bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impurity Gettering in MBE Grown Silicon
Authors: Nylandsted Larsen A. , KringhØj P. , Lundsgaard Hansen J. , Shiryaev S. Yu. 
Published: April 2011

AbstractA MBE growth procedure of epitaxial silicon layers is demonstrated which includes a special designed buried strained compositionally graded Si1−xGex layer. Upon thermal relaxation closed dislocation loops are formed in this Si1−xGex layer without altering the structure of the Si top layer. This dislocated layer is shown to getter contaminants in the Si top layer reducing the concentration of deep levels in this layer to ≈1 × 1012 cm−3.
Hydrogen-Induced Metastability of Polycrystalline Silicon
Authors: Nickel N. H. 
Published: April 2011

AbstractThe presence of H in polycrystalline silicon gives rise to new and hitherto unexpected phenomena. In this paper two of the most recent observations are reviewed: (i) Hydrogen-induced metastable changes of the dark conductivity due to the formation and dissociation of an electrically active H complex and (ii) the generation of acceptor states during prolonged exposure of poly-Si to monatomic H at elevated temperatures. The observed type conversion is clearly due to the diffusion of excess H from the plasma since it does not occur during exposure to other species such as oxygen.
Hydrogen Passivation of Shallow Dopants in Indium Doped Bulk CdTe
Authors: Gurumurthy Suma , Sreedhar A. K. , Bhat H. L. , Sundersheshu B. , Bagai R. K. , Kumar Vikram 
Published: April 2011

AbstractHydrogen passivation effects in In doped n-CdTe upon exposure to rf hydrogen plasma have been studied by electrical and photoluminescence measurements. Shallow dopant passivation of approximately an order of magnitude at 150°C and 50% at 170°C is observed. No visual damage is seen. Reverse bias annealing effects are also studied. Results are discussed.
Defect Studies in n-Type GaN Grown by Molecular Beam Epitaxy
Authors: Götz W. , Oberman D. B. , Harris J. S. 
Published: April 2011

AbstractGaN thin films grown by molecular beam epitaxy (MBE) were characterized by Hall effect measurements in the temperature range from 80 K to 500 K and by photoluminescence spectroscopy (PL) at 2 K and at 300 K. These films were grown by MBE utilizing either electron cyclotron resonance (ECR) plasma activated nitrogen gas or thermally cracked hydrogen azide (HN3) as the source of chemically reactive nitrogen. The electrical properties of the GaN films grown by ECR plasma assisted MBE were found to vary with growth parameters, dominated either by shallow donors with activation energies (ΔE)in the range between 10 meV and 30 meV or deep donor levels (ΔE; > 500 meV). GaN grown by (HN3) gas-source MBE exhibited metallic conduction and electron mobilities <1 cm2/Vs. However, these films displayed sharp photoluminescence lines at 3.360 eV and 3.298 eV and no deep level related luminescence, whereas only broad deep level related emission was observed in the PL spectra of the ECR plasma assisted MBE grown GaN films.
The Role of the Si-SiO2 (CVD) Interface in Degradation Effects for High-Speed Bipolar Transistors
Authors: Lü J.-Q. , Schöttl S. , Stefanov E. , Koch F. , Mahnkopf R. , Klose H. 
Published: April 2011

AbstractThe intent of the present work is to analyze device degradation and reliability in terms of their microscopic origins. The base-emitter junction of the advanced, “double-poly”, self-aligned bipolar transistor contacts the SiO2 sidewall spacer. During normal circuit operation, the base-emitter junction experiences a reverse bias which as a stress in time degrades the current gain of the transistor. Both a decrease of the gain, as well as an increase in the noise are observed. The forward base current increase as a function of stress time follows △IB ∼ tn. We present evidence that the defects are occurring at the Si-Si02 interface from perimeter to area comparisons. The weak temperature dependence of the forward base current in degraded transistors shows that trap-assisted tunneling current through the Si-SiO2 interface states is involved. The random-telegraph-signals observed for the first time in a silicon bipolar transistor are a direct identification of damage at the Si-SiO2 interface. 2D simulation of the potential and field near the interface allows us to show that damage can be expected.
Surface Morphology Investigation of Au and Pt Electroless Contact on ZnCdTe Crystal by Atomic Force Microscopy
Authors: Hu Zhiyu , Hu Zhihua , Chen K. T. , George M. A. , Burger A. , Collins W. E. 
Published: April 2011

