnefoy J. P. , Gliere A. , Ouvrier-Buffet P. , Rosaz M. 
Published: April 2011

AbstractSimulated and associated experimental results of a high efficiency CdZnTe (CZT) radiation detector response for gamma-ray imaging applications are presented. The model of a high efficiency semiconductor gamma ray detector takes into account several different physical phenomena involved in the detection and correction processes, namely the geometry of the irradiation, the gamma-ray's interaction with the crystal, the physics of the semiconductor's charge collection, the electric field distribution and the pulse height correction method. A few important decoupling assumptions allow us to use a one dimensional charge collection simulation with a two-dimensional field model and a full three dimensional Monte-Carlo calculation of the gamma ray interactions. The model allows calculation of charge collection and gamma ray spectra for non uniform electric field distribution in either planar, striped or pixellated detector.The model takes also into account the new CZT fast pulse correction method and its associated noise by considering the pulse height and the rise time of electron signals (Bi-Parametric spectrum) for all gamma ray interactions. Specific simulated and experimental spectra at 122 keV are presented for CZT. First, basic spectral changes are calculated for variations in crystal and detector properties like mobility, trapping lifetime and electric field profilesSecond, new experimental results of the fast pulse correction method applied to different CZT detector grades are presented. This method allows to achieve a high detection efficiency (> 80 %) with a good energy resolution (< 6 % FWHM) at 122 keV for a 4×4×6 mm3 CZT detector. No specific contact geometry is needed and the unusual low applied bias voltage allows to limit the ageing and break voltage effects and also the dark current and its associated noise. This fast correction method is expected to be useful for medical imaging and other applications.Finally, simulated Bi-Parametric (BP) spectra expected with the fast pulse correction method according to the detector properties (electric field profiles, electron lifetime) are simulated and a qualitative comparison is provided.
High Energy Flux Detector Using CdTe P-I-N Layers
Authors: Niraula Madan , Arakawa Tomonori , Aoki Toru , Nakanishi Yoichiro , Hatanaka Yoshinori , Kan Hirofumi 
Published: April 2011

Abstractn-and p-type doping of CdTe grown heteroepitaxially on GaAs substrate by radical assisted metal organic chemical vapor deposition technique were studied. n-type doping was studied by the gas phase n-butyliodine doping during the film growth, whereas p-type doping was carried by treating the undoped layers with alkaline metal compound (Na2Te) and excimer laser radiation. Highly conductive n-and p-layers were thus obtained which formed good ohmic contact with aluminum and gold electrodes, respectively. Using this technique, n-and p- layers were formed on intrinsic CdTe substrate to form p-i-n diode. This p-i-n structure showed a good diode characteristics and good sensitivity to X-ray radiation with dark current in the order of nA/mm 2 at room temperature.
Characterization of X-Ray Imaging Properties of PbI2 Films
Authors: Shah K. S. , Bennett P. , Cirignano L. , Dmitriyev Y. , Klugerman M. , Mandal K. , Moy L. P. , Street R. A. 
Published: April 2011

AbstractThis paper describes our recent research in developing vacuum sublimed lead iodide films for X-ray imaging. Lead iodide films are promising for this application due to their low dark current, high stopping efficiency, reasonably good charge transport, low cost, and relatively easy scale-up. Lead iodide films (up to 5 × 5 cm2 area) have been grown and characterized by measuring their X-ray imaging properties such as spatial resolution, and contrast transfer function. Excellent spatial resolution (> 10 lp/mm with high CTF ≈50%) has been recorded with PbI2 films. Relevant detection properties such as signal amplitude for given X-ray energy has also been measured and was found to be about 10 times larger as compared to standard phosphor screens used for X-ray imaging. Charge transport and timing characteristics of these films have been measured and the results indicate that these films should be capable of real-time operation. Application of these films for X-ray imaging such as mammography, fluoroscopy, and X-ray diffraction is addressed.
Calorimetric and Spectroscopic Characterization of Zone Refined and Regrown Lead Lodide
Authors: Chen K.-T. , Burger A. , Chen H. , Chen Y.-F. , Hansen K. , Suber L. , Wilson S. , Henderson J. , Wright G. W. , Cole M. L. 
Published: April 2011

