bluuebunny/crossref_metadata_2025_split huggingface dataset:
Defects and Future Silicon Technology
Authors: Palm J. , Kimerling L.C. 
Published: April 2011

AbstractThe interaction between device technology and the control of defects has been strong since the first transistor. The rapid and unparalled development of this technology can be monitored by changes in device size and process complexity, or reciprocally, in defect density. In the future the emphasis on computation functionality will shift to imaging and learning. In addition high volume manufacturing will cast an emphasis on capital cost, yield, effluent control and safety. These foci require the development of new sensitive defect assessment tools, the modelling of complex defect systems and the understanding of defect properties on the atomic scale. We shall illustrate this interplay between technology and materials science by topics in ULSI circuits, silicon photovoltaics and silicon microphotonics. For ULSI the control of both bulk and surface defects is decisive. The physical chemistry at the silicon surface plays a key role in metal contamination. We shall discuss the use of RF-PCD for in-line monitoring and investigation of reaction kinetics. Silicon for low cost, photovoltaic applications confronts problems involving complex defect systems, but comparatively simple processes. The goal is to optimize growth and cell processing. The objective of silicon microphotonics is to establish an IC compatible process technology for integration of optical interconnection with silicon electronics. By building the first silicon-based LED operating at λ = 1.54 μm at room temperature it has been shown that erbium doping is a viable approach. Codoping with F or O largely enhances the light output. We will show a process simulator for the Si:Er:F system as an example for ligand field engineering.
Electrical and Structural Properties of MeV Si+ Ion Implantation in Silicon
Authors: Agarwal Aditya , Koveshnikov S. , Christensen K. , Rozgonyi G. A. 
Published: April 2011

AbstractThe electrical properties of residual MeV ion implantation damage in Si after annealing from 600 to 1100°C for 1 hour have been investigated using Deep Level Transient Spectroscopy, Capaciatance-Voltage, and Current-Voltage measurements. These data have been correlated with structural defects imaged by Transmission Electron Microscopy. It is shown that at least 4 deep levels are associated with the buried layer of extended defects after annealing at 800, 900, 1000 and 1100°C. Additionally, for the wafer annealed at 800°C at least 5 more deep level centers are present in the device layer above the buried defects.
Effects of Light on the Resonant Tunneling in Silicon Quantum Dot Diode
Authors: Ding Chen , Tsu Raphael 
Published: April 2011

AbstractThe resonant tunneling via nanoscale silicon particles embedded in an a-SiO2 matrix in a diode structure has revealed a range of intriguing observations such as extremely sharp peaks and steps and periodic oscillations in (conductance-voltage) G-V measurements. Recently we have discovered a drastic sharpening of the conductance peak with light. Phase measurements show that the effects of light may be understood by invoking the filling of charged traps.
Space Charge Layers at the Porous Silicon Surface
Authors: Weisz S. Z. , Avalos J. , Gomez M. , Many A. , Goldstein Y. , Savir E. 
Published: April 2011

AbstractPulse measurements on the porous-Si/electrolyte system are employed to determine the surface effective area and the surface-state density at various stages of the anodization process used to produce the porous material. Such measurements were combined with studies of the luminescence spectra and scanning tunneling microscopy (STM). Both the effective area and the luminescence intensity are found to increase with anodization time, reaching maximum values for the same anodization time (1–2 minutes). In most cases, they decrease monotonically with further anodization. The surface state density, on the other hand, decreases with anodization time from the initial value of ∼1012 cm−2 for the virgin surface, down to ∼1011 cm−2 at the common anodization time for which both the effective area and the luminescence intensity are peaked. The surface-state density increases upon further anodization, reaching a value of at least 1013 cm−2 after ∼10 minutes of anodization. Apart from its intensity, the luminescence spectrum is essentially independent of anodization time. The common peak of the spectra is at about 700 nm. The STM measurements reveal a pronounced surface roughness. Preliminary results indicate that for 1 - 2 minute anodization (maximum effective area), the roughness scale is of the order of 1 -2 nm. After 10-minutes anodization, on the other hand, the roughness microstructure becomes finer (roughness scale of only 0.5 - 0.7 nm). These findings indicate that the various characteristics studied are closely interrelated. Such information may help in understanding the luminescence mechanism, but further work is required in order to interpret more fully the results presented.
Nanotesla Detection Using the Planar Hall Effect
Authors: Schuhl A. , Van Dau F. Nguyen , Childress J.R. 
Published: April 2011

ABSTRACTA magnetic field sensor based on the planar Hall effect has been developed using epitaxial permalloy (Ni80Fe20) ultrathin films (1-10 nm). The magnetic and magnetotransport properties of these films have been studied in detail. For thicknesses above 5 nm, the resistivity of the permalloy film is below 5μΩ-cm, and its magnetoresistance ratio is 2%. By using the transverse resistivity for detection, we have reduced thermal drift effects by five orders of magnitude. We also make use of a weak uniaxial anisotropy induced in the permalloy through exchange coupling with a 6 nm-thick Fe/Pd multilayer, itself grown directly on the MgO substrate. Magnetic sensors based on these films have been used successfully to detect fields below 10 nT at 1Hz. Since the lateral dimensions of the sensing element are small (<30μm), and because of the ferromagnetic coupling with the Fe/Pd structure, it consists of a single magnetic domain. Sensitivities above 100 V/T-A have been obtained, with deviations from linearity of less than 2% over 4 decades.
Structural Coherence and Magnetic Coupling in Fe/Si
Authors: Foiles C.L. , Franklin M.R. , Loloee R. 
Published: April 2011

ABSTRACTA number of studies have inferred the presence of an Fe-silicide in Fe/Si multilayers. Our transmission electron diffraction data provide direct evidence for the presence of an Fe-silicide. Despite similarities in structural coherence and saturation magnetization behavior for Fe/Si and Fe/{FeSi}, direct evidence for Fe-silicide only occurs for the Fe/{FeSi} multilayers.
Process-Induced Uniaxