bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Electrical Properties of In-situ Doped Polycrystalline Silicon Thin Films Grown by Electron Cyclotron Resonance Chemical Vapor Deposition at 250°C
Authors: Jiang Yeu-Long , Wang Ruo-Yu , Hwang Huey-Liang , Yew Tri-Rung 
Published: April 2011

AbstractThe phosphorus doped polycrystalline silicon thin films were grown by Electron Cyclotron Resonance Chemical Vapor Deposition (ECR-CVD) at 250°C. The doping gas PH3 was in-situ added with SiH4 gas during the films deposition. All films were deposited with 90% hydrogen dilution ratio. The resistivity of the films is varied from 0.2 to 7Ω-cm and decrease as the PH3/SiH4 gas ratio increase from (3/100 to 7/100). From the SIMS data, the doping concentration is all about 1020cm-3. The activation energy is decreased from 0.35 eV to 0.12 eV as the dopant concentration increased from 0.8×10 20cm-3 to 4.7×10 20cm-3. From the Hall measurements, the carrier mobility is about 2∼4 cm2/V. sec, and the carrier concentration is the 0.5∼1% of the dopant concentration. The gain boundary trap density predicted by the trapping model is about 4×l013cm” 2-2
Analyses of the Grain Boundary Misorientation and Oxygen Content of Bulk Processed YBa2Cu3O7-δ
Authors: Wang Jenn-Yue , King Alexander H. , Zhu Yimei , Wang Yuan-Liang , Suenaga Mas Aki 
Published: April 2011

ABSTRACTThe grain boundary misorientation distribution of 203 grain boundaries in bulk processed high Tc superconductor YBa2Cu3O7-δ with five processing conditions, was studied. Two complementary analytical approaches, Grain Boundary Misorientation Distribution (GBMD) from the random description, using a hypothesis test and X2 analysis, and Grain Boundary Character Distribution (GBCD), using the Coincidence Site Lattice (CSL) model, were applied. The GBMD and GBCD both showed grain boundary evolution departing from a random distribution above 935°C processing temperature. The GBCD analyses indicated an approximately linear increase in the population of CSL-related boundaries, among which the tetragonal CSL (c/a ≠ 3) boundaries grew in the same trend while orthorombic boundaries (c/a = 3) became stagnated. The results from comparing the corresponding GBCD and volume averaged Jc for each batch indicated that the tetragonal CSL boundaries were oxygen deficient and accounted for, among other current limiting factors, lower current carrying ability.
SPFM Pre-Cleaning for formation of Silicon Interfaces by Wafer
Bonding
Authors: Bengtsson Stefan , Ljungberg Karin 
Published: April 2011

ABSTRACTThe use of H2SO4:H2O2:HF (SPFM)
at low HF concentrations (10 to 1000 ppm) has been investigated as the
preparation procedure prior to formation of Si/Si interfaces by wafer
bonding. The SPFM cleaning process makes it possible to form a hydrophilic
(OH terminated) silicon surface, thereby achieving a spontaneous and strong
room temperature bond. Electrical characterization using current vs voltage
and spreading resistance measurements shows that this cleaning procedure can
be used to form Si/Si junctions with excellent electrical properties. Some
of the problems related to hydrophobic wafer bonding can thus be
circumvented by the proposed technique.
Oxidation Resistance of Ultrathin Silicon Nitride Passivation
Layers on Si(100)
Authors: Kamath A. , Kim B. Y. , Blass P. M. , Sun Y. M. , White J. M. , Kwong D. L. 
Published: April 2011

ABSTRACTThe oxidation resistance of ultrathin (5–15Å) thermally grown silicon
nitride (Si3N4), in conditions relevant to the
deposition/annealing of Tantalum Pentoxide (Ta2O5) in
a Rapid Thermal Processing (RTP) environment, has been non destructively
examined using X-Ray Photoelectron Spectroscopy (XPS). This has been carried
out with a view to establishing a process window for the deposition of
Ta2O5 on a Rapid Thermally Nitrided (RTN) Si(100)
surface, with negligible oxidation of the Si(100) substrate. A physical
model of the oxidation process of these films is also proposed.
An Analysis of Infrared Spectroscopic Geometries
Authors: Merklin Gregory T. , Luo Huihong , Chidsey Christopher E. D. 
Published: April 2011