AbstractLead iodide starting materials have been purified by vertical zone refining process. The purest materials of the zone-refined ingot, middle zone, were used for single crystal growth by Bridgman method. Differential scanning calorimetry, current-voltage and low temperature photoluminescence measurements were employed to investigate the effectness of zone refining process and as-grown crystal. The results showed that the materials from the middle section of zone-refined ingot is the purest, followed by first-to-freeze and last-to-freeze materials. No second phase and deviation from stoichiometry have been observed after zone refining process and Bridgman crystal growth method. The resistivities increase as the purity and crystallinity of materials increases. Cleavage of as-grown crystal did damage the surface and caused additional emission at 2.0 eV. This emission band was not observed after a 10% NaI solution etching.
Compound Semiconductor Detectors for X-Ray Astronomy: Spectroscopic Measurements and Material Characteristics
Authors: Bavdaz M. , Kraft S. , Peacock A. , Scholze F. , Wedowski M. , Ulm G. , Nenonen S. , Gagliardi M. A. , Gagliardi T. , Tuomi T. , Hjelt K. T. , Juvonen M. 
Published: April 2011

AbstractThe use of some specific compound semiconductors in the fabrication of high energy X-ray detectors shows significant potential for X-ray astrophysics space missions. We are currently investigating three high purity crystals - CdZnTe, GaAs and TlBr - as the basis for future hard X-ray detectors (above 10 keV). In this paper we present the first results on CdZnTe and GaAs based detectors and evaluate the factors currently still constraining the performance.Energy resolutions (FWHM) of 0.9 keV and 1.1 keV at 14 keV and 60 keV, respectively, have been obtained with an epitaxial GaAs detector, while 0.7 keV and 1.5 keV FWHM were measured at the same energies with a CdZnTe detector. Based on these results it is clear, that the next generation of X-ray astrophysics missions now in the planning phase may well consider extending the photon energy range up to ∼100 keV by use of efficient detectors with reasonable spectroscopic capabilities.
Pbte(Ga) - New Multispectral Infrared Photodetector
Authors: Belogorokhov A. I. , Ivanchik I. I. , Khokhlov D. R. 
Published: April 2011

AbstractDoping of the lead telluride - narrow-gap semiconductor - with gallium results under certain conditions in the Fermi level pinning in the gap thus providing the semiinsulating state of material. Besides that, the persistent photoconductivity effect is observed at a temperatures T < Tc = 80 K. The photoresponse kinetics consists of two parts: the slow one with the characteristic time tchar going up to 104 s at T = 4.2 K, and the fast part with tchar, of the order of 10 ms. We have measured the spectra of a fast part of the photoresponse using the Fouriertransform spectrometer “Bruker” IFS- 113v. The photoconductivity is observed in two spectral regions: in the middle- and far - infrared. Response in the middle-infrared consists of the ordinary fundamental band and a strong superimposed resonance-like structure just at the bandgap energy. The position of this spectral line may be tuned in a wide range (3.5–5.5) μm by variation of temperature and/or composition of a lead telluride-based alloy. This middle-infrared photoresponse becomes considerable already at T = 160 K. The photoresponse in the far-infrared may be depending on the excitation conditions an analogous resonance-like structure at a wavelength 70 μm, or a broad band with the cutoff wavelength at least higher than 500 μm, which is the highest cutoff wavelength for the photon detectors observed up to date.
Photoluminescence Investigation of Surface Oxidation of C0.9Zn0.1 Te Detectors
Authors: Chen H. , Hayes M. , Chattopadhyay K. , Chen K. T. , Burger A. , Heffelfinger J. , James R. B. 
Published: April 2011

AbstractThe effect of surface oxidation of Cd1−xZnxTe (x = 0.1) detectors by chemical etching in hydrogen peroxide aqueous solution (H2O2) at different concentrations and etching times was investigated by low temperature photoluminescence (PL). The treatment resulted in better surface condition evidenced by the larger I(D0, X)/Idef intensity ratio and the narrower full width at half maximum of the main peak (D0, X). Peak shifts in the PL spectra associated with bound exciton lines and free to bound transition were also observed and attributed to the oxide layer. These surface effects were found to be dependent on H2O2 concentration and etching time. The significance of this surface oxidation on device passivation and the subsequent improvements in the detector performance are also discussed.
Ac Susceptibility Studies of New and Familiar Magnetic Molecular Solids
Authors: Sommer Roger D. , Korte Brenda J. , Sellers Scott P. , Yee Gordon T. 
Published: April 2011

Abstractac Susceptometry has been used to study a number of magnetic molecular solids including a new compound, Mn(II) octaethyltetraazaporphyrin, α-MnOETAP, and decamethylmanganocenium tetracyanoethenide, Mn(Cp*)2•TCNE, a previously reported molecule-based ferromagnet. Both of these compounds exhibit signatures of ferromagnetism including significant hysteresis below 2 K and rapidly increasing χT (where χ is the molar susceptibility) with decreasing temperature. However, their ac susceptibility data show relatively strong dependence of χ′ and χ″ on the frequency of the applied field, indicating a spinglass state. Other molecular ferromagnetic solids examined show much less sensitivity. These studies indicate that the standard practice of characterization by dc and ac susceptometry at a single frequency are clearly insufficient for identifying the magnetic state of a molecular solid.