bluuebunny/crossref_metadata_2025_split huggingface dataset:
Defects In Erbium/Oxygen Implanted Silicon
Authors: Duan X. , Palm J. , Zheng B. , Morse M. , Michel J. , Kimerling L. C. 
Published: April 2011

AbstractA systematic study of defects in the Er/O implanted silicon was conducted using TEM, HRTEM and SIMS. Defect-free material was obtained after the annealing of 400 keV Er+ implanted (100)Si. In sharp contrast, several forms of secondary defects consisting of dislocations, dislocation loops and precipitates were induced upon annealing at different temperatures in the 4.5 MeV implanted (100)Si sample. The isothermal evolution of the defects and reactions between dopants and defects were studied. Oxygen tends to segregate into the dislocation loop zones, where platelet precipitates with habit planes of {111} were found. Following dissociation of oxygen and erbium, plate-like Er precipitates were generated, which are most likely ErSi2 with a habit plane of {111}
Room Temperature Electroluminescence From D1 Dislocation Centers In Silicon
Authors: Sveinbjörnsson Einar Ö , Weber Jörg 
Published: April 2011

AbstractWe report on electroluminescence at room temperature from forward biased n+-p silicon diodes containing high densities (108-109 cm−2) of dislocations at the junction interface. In addition to electroluminescence from band-to-band transitions, we observe a signal arising from the well known dislocation center Dl peaked at ∼1.6 μm (0.78 eV). The Dl electroluminescence intensity at room temperature increases linearly with current density with no observable saturation as long as sample heating is avoided. The quenching of the D l luminescence between 4 K and room temperature is highly sensitive to metal impurities which introduce competitive non-radiative recombination centers. The external power efficiency of the DI electroluminescence was estimated to be of the order of 10−6.
Hall Effect Measurements On SixGe1−x Bulk Alloys
Authors: Mchedlidze T. , Yonenaga I. 
Published: April 2011

AbstractCarrier transport measurement results for SixGe1−x bulk alloys with 0.03≤x≤0.9, grown by the Czochralski method are presented. Both monocrystalline (x=0.03 and x=0.23) and polycrystalline (x=0.12, 0.25, 0.4, 0.5, 0.75, 0.9) samples were analyzed. In all samples additional charge carriers were created during growth or/and cooling of crystals. With n-type starting materials only alloy with x=0.9 revealed n-type conductivity, all other alloys were of ptype. Creation of acceptors in the SixGe1−x alloy grown by Czochralski method is maximal for 0.4≤x≤0.75.
Residual Impurities And Transport Properties of High Purity Movpe Gaas
Authors: Steude G. , Hofmann D. M. , Drechsler M. , Meyer B. K. , Hardtdegen H. , Hollfelder M. 
Published: April 2011

AbstractHigh purity GaAs grown by metal organic vapor phase epitaxy (MOVPE) using nitrogen as a carrier gas has been studied by optically detected cyclotron resonance (ODCR) at microwave and far infrared frequencies. Upon variation of the experimental parameters such as sample temperature, optical excitation density and microwave power the residual ionized (donor) and neutral (acceptor) impurity concentrations can be estimated, they are 2×1012 cm−3 and 5×1013 cm−3, respectively. The luminescence results indicate C to be the dominant residual acceptor. The residual donors were identified as S, Se, Sn from the observation of the internal 1s - 3p×105 cm2/Vs.
Influence Of The Temperature And The Light Intensity On The Metastable Transformation Of EL2
Authors: Alvarez A. , Jimenez J. , Gonzalez M. A. , Chafai M. 
Published: April 2011

AbstractThe temperature dependence of the metastable transformation of EL2 is explained in terms of the thermal emission of holes from the actuator level, VA. A model including the thermal release of holes from this level is presented. The numerical solution allows to account for the low photoquenching efficiency above 80 K in an accurate way. The existence of this level was postulated on the bases of the electric compensation and the temperature dependence of the metastable transformation of EL2 in semiinsulating GaAs. This level allows a complete description of the driving mechanism of the metastable transformation of EL2.
Diffusion Process Of Interstitial Atoms In Inp Studied By Transmission Electron Microscopy
Authors: Ohno Y. , Takeda S. , Hirata M. 
Published: April 2011