ABSTRACTThe influence of experimental geometry on the signal strength and
signal-to-noise ratio of infrared spectrometry has been investigated. In
general, it was found that the choice of optimum experimental geometry
depended on the orientation of the vibrational mode being investigated. In
particular, it has been calculated that internal reflection spectrometry is
relatively insensitive to vibrational modes perpendicular to the surface
relative to transmission spectroscopy at Brewster's angle, and this has been
confirmed by experiment.
Ni Removal from Si Wafers by Low-Pressure UV-Chlorine
Cleaning
Authors: Courtney C. H. , Lamb H. H. 
Published: April 2011

ABSTRACTNi removal from Si wafers by low-pressure UV/Cl2 chemical vapor
cleaning (CVC) was investigated at substrate temperatures of 150–200°C.
Sub-monolayer Ni coverages were applied to Si(100) by ultrahigh-vacuum
physical vapor deposition (UHV-PVD). The Ni surface concentration was
reduced to the Auger electron spectroscopy (AES) detection limit by a 2-min
UV/Cl2 exposure at 300 mTorr and 200°C. AES depth profiling
revealed that Ni was not contained within nor buried beneath the chlorosilyl
layer formed by UV/Cl2 CVC. In contrast, Ni was not removed under
similar conditions from Si surfaces covered by a thin UV/air oxide layer.
These results indicate that Ni removal from Si occurs by a photochemical
etching mechanism and not by direct volatilization of NiCl2.
Atomic force microscopy (AFM) of Si surfaces after UV/Cl2 CVC
indicated that Si etching was limited ˜20 å and that the surface was smooth
(RMS roughness = 1.6 å).
Water use Efficiency in Immersion Wafer Rinsing
Authors: Roche Thomas S. , Peterson Thomas W. , Hansen Eric 
Published: April 2011

ABSTRACTThis work is an effort to determine if we can use less water effectively in
rinse processes. We have run experiments to examine our current usage and to
determine if we can use water more effectively.This work will describe the experiments which have been done relating the
amount of chemical remaining on the wafers to variables of the: rinse such
as flow rate, wafer spacing and the cycling of the rinse valves. We will
discuss the conclusions we have reached based on those experiments and the
directions we will be taking to improve rinsing efficiency.
Advanced Thermoelectric Materials and Systems for Automotive Applications in the Next Millennium
Authors: Morelli Donald T. 
Published: April 2011

AbstractA combination of environmental, economic, and technological drivers has led to a reassessment of the potential for using thermoelectric devices in several automotive applications. In order for this technology to achieve its ultimate potential, new materials with enhanced thermoelectric properties are required. Experimental results on the fundamental physical properties of some new thermoelectric materials, including filled skutterudites and 1–1–1 intermetallic semiconductors, are presented.
Positive and Negative Luminescent Infrared Sources and Their Applications
Authors: Ashley T. 
Published: April 2011

AbstractWe describe uncooled mid-infrared light emitting and negative luminescent diodes made from indium antimonide based IlI-V compounds, and long wavelength devices made from mercury cadmium telluride. The techniques to produce large area positive and negative luminescent sources, and the application of these devices to gas sensing, improved thermal imagers and imager testing is discussed.
Recent Progress in the Growth of Mid-ir Emitters by Metalorganic Chemical Vapor Deposition
Authors: Biefeld R. M. , Allerman A. A. , Kurtz S. R. , Baucom K. C. 
Published: April 2011

AbstractWe report on recent progress and improvements in the metal-organic chemical vapor deposition (MOCVD) growth of mid-infrared lasers and using a high speed rotating disk reactor (RDR). The devices contain AlAsSb claddings and strained InAsSb active regions. These lasers have multi-stage, type I InAsSb/InAsP quantum well active regions. A semi-metal GaAsSb/InAs layer acts as an internal electron source for the multi-stage injection lasers and AlAsSb is an electron confinement layer. These structures are the first MOCVD multi-stage devices. Growth in an RDR was necessary to avoid the previously observed Al memory effects found in conventional horizontal reactors. A single stage, optically pumped laser yielded improved power (> 650 mW/facet) at 80 K and 3.8 μm. A multi-stage 3.8–3.9 μm laser structure operated up to T=170 K. At 80 K, peak power > 100 mW and a high slope-efficiency were observed in gain guided lasers.
Theory of Critical Layer Thickness of Nonconstant Quantum-Well Width Produced by Interdiffusion and its Optoelectronics Consequence
Authors: Chan Michael C. Y. , Li E. Herbert 
Published: April 2011