AbstractGold and platinum metal contacts have been deposited on the cleaved and etched surfaces of ZnCdTe single crystals by “electroless” method from AuCl3, PtCl2 and PtCl4 aqueous solutions with different concentrations and deposition times. Atomic Force Microscopy (AFM) has been employed to reveal the surface morphology of metal contacts and it was found that for AuCl3 and PtCl2 solutions, the surface morphology and grain size are similar, and uniformly distributed. The surface morphology on contact made from PtCl4 shows a larger grain size, higher roughness and non-uniformity. The effect of different heat treatments to the surface morphology will be discussed.
Direct Wafer Bonding of Preamorphized Silicon Wafers.
Authors: Laporte A. , Sarrabayrouse G. , Benamara M. , Claverie A. , Rocher A. , Lescouzères L. , PeyreLavigne A. 
Published: April 2011

AbstractThis paper presents the comparison of the structural and electrical characteristics of Si/Si bonded interfaces depending on whether the surface layers were rendered amorphous by high dose ion implantation prior to annealing or not. While the general structure of the interfaces is the same when the wafers are preamorphized more precipitates are seen in the interface along with a few extended defects propagating into the volume. The most striking difference between both procedures is that the Spreading Resistance profile is more complicated in shape and difficult to master in the case of preamorphized wafers. Careful TEM analysis shows that only in this case the interfacial region is stressed in contrast with the fully relaxed structure obtained by direct bonding of crystalline wafers.For these reasons, there is little chance that the preamorphization technique will benefit to the bonding procedure of direct Si wafers.
Interaction Between EL5 and EL6 in Bulk GaAs
Authors: Shiraki Hiroyuki , Tokuda Yutaka , Sassa Koichi 
Published: April 2011

AbstractThe interaction between EL5 and EL6 in the n-type bulk GaAs have been observed by using isothermal constant-capacitance voltage transient spectroscopy (CCVTS). Each CCVTS spectrum of EL5 and EL6 was broader than a theoretical one expected for a single level, and was found to be consistently interpreted by two main trap components. With the increase of the filling pulse duration in a wide range, one component of EL6 decreased to about 50 % of its initial value, while one component of EL5 increased and saturated. This variation in peak heights could be reversed by controlling electron occupation fractions of EL5 and EL6 by application of two adjacent filling pulses. Such interaction between both levels was commonly observed in n-type bulk GaAs independent of carrier density.
Modification of Recombination Activity of Dislocations in Si and SiGe by Contamination and Hydrogenation
Authors: Kittler M. , Seifert W. , Higgs V. 
Published: April 2011

AbstractTemperature-dependent (80 … 300 K) measurements of dislocation recombination activity by the electron-beam-induced-current (EBIC) technique are reported. Controlled Cu contamination (ppb to ppm range), chemomechanical polishing and hydrogenation treatments were applied to alter dislocation properties. Increasing Cu level is found not only to increase the electrical activity of misfit dislocations in SiGe/Si structures at 300 K, but also to change its dependence on temperature. At low contamination, shallow centres control dislocation activity while deep centres are characteristic at higher Cu levels. Heavy Cu contamination results in very strong recombination activity which is attributed to precipitates. Chemomechanical polishing has an effect which is analogous to medium Cu contamination. Hydrogenation was found to passivate recombination activity at 300 K, but did not show pronounced effects on activity at low temperature.
Studies of Exchange Coupling in Fe/Cu/Fe(001) “Loose Spin” Structures
Authors: Kowalewski M. , Heinrich B. , Totland K. , Cochran J.F. , Govorkov S. , Atlan D. , Myrtle K. , Schurer P. 
Published: April 2011

ABSTRACTThe interlayer exchange coupling has been studied in two trilayer structures:(a) 5.7Fe/5Cu/1FecCu1-c/5Cu/10Fe(001), where c=0.0, 0.1, 0.2, 0.45 0.60(b) 5.7Fe/5Cu/1CrcCu1-c/5Cu/10Fe(001), where c=0.1, 0.45, 0.8 and 1.0.The intention of these studies was to identify the role of Fe and Cr atoms in the alloyed FecCu1-c and CrcCu1-c layers on the direct interlayer coupling which is facilitated by the Cu valence electrons. FMR, BLS and MOKE studies were used to determine the interlayer exchange coupling. Mossbauer spectroscopy was used to identify the magnetic state of the Fe atoms in the alloyed layer. The results showed that the presence of foreign atoms inside the Cu spacer significantly decreased the bilinear antiferromagnetic coupling between the Fe layers. In the low concentration limit the Fe and Cr atoms behaved in a similar manner. A significant difference was found in the high concentration limit where the Fe atoms start to be partially magnetically ordered.
Reducing Intergranular Magnetic Coupling by Incorporating Carbon into Co/Pd Multilayers
Authors: Liu Wenhong , Morris Jonathan , Payne Alex , Lairson Bruce 
Published: April 2011

ABSTRACTThe ideal magnetic switching mechanism for many types of data storage, including hard disk recording, is isolated domain coherent rotation (Stoner-Wohlfarth switching). However, in typical Pd/Co multilayers with high coercivity, the dominant switching mechanism is domain wall motion, which causes noise in the read back signal. We show that the proper addition of elements, such as carbon, into Pd/Co multilayers reduces the coupling between adjacent magnetic domains. The reduction of magnetic coupling reduces the length scale over which incoherent switching occurs.
Magnetic Properties of Epitaxial Mbe-Grown thin Fe3O4 Films on MgO (100)
Authors: Van Der Heijden P.A.A. , Hammink J.J. , Bloemen PJ.H. , Wolf R.M. , Van Opstal M.G. , Van Der Zaag P.J. , Jonge W.J.M. De 
Published: April 2011

ABSTRACTCoherent epitaxial Fe3O4 layers in the range of 0 to 400 Å have been grown by molecular beam epitaxy on single crystal MgO(100) substrates. The magnetic properties were studied by local magneto-optical Kerr effect experiments on a wedge shaped Fe3O4 layer, by ferromagnetic resonance and SQUID. The results show that the magnetic behavior of the Fe3O4 thin films resembles bulk Fe3O4 in the investigated thickness range.
Magnetic Properties of FEXMN1-X/IR(100) Superlattices.
Authors: Fischer H. , Andrieu S. , Bauer Ph. , Piecuch M. 
Published: April 2011

ABSTRACTWe have produced pseudomorphic FexMn1-x/Ir(100) superlattices having different stoichiometry (0.8 ≥ x ≥ 0.3). The alloy crystalline structure is body centered tetragonal with a c/a ratio between 1.18 and 1.26. Iron rich alloys are ferromagnetic when the corresponding bulk alloys are antiferromagnetic. Manganese rich alloys are certainly antiferromagnetic according to bulk magnetization measurements and Mössbauer effect results. The transition from a ferromagnet with a vanishing moment when x = 0.5 to an antiferromagnet is associated with a volume expansion.
Determination of Spin-Dependent Scattering Parameters of NiFe/Cu and Co/Cu Multilayers
Authors: Lenczowski S.K.J. , Gijs M.A.M. , van de Veerdonk R.J.M. , Giesbers J.B. , de Jonge W.J.M. 
Published: April 2011

ABSTRACTWe present magnetoresistance (MR) data of high-vacuum magnetron sputtered NiFe/Cu multilayers (NiFe=Ni80Fe20) grown on Si(100) substrates with a Cu buffer layer and compare these with earlier results on Co/Cu(100) multilayers [1]. Measured MR values are directly proportional to the antiferromagnetically coupled fraction in the multilayers. Extrapolating to full antiparallel alignment, we can make a reliable comparison of the MR with the magnetoresistance model of Levy, Zhang, and Fert [2,3]. For the NiFe/Cu multilayers the deduced spin-asymmetry parameters are for interface and bulk scattering, respectively. Although much smaller than in our Co/Cu multilayers, , it is still the spin dependence of the interface scattering that is the main cause for the large MR values.
Improved Thermal Stability of Gmr Spin Valve Films
Authors: Mcmichael R. D. , Egelhoff W. F. , Ha Minh 
Published: April 2011

ABSTRACTIn order to improve the thermal stability of magnetic multilayer “spin valve” structures, we have measured the magnetic and magnetoresistive properties of a number of samples with the general structure of NiO/Co/Cu/Co/Cu/Co/NiO as a function of annealing time at 250 °C. The magnetoresistance (MR) of the samples annealed in air decreases proportionally to the square root of the annealing time. For samples annealed in a vacuum, the decrease in magnetoresistance is reduced, but not eliminated. Magnetometry of a vacuum annealed NiO/Co/NiO sample shows a magnetization reduction and a coercivity increase which suggest oxidation of the NiO-biased “outer” Co layers of the spin valve structure. For increasing NiObiased Co layer thickness, we show enhanced thermal stability and even increasing MR with annealing time for samples with the thickest outer Co layers.
Improvement of Gmr in NiFeCo/Cu Multilayers by a Layer - by - Layer Magnetic Field Sputtering
Authors: Saito K. , Yanagida Y. , Obi Y. , Itoho H. , Fujimori H. 
Published: April 2011

ABSTRACTNiFeCo/Cu multilayers fabricated by an improved magnetic field sputtering were investigated in order to achieve the soft GMR (giant magnetoresistance) with a high sensitivity at low magnetic fields. A magnetic field was applied to the film during sputter-deposition, and its field direction was changed alternately from layer to layer. Such an alternate field sputtering is called hereafter layer-by-layer magnetic field sputtering. The best GMR characteristics (large MR at low magnetic fields) were achieved when the angle between the directions of magnetic field applied to neighboring two magnetic layers was 90°. As one of the speculation, it has been considered that the result is attributed to the induced composite magnetic anisotropy which causes the magnetization to occur more dominantly by spin rotation than by domain wall movement.
In Situ Study of The Exposure of Polycarbonate to an Argon Plasma
Authors: Vallon S. , Drevillon B. , Poncin-Epaillard F. , Rostaing J. C. 
Published: April 2011

ABSTRACTThe exposure of polycarbonate to an argon plasma is studied using in situ ellipsometry from the UV to the IR, nuclear magnetic resonance and light scattering measurements. An increase in the refractive index and the existence of two populations of different molecular weights show that structural changes occur in the polymer. They are correlated with modifications at the polymer unit scale, such as formation of new polar groups and decrease in dimethyl groups. Two simultaneous reaction mechanisms must be considered to account for these changes. The adhesion of a silica layer on treated polycarbonate is then discussed.
Interfacial Water and Adhesion Loss of Polymer Coatings on a Siliceous Substrate
Authors: Nguyen T. , Byrd E. , Alsheh D. , McDonough W. , Seiler J. 
Published: April 2011