AbstractIt is found that interstitial agglomerates are formed uniformly in an irradiated area of InP by annealing at the temperature above 700 K after 200 keV-electron irradiation. TEM observation shows that the number density of interstitial atoms in the agglomerates reached a maximum value when the growth of all the agglomerates stopped. The final density did not depend on annealing temperature but on electron dose, and it increased quadratically with electron dose up to 2×1022 cm−2. In order to explain the experimental results, we have proposed a new model that the agglomerates are formed by thermal diffusion and agglomeration of interstitial-pairs, i.e. Ini-Pi interstitial-pairs. From the analysis, the migration energies for the pairs are estimated to be 1.52 eV. The onset temperature for the diffusion of the pairs is estimated as 550 K.
Electrical And Structural Properties Of LT-GaAs: Influence Of As/Ga Flux Ratio And Growth Temperature
Authors: Luysberg M. , Sohn H. , Prasad A. , Specht P. , Fujioka H. , Klockenbrink R. , Weber E. R. 
Published: April 2011

AbstracThe deposition of GaAs by MBE at low temperatures results in a material of unique properties. However, up to now the control and understanding of the electrical and structural properties are unsatisfactory. To investigate the influence of growth parameters on the formation of point defects and electrical properties, the substrate temperature and the As/Ga flux ratio were systematically varied. In a well defined parameter range the lattice expansion was found to be dominated by the formation of As antisite defects. After annealing a high resistivity is obtained independent of the growth conditions. A strong influence of the growth temperature on the band conduction mechanism is observed, whereas a variation of the As/Ga flux ratio induces only slight changes of the temperature dependence of the conductivity.
Influence Of Donor, Acceptor, And Isovalent Impurity Doping On Arsenic Excess And Point Defects In Low Temperature Grown GaAs
Authors: Chaldyshev V. V. , Kunitsyn A. E. , Faleev N. N. , Preobrazhenskii V. V. , Putyato M. A. , Semyagin B. R. , Tretyakov V. V. 
Published: April 2011

AbstractWe show that in contrast to Si donor and Be acceptor doping, isovalent In impurity doping enhances arsenic excess in the GaAs films grown by molecular beam epitaxy at low temperature. This effect is due to an increase in the concentration of arsenic antisite defects. Gallium vacancy related defects are detected only in the samples annealed at high temperature. Their concentration is found to be higher in the indium-free material than in the indium doped one
S-Doped GaInAs Grown By Chemical Beam Epitaxy: Electrical And Structural Characterization
Authors: Paloura E. C. , Petkos G. , Goodhew P. J. , Theys B. , Chevallier J. 
Published: April 2011

AbstractWe report on the electrical and structural characterization of sulfur (S) doped Ga0.73In0.27As layers, grown on SI (001) GaAs substrates by chemical beam epitaxy. The room temperature free electron concentration is 2×1017cm−3 while the corresponding value of mobility is 3400 cm2V−1 s−1. The epilayer is characterized by a deep trap, which could be attributed to the electrical activity of dislocations, with an activation energy of 0.59 eV and a capture cross section 6×10−15 cm2. TEM analysis shows that the GaInAs/GaAs interface is characterized by dislocation lines and loop-like configurations which could be attributed to climb movement by point defect absorption or emission. Annealing at 420°C (Ar ambient for 5 min) does not alter the carrier concentration (n) and mobility (μ) significantly. The invariance of n and μ, even though the temperature should be high enough to dissociate any Satomic hydrogen complexes, indicates that the number of hydrogen-S donor complexes in the as-grown material is small compared with the donor concentration. Finally, the effect of intentional atomic hydrogen diffusion is discussed.
Deep Centers Influence On Photoresponse Characteristics In High-Resistivity ZnSe
Authors: Korotkov V.A. , Bruk L.I. , Simashkevich A.V. , Gorea O.S. , Kovalev L.E. , Malikova L.V. 
Published: April 2011

AbstractThe photocurrent peak after preliminary optical excitation with specific wavelength in high resistivity (ρ≍1012 Ω∗cm), unintentionally doped ZnSe monocrystals was observed. To study photocurrent “flash” phenomenon, the photocurrent relaxation spectra, photon-capture crosssection (PCCS) spectra and photo-electron paramagnetic resonance (photo-EPR) were investigated. Two-levels model involving the recombination of an S-center and an acceptor A has been developed to obtain the relation between recombination probability and instantaneous photocurrent value. The S-centers ionization energies (1.06eV and 1.14eV from the bottom of the conduction band) and charge carriers life times were determined. The acceptor's positions in ZnSe band gap are equal to 2.05, 2.11, 2.16 and 2.21eV from the bottom of the conduction band. The photocurrent and PCCS “flash” nature as well as complicated photo-EPR are associated with the relaxation of S-centers attributed to Fe ion in the band gap of semi-insulated ZnSe.
The Microscopic Structure Of Shallow Donors In Silicon Carbide
Authors: Spaeth J.-M. , Greulich-Weber S. , März M. , Kalabukhova E. N. , Lukin S. N. 
Published: April 2011

AbstractThe electronic structure of nitrogen donors in 6H-, 4H- and 3C-SiC is investigated by measuring the nitrogen hyperfine (hf) interactions with electron nuclear double resonance (ENDOR) and the temperature dependence of the hf split electron paramagnetic resonance (EPR) spectra. Superhyperfine (shf) interactions with many shells of 13C and 29Si were measured in 6H-SiC. The hf and shf interactions are discussed in the framework of effective mass theory. The temperature dependence is explained with the thermal occupation of the lowest valley-orbit split A1 and E states. It is proposed that the EPR spectra of P donors observed previously in neutron transmuted 6H-SiC at low temperature (<10K) and high temperature (>60K) are all due to substitutional P donors on the two quasi-cubic and hexagonal Si sites, whereby at low temperature the E state is occupied and at high temperature the A1 state. The low temperature spectra are thus thought not to be due to P-vacancy pair defects as proposed previously.
Fluorinated Amorphous Carbon Thin Films Grown from C4F8 for Multilevel Interconnections of Integrated Circuits
Authors: Endo Kazuhiko , Tatsumi Toru , Matsubara Yoshihisa , Horiuchi Tadahiko 
Published: April 2011

AbstractFluorinated amorphous carbon thin films (a-C:F) for use as low-dielectric-constant interlayer dielectrics were deposited by helicon-wave plasma-enhanced chemical vapor deposition using fluorocarbon compounds as a source material. The a-C:F films could be grown from C4F8 at a high deposition rate (above 400 nm/min) and they were thermally stable up to 300°C. The addition of bias power to the substrate made it possible to completely fill gaps in the wiring (space 0.35 μm, height 0.65 μm) with the a-C:F film. To protect the a-C:F film during further processing, we deposited a SiO2 film to add mechanical strength and resistance to the oxygen plasma used to remove resist materials. The adhesion between the a-C:F and SiO2 films was dramatically improved by inserting an adhesion promoter consisting of a-C:H and Si-rich SiO2.
Properties of Plasma Oxynitride Films On Strained Sige
Authors: Mukhopadhyay M. , Bera L.K. , Ray S.K. , Maiti C.K. 
Published: April 2011

AbstractThe electrical properties of oxynitride films on strained SiGe grown and deposited, respectively, using a N2O and a combination of N2O and hexamethyldisilazane (HMDS) plasma are reported. X-ray photoelectron spectroscopy (XPS) analysis of the N2O grown films have shown the incorporation of N at the oxide interface without any Ge segregation. The hole confinement in accumulation in SiGe/Si heterostructure with 90 Å N2O oxynitride film has been observed by C-V measurements. Plasma reoxidation of N2O grown dielectric films has resulted in significant improvement of electrical properties. Oxynitride films deposited using PECVD of HMDS have shown comparatively inferior properties. Films deposited from a mixture of N2O and HMDS, exhibit the highest value of Dit (1x1012 cm-2eV-1), probably due to higher amount of nitrogen incorporation at the interface. The charge trapping behavior of both the grown and deposited films have been studied. The effect of addition of NH3 in HMDS plasma and N2O oxidation prior to HMDS PECVD on the charge trapping behavior has been studied.
Characterization of Pecvd Sin Films by Spectroscopic Ellipsometry
Authors: Brierley Steven K. , Nguyen Lan 
Published: April 2011

AbstractPlasma-enhanced chemical vapor deposition (PECVD) silicon nitride films deposited on both GaAs and Si substrates have been characterized by spectroscopic ellipsometry. The results indicate that such films consist of three constituents: Si3N4, voids, and amorphous silicon (α-Si). In addition, it is also observed that for typical deposition conditions there is an intervening layer of α-Si (on the order of 50–100 Å) between the nitride film and the semiconductor substrate. The thickness of this a-Si layer is found to depend on both the stoichiometry and the growth time of the nitride layer, leading to the conclusion that it is a result of excess Si diffusing from the growth surface through the nitride layer.
Chloroethane Physisorbed on Hydrogenated Si(111): A Test System for the Evaluation of Core Level XPS Assignment Rules at Si/SiO2 Interfaces
Authors: McFeely F. R. , Zhang K. Z. , Banaszak Holl Mark M. 
Published: April 2011

AbstractWe briefly review the controversy concerning the proper methodology for the assignment of soft x‐ray photoemission Si 2p core levels at Si/SiO2 interfaces. Evidence for Second nearest neighbor effects in the photoemission spectra of analogous free molecules in the gas phase are surveyed for the purpose of placing this controversy within a wider context. Physisorption experiments have been performed to inquire whether the second nearest neighbor effects found in free molecules are in any way reduced in their magnitude owing to the proximity to the highly polarizable Si surface. No evidence for such a diminution have been found.
Simulation of Wiring Capacitance For Sub-Quarter-Micron Ulsi Devices and Its Application
Authors: Hasegawa T. , Kobayashi T. , Kadomura S. , Aoyama J. 
Published: April 2011

AbstractWiring capacitance in a multilevel interconnecting structure for sub-quarter-micron ULSI devices has been studied using a simulator called SENECA1), which is developed by the Technical University of Vienna and Sony corporation, for optimizing the structure with low dielectric constant materials as interlevel dielectric layers. The simulation results suggest that an optimized structure model should have an ILD(Inter-Level Dielectrics) thickness of 0.7μm and a metal thickness of 0.4μm for sub-quarter-micron ULSI devices. The application of the low dielectric constant materials to the ULSI devices is examined and also discussed with focusing on feasibility and reliability issues. Calculated wiring capacitance is compared with actual capacitance based on the optimized structure. The 33.2% reduction of capacitance is obtained with using an organic film with dielectric constant of 2.4 in excellent accordance with the simulation.
Evidence for Cooperative Oxidation of Mocvd Precursors Used in BaxSr1‐x TiO3 Film Growth
Authors: Glassman Timothy E. , Bhandari Gautam , Baum Thomas H. 
Published: April 2011

AbstractMetal ß‐diketonate complexes are common precursors for chemical vapor deposition (CVD) of a wide variety of thin‐film materials. Liquid delivery CVD has been used to deposit high dielectric constant materials, such as BaxSr1‐xTiO3.[1] This method relies upon volumetric metering of organic soluble precursors, “flash” vaporization to transport the reactants into the gas‐phase and subsequent thermal decomposition onto the heated substrate. This approach enables the precise control of deposited film stoichiometry. In this study, simultaneous thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to examine the transport and thermal decomposition properties of M(thd)2 (M = Sr, Ba) and Ti(O‐i‐Pr)2(thd)2. In an argon atmosphere, vaporization and transport are observed below 400 °C. In oxidizing atmospheres, such as nitrous oxide and oxygen, decomposition leads to metal carbonate formation as evidenced by both the mass balance and x‐ray diffraction patterns of the residual solids. In the presence of an equimolar amount of the Ti precursor, the formation of carbonates is not observed and oxides are produced at greatly reduced temperatures. Based upon this data, a cooperative oxidation mechanism is proposed which results in “clean” precursor decomposition and BST oxide formation at temperatures near 500 °C.
Comparison of (L)M(thd)2 (M = Mg, Ca, Sr, Ba; L = Tetraglyme, Pmdeta) Precursors for High K Dielectric Mocvd
Authors: Bhandari G. , Glassman T. E. , Studebaker D. B. , Stauf G. , Baum T. H. 
Published: April 2011

AbstractHigh-purity alkaline earth ß-diketonate compounds such as [M(thd)2]x (M = Mg, Ca, Sr, Ba) have been utilized for liquid delivery MOCVD.[1] The “parent” compounds are oligomeric species with bridging ß-diketonate ligands and display both limited volatility and thermal instability. To enhance the precursor transport and film growth rates, Lewis base ligands are used to produce mononuclear precursors.[2] Lewis base coordinated metal (ß-diketonates) also exhibit increased solubilities in organic solvents. In this study, two classes of Group II ß-diketonates were compared; thermal stability and transport were evaluated by simultaneous thermal analyses, using both thermogravimetric (TGA) and differential scanning calorimetry (DSC). Liquid delivery and vaporization were evaluated in an “experimental” liquid delivery system and preliminary film growth, including electrical film properties were measured. The identity of the Lewis base and Group II precursor molecular structure as relates to liquid delivery vaporization and CVD film growth of BaxSr1–xTiO3 are described.
Atomic Bonding in Amorphous Alloys Based on Carbon, Nitrogen, and Hydrogen: A Thermodynamic Approach
Authors: Efstathiadis H. , Akkerman Z. , Smith F. W. 
Published: April 2011

AbstractA thermodynamic model previously outlined for the prediction of the bonding in amorphous hydrogenated carbon-nitrogen alloy films (a-CxNyHz), is extended here to include the effects of enthalpy and entropy. Predictions are presented for the bonding of tetrahedral C(sp3), trigonal C(sp2), pyramidal N(sp3), and trigonal N(sp2) atoms in the alloy as well as the bonding of H to these atoms. When bond energies alone are considered, it is predicted that typical a-CxNyHz films will undergo a phase separation into graphitic regions containing C(sp2) atoms, and C(sp2)-N(sp3)-H groups, and diamond-like or polymeric regions containing only C(sp3) and H atoms. When the effects of entropy are also included, phase separation is eliminated and C(sp3)-C(sp2), C(sp2)=N(sp2), and C(sp2)-N(sp2), bonds are also predicted to be present. The model predictions are compared with experimental results for typical amorphous a-CxNyHz alloys that have been prepared via plasma-enhanced chemical vapor deposition from mixtures of nitrogen and acetylene. In a film with y=0.07 the carbon atoms sp3/sp2 ratio is predicted to be 0.7, while 80% of N atoms are predicted to be trigonal N(sp2) atoms.
Comparison of Gate Oxide Processing Techniques for Thin Dielectric Films
Authors: Schay Pat , Lin Fuyu , Ajuria Sergio , Stih John 
Published: April 2011

AbstractThis paper focuses on establishing a baseline for thin dielectric processes including: low temperature, dilute, stacked (TEOS), oxynitride, and high temperature annealed (grow‐anneal‐grow) oxidation. 105Å (total thickness) gate dielectrics were grown or deposited for this study. The stack oxide showed the highest Vbd yields for both large‐area and edge‐intensive capacitors, but the poorest Qbd. The N2O oxide yielded mediocre Vbd and Qbd. The low temperature and dilute oxides showed early breakdowns, but acceptable Qbd. 900°C thermal gate oxide showed slightly better average Vbd than low temperature and dilute oxides but comparable Qbd. The high temperature annealed oxide appears to have the best electrical performance, but the worst uniformity.
Measurement of Arsenic Emission from Doped Czochralski Silicon Crystal Growing Operation
Authors: Sinha D. , Carlson C. , Homyak Andy , Hunter Elias 
Published: April 2011

AbstractThe level of arsenic from the effluent of a crystal grower was measured at different phases of the silicon crystal growth operation which includes arsenic doping, crystal body growth, burn‐in, and post burn‐in periods. Measurement of arsenic levels were made in the discharge water used as the sealing liquid for the liquid ring vacuum pump used for process effluent discharge. Gas phase measurements were also performed for both particulate arsenic as As2O3 as well as for compounds of arsenic in vapor phase as AsH3. Results of these analyses provided important information for developing strategy for emission treatment and control, reducing arsenic exposure to personnel and evaluating the feasibility for recycling argon used in the crystal growing process.
An Integrated Chemical-Microbiological Approach for the Disposal of Waste thin Film Cadmium Telluride Photovoltaic Modules
Authors: Paknikar K. M. , Rajwade J.M. , Pethkar A. V. , Goyal D. J. , Bilurkar P.G. , Mate N. V. 
Published: April 2011

AbstractThe paper describes a novel chemical-microbiological method for the selective removal of cadmium, tellurium and silver from the thin film CdTe photovoltaic modules. The chemical component of the process utilizes dissolution of metals with nitric acid. The metal solution is subjected to selective biosorption of silver and cadmium by passing through biosorbent columns. The adsorbed cadmium and silver are desorbed and recovered by chemical precipitation. Tellurium in solution coming out of the biosorbent columns is converted microbiologically to its metallic form in a bioreactor. The combined chemical-microbiological treatment ensures recovery of silver, cadmium and tellurium with 86%, 80% and 99% efficiency, respectively. The treated waste can be discharged safely in the environment.
Next Generation Processes and Equipment that Lead to Positive Environment, Safety, and Health Impacts
Authors: Pei Phyllis , Kerby H. Ray 
Published: April 2011

AbstractThe technology development needed to support the continuous improvement of Environment, Safety, and Health (ESH) characteristics of semiconductor manufacturing facilities is changing as strategies for source reduction and incident prevention and more refined schemes for assessing ESH improvement emerge. This paper summarizes the changes taking place in ESH management structure and focuses on examples of current technology development to satisfy the new model of ESH execution.