AbstractIn this paper, the concept of critical layer thickness is applied to the interdiffused quantum well (DFQW) structure. For the as-grown InGaAs/LnP lattice matched quantum well, the interdiffusion process will induce in-plane strain into the DFQW forming a lattice mismatched system. The relation between the as-grown well width (Lz) and the diffusion length (Ld) for formation of dislocation is presented.
Analysis of AlGaAs/GaAs Multiple Quantum Well Dual Waveguides Defined by Ion Implantation Induced Intermixing
Authors: Lo Kai-Ming 
Published: April 2011

AbstractA simple and accurate model is presented for the study of ion-implanted AlGaAs/GaAs multi-quantum well dual waveguides. The impurity induced disordering defined multiquantum well dual waveguides are shown to have similar optical properties as conventional dielectric rib waveguides. They also provide a more flexible control over the waveguiding and coupling characteristics by changing parameters such as diffusion time, ion implant energy, mask width, and waveguide separation.
Atomistic Calculations of Dopant Binding Energies in ZnGeP2
Authors: Pandey Ravindra , Ohmer Melvin C. , Costales A. , Recio J. M. 
Published: April 2011

AbstractAtomistic model has been applied to study various cation dopants, namely Cu, Ag, B, Al, Ga and In in ZnGeP2. The pairwise interatomic potential terms representing the interaction of dopants with the host lattice ions are derived using first principle methods. Defect calculations based on Mott-Littleton methodology predict small binding energies for Cu and Ag substituting Zn in the lattice which are in agreement with the available experimental data. The group III dopants (i.e. B, Al, Ga and In) at the Ge site are predicted to have large binding energies for a hole except B which shows a distinct behavior. This may be due to large mismatch in atomic sizes of B and Ge. At the Zn site, the calculated binding energies of the group III dopants place donor levels in the middle of the band gap.
Operational Characteristics of GaSe Crystals for Mid-IR and Far-IR Applications
Authors: Fernelius N. C. , Hopkins F. K. , Singh N. B. , Suhre D. , Marable M. , Hopkins R. H. , Meyer R. , Mui P. 
Published: April 2011

AbstractGaSe has a number of attractive properties for nonlinear optical applications including large birefringence for ease in phase matching. Its biggest drawback is its mechanical properties. GaSe has a strong tendency to cleave along the <100> plane which has made it difficult to grow and fabricate. We have developed a method to modify GaSe by structurally strengthening the material by doping. We have synthesized large boules of GaSe reacted mixtures and grown centimeter size single crystals by the Bridgman technique. Depending on the dopant and crystal quality, SHG measurements indicate a deff, of 51 to 76 pm/V. SHG power levels were theoretically calculated and appear to be in good agreement with the experimental data. The measured performance of crystals for the fourth harmonic generation and laser damage threshold are also reported in this paper. The damage threshold was greater than 2.8 J/cm2 and 85 KW/cm2 at the surface of the crystal.
High Efficiency, Spectroscopic CZT Array
Authors: Cirignano L. , Klugerman M. , Dmitriyev Y. , Bennett P. , Shah K. S. , Bloser P. , Narita T. , Grindlay J. 
Published: April 2011

AbstractCompact, efficient, spectroscopic detector arrays which preferably operate without cooling have applications in the fields of x-ray astronomy, nuclear medicine and radioactive materials management. We have fabricated a 16 element CdZnTe detector array that provides a stopping efficiency of greater than 80%, a photopeak fraction of 44% and an energy resolution of 3.2 keV FWHM at 122 keV. The 4 × 4 array uses a pixel size of(1.5 mm)2 with 0.2 mm spacing on a 5 mm thick substrate. The variation in spectroscopic properties amongst pixels has been characterized in terms of energy resolution and detection efficiency. Operation in current (or flux) mode for transmission imaging has also been investigated.
Study of the Radiation Damage Induced by High Energy Gamma-Ray in CdTe Detectors
Authors: Chirco P. , Zanarini M. , Querzola E. , Zambelli G. , Dusi W. , Caroli E. , Cavallini A. , Fraboni B. , Siffert P. , Hage-Ali' M. 
Published: April 2011