ABSTRACTWater is often the main cause of adhesion loss of a polymer coating/substrate system. The buildup of the interfacial water layer and the loss of adhesion of polymer-coated siliceous substrates exposed to liquid water has been investigated. The thickness of the interfacial water layer was measured on epoxy-coated SiO2-Si prisms using FTIR-multiple internal reflection (FTIR-MIR) spectroscopy. Adhesion loss on flat siliceous substrates was determined by a wet peel test on epoxy-coated SiO2-Si wafers and adhesion loss of composites was obtained by measuring the interlaminar shear strengths of epoxy/E-glass fiber composites. Both untreated and 0.1 % silane-treated substrates were used. Little water was observed at the interface of the silanetreated samples but about 10 monolayers of water have accumulated at the interface of the untreated samples after 100 h of exposure to 24°C water. Untreated, flat substrates lost most of their bonding strengths within 75 h of exposure but silane-treated specimens retained 80% of their adhesion after 600 h of exposure to 24°C water. Adhesion loss of untreated composites immersed in 60°C water was greater than that of treated samples; however, the rate of loss of both silanetreated and untreated composites was much lower than that of flat substrates. Adhesion loss was found to follow the same trend as interfacial water buildup.
Controlled Nitrogen-Atom Incorporation At Si-SiO2 Interfaces in Mis Devices
Authors: Lee David R. , Parker Christopher G. , Hauser John R. , Lucovsky Gerald 
Published: April 2011

ABSTRACTWe have developed a new pre-deposition, remote N2O plasma oxidation treatment for forming nitrided SiO2 films and report here the quality and reliability of devices fabricated with these films. The Si-dielectric heterostructure process has been separated into three independently-controlled steps: i) final Si surface cleaning, and Si – SiO2 interface formation by plasma-assisted oxidation/nitridation at 300 °C; ii) remote plasma-enhanced chemical vapor deposition of nitrided dielectrics, also at 300 °C; and iii) optional post-deposition rapid thermal annealing. This paper focuses on the first step in which the oxidation has been performed with O2, N2O or N2O / O2 mixtures to control the amount of N-atoms at the interface, Nint. We show that the incorporation of up to ∼ 1015 N-atoms/cm2 at the Si-SiO2 interface by this process has no effect on threshold voltage, Vt, or peak channel transconductance, gm,max, but does improve high-field gm and transistor drive current. Improved resistance to Vt and gm,max degradation during hot-carrier stressing of sub-micron devices is also discussed.
Advanced Technology Processing and State-of-the-art Solutions to Cleaning, Contamination Control, and Integration Problems
Authors: Abadeer W. W. , LeBlanc A. , Kluwe A. , Schulz P. , Vollertsen R. , Penka V. , Nadahara S. , Antreasyan A. , Cote D. , Cote W. , Levy M. , Akatsu H. , Ludeke R. 
Published: April 2011

ABSTRACTUltraclean semiconductor processes were developed for ULSI technologies to significantly reduce metallics, foreign materials, and to preserve silicon surface morphology. State-of-the-art detection techniques (Elymat, TXRF, VPD, and SPV) were implemented in all critical process sectors. Acceptable levels of metallic contamination were derived from previous experience and from published work on this subject relating metallic contamination levels to gate oxide reliability and retention time.A comprehensive diagnostic/characterization system was utilized in evaluating a wide variety of test structures emulating key device process interactions. Advanced techniques were employed for measurement of reliability and surface morphology. Also root causes for all integration problems are identified.
Wafer Cleaning Influence on the Roughness of the Si/SiO2 Interface
Authors: Munkholm A. , Brennan S. , Goodbread Jon P. 
Published: April 2011

ABSTRACTThe roughness of the Si/SiO2 interface has a great impact on the electrical properties of the gate-oxide in integrated circuits and consequently it is a large concern for the semiconductor industry. As the thickness of the oxide is decreased, the role of the roughness becomes more critical for the device. The nature of a buried interface prohibits the use of commonly used surface techniques. By the use of crystal truncation rod (CTR) x-ray scattering, it is possible to get information on the termination of the bulk silicon in a nondestructive fashion. The authors have investigated the influence of different cleanings on interfacial roughness using synchrotron radiation-based CTR-scattering. In particular, we looked at silicon(001) wafers both before and after the growth of a 1000Å thermal oxide. The results show that the use of HF during cleaning results in a smoother interface between silicon and its native oxide. Due to smoothing of the interface during the oxidation process, the difference between the various cleaning methods becomes less significant for these thick oxides.
Mechanisms of Excimer Laser induced Positive Ion Emission From Ionic Crystals
Authors: Dickinson J. T. , Shin J-J. , Langford S. C. 
Published: April 2011

AbstractThe energy distributions of positive ions produced by exposing single-crystal MgO to pulsed 248 nm excimer laser light at fluences of 200-1200 mJ/cm2 were determined by combined quadrupole mass spectrometry and time-of-flight techniques. the dominant ionic species is Mg+, although small amounts of Mg2+, MgO+, and Mg2O+ are also observed. IN particular, theMg+ and Mg2+ energy distributions each show two broad peaks, with the energies of the Mg2+ peaks at significantly higher energies. Ion trajectory simulations (accounting for Coulomb forces only and assuming no surface relaxation) suggest that Mg2+ adsorbed at sites directly atop surface F-centers (oxygen vacancies with two trapped electrons) would be ejected upon photo-ionization of the F-center. the experimentally observed Mg2+ kinetic energies agree well with the energies predicted by the simulation.
Ion-Assisted Pulsed Laser Deposition of BN Films
Authors: Doll G. L. , Chance D. C. , Salamanca-Riba L. 
Published: April 2011

AbstractBoron nitride films grown by ion-assisted pulsed laser deposition have been characterized by infrared absorption, auger electron pectroscopy, and transmission electron microscopy. Elemental bonding and the crystallinity of BN films grown in three nitrogen ion energy regimes:high (2500 eV), low (700 eV), and without ions (0 eV) are examined, and the results interpreted within the framework of a compressive stress mechanism for cBN film growth.
Carbon Nitride Films Using a Filtered Cathodic ARC
Authors: Camphausen Scott.M. , Tucker D.A. , Bruley J. , Cuomo J.J. 
Published: April 2011

AbstractCarbon nitride films were deposited on sapphire, silicon, molybdenum and quartz substrates using a filtered cathodic arc with a radio frequency (rf) inductively coupled plasma, Previous researchers have used the cathodic arc but obtained low concentrations of nitrogen in their films. the addition of the rf coils was used to enhance dissociation of molecular nitrogen in the vicinity of the substrate. the resultant films were analyzed for chemical bonding and composition by several methods including Electron Energy Loss Spectroscopy (EELS), augei Electron Spectroscopy (AES), and infrared spectroscopy (IR). EELS and IR provided bonding information and showed that the films were largely composed of sp2 bonding and contained carbon-nitrogen double bonds, respectively. also, chemical composition of the films was determined using aES, IR and EELS.
High-Rate Deposition of Thin Films by High-Intensity Pulsed Ion Beam Evaporation
Authors: Zakoutayev A.N. , Remnev G.E. , Ivanov Yu.F. , Arteyev M.S. , Matvienko V.M. , Potyomkin A.V. 
Published: April 2011

AbstractA high-intensity ion beam (500 keV, current density 60 - 200 a/cm2, power density (0.25 - 1) • 108 W/cm2, pulse duration 60 ns, pulse repetition rate 4-6 mur-1) was used to deposit thin metal and carbon films by evaporation of respective targets. the instantaneous deposition rate was 0.6 - 5 mm/s. the films were examined using transmission electron microscopy and transmission electron diffraction. the metal films had a poly-crystalline structure with the grains measuring from 20 to 100 nm, the lower the melting point the greater the grain size. the carbon films contained 25 - 125 nm diamonds. the ablation plasma was studied employing methods of pulsed spectroscopy.