AbstractIn recent years the performance of room-temperature semiconductor detectors such as CdTe are improved and they are now suitable candidates for several applications. However, some key parameters that can severely affect such perfomances have not been measured yet. Thus we have studied the damaging of a set of CdTe detectors irradiated in a 60Co gamma-cell in a wide range of doses and dose-rates. A full characterization of the performance of irradiated detectors has been obtained by means of spectroscopic, electrostatic, photo-induced current transient spectroscopy and photo-deep level transient spectroscopy measurements to quote the energy resolution, the leakage current, the activation energy and capture cross-section of deep level defects, respectively.
Converting Films for X-Ray Detectors, Applied to Amorphous Silicon Arrays.
Authors: Ross S. , Zentai G. 
Published: April 2011

AbstractThis paper presents results from our on-going efforts to characterize semiconductor thin films for direct x-ray conversion. We deposit these thin films onto an amorphous silicon (a-Si:H) readout array with the overall goal of developing a large area x-ray detector for protein crystallography, and for other x-ray imaging fields.
Degradation and Recovery of Si Diodes by 20-Mev Protons And 220-Mev Carbon Particles
Authors: Hakata T. , Ohyama H. , Simoen E. , Claeys C. , Sunaga H. , Kobayashi K. , Hososhima M. 
Published: April 2011

AbstractResults are presented of a study on the degradation of the electrical performance of Fe contaminated n+p Si diodes, subjected to a 220-MeV carbon irradiation. The reverse current of the diodes increases after irradiation, while the capacitance and hence the doping concentration decreases. The areal and peripheral components of the leakage current are extracted from diodes with different area to perimeter ratios. Both the generation and the recombination lifetime calculated from I/V and C/V characteristics also decrease. The deep levels in the Si substrate induced by the irradiation are mainly responsible for the degradation of the diode performance. The radiation damage is also studied for 1 -MeV electrons and 1 -MeV fast neutrons. The performance degradation for carbon irradiation is three orders of magnitude larger than that for electron irradiation. The differences in the radiation damage are explained by the differences in the number of knock-on atoms and the nonionizing energy loss (NIEL), which is attributed to the difference of mass and the possibility of nuclear collision with target Si atoms
Influence Of Ti Related Centers On ZnSe Radiation Spectra
Authors: Bruk L.I. , Korotkov V. A. , Ketrush P. I. , Simashkevich A. V. , Sushkevich K. D. , Kulyuk L. L. , Popov S. M. , Malikova L. V. 
Published: April 2011

AbstractZnSe annealed in (Zn + 46 wt.% TI) vapors and in Zn melt with 5 wt.% TI addition was investigated. The radiation spectra in the regimes of stationary and pulsed photoluminescence (PL) with the time delaying at 77K were studied. By using coloured cathodoluminescence (CCL) combined with the crystal cleavage image in the secondary electrons reflection the impurities and defects volume distribution was evaluated. It was revealed that at the annealing of ZnSe crystals in TI vapors, the cleavage surface has light blue radiation on the red background with an homogeneous field distribution with the dimensions ˜ 1..10μm. On the edge of the cleavage on the depth of 10μm the region of yellow radiation is observed. At the annealing in the melt the irradiation became blue on a weak red background, the homogeneity enhances. At the room temperature PL spectra correspond with images of cleavage in CCL. In the PL (at 77K) spectra in the exciton region there were observed: bands at 445nm (blue radiation); edge radiation at 460nm, 485nm with the LO phonons replica (blue region) and in the impurity region: bands 500...570nm (yellow-green radiation); 600...700nm and 720...800nm (red radiation). The investigation of PL of the annealed samples surface allowed the suppose, that the bands at 2,76eV (450nm), are stipulated by the free-bound transition on the acceptor center (E + 40meV), including TI.The comparison of ion and tetrahedronical covalent radiuses of Zn, Se and TI, electronegativity, probability of Zni and Vse. formation at the annealing allowed to suppose that, TI fills Vse. and forms (Zni Tls) and (Vse. Tlse) complexes. The carried out theoretical calculations according to the model of two-atom molecule gives the energy of complexes occurrence (Ev + 0,04) eV and (Ev + 0,8) eV. The first value accordingly is in good agreement with the experimental data.
Low Temperature Processed Metal-Semiconductor-Metal Phtodetectors on ZnSe/SI-GaAs (100)
Authors: Hong Hyesook , Anderson Wayne A. , Lee Eunwha , Chang Huicheng , Na Myunghee , Luo Hong 
Published: April 2011

AbstractLow temperature (LT) processed ZnSe MSM photodetectors can be used for detecting Gamma rays or X-rays using scintillation crystals in many space and medical applications. Metalsemiconductor-metal (MSM) photodetectors were fabricated on undoped ZnSe grown by molecular beam epitaxy (MBE) on semi-insulating (100) GaAs substrates. The MSM photodetectors consist of interdigitated metal fingers with 2 μm, 3 μm, and 4 μm spacing on one chip. Probimide and SiO2 thin films were deposited to aid the LT lift-off process before the pattern generation. An interdigitated structure was achieved by photolithography and reactive ion etching. Pd Schottky metal was deposited at a substrate temperature near 77 K using a lift-off technique. The LT metallization provides an improved interface between metal and semiconductor interface. Continuous wave signal to noise ratio (SNR) of 1.57×104 was obtained for 2 μm interdigitated photodetectors, operated under 180 nW optical power at a wavelength of 400 nm. The detectors showed good DC saturation characteristics indicating a low surface recombination. Saturation current without illumination remained at around less than 1 pA for a ± 10 V biasing. Detectors exhibited linearity with light intensity and DC bias voltage suggesting no gain mechanism involved, and showed a high spectral responsivity (0.6 (A/W)) at a wavelength of 450 nm at 5V applied bias.
Device Simulation of a Unipolar Gamma-Ray Detector
Authors: Lee E. Y. , Lund J. C. , Hilton N. R. , Brunett B. A. , James R. B. 
Published: April 2011

AbstractThe pulse height spectra from a new kind of unipolar gamma-ray detectors were predicted using a new three-dimensional simulation program developed at Sandia National Laboratories. The detectors were fabricated at Sandia and RMD Inc., and tested at Sandia. They were fabricated from Cd1-x.ZnxTe crystals and they were electron-transport-only devices. For the simulation, a successive overrelaxation method was used to determine the three-dimensional internal electric field within a detector, and to find the weighting potentials for the anode and the cathode. Uniform irradiation and ionization from a 137Cs source was assumed, and the charge transport and the signal induction within the detector were numerically computed using the appropriate materials and design parameters. The simulation gave excellent agreement with experimental pulse height spectra, and it demonstrated the power of such a simulation to correlate the materials parameters and the device design to the actual detector performance.
Growth and Characterization of Pbse and Pbl-Sn1 Se 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 experiments showed 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.
Photoexcitations of Oligothiophenes with Reduced Conformational Mobility
Authors: Rossi L. , Bongiovanni G. , Botta C. , Cerullo G. , Lanzani G. , Mura A. , Sannicolo F. , Benincori T. , Tubino R. 
Published: April 2011

AbstractWe present a comprehensive study of the optical and electronic properties of a series of oligothiophenes in which one or two inter-ring torsional angles have been blocked by chemical bridging. These give us the possibility to investigate the role of the conformational mobility and of the coupling with the inter-ring torsion on the deactivation process of the singlet excited states. We find that both the radiative and the non-radiative deactivation channels are affected by the inter-ring bridging.
Advantages of Modal Dispersion Phase-Matching and Materials Requirements for Polymeric Devices Using Efficient Second Harmonic Generation at Telecommunication Wavelength
Authors: Jäger Matthias L. , Ricci Vincent , Cho Wook-Rae , Canva Michael T. G. , Stegeman George I. 
Published: April 2011

AbstractModal Dispersion Phase Matching appears to be currently much better adapted to parametric mixing in polymeric material waveguides than Quasi Phase Matching. For second harmonic generation at telecommunication wavelengths, using organic materials should allow better performance than with ferroelectric crystals. Promising results are expected in view of theoretical expectations and continuously improving experimental past and current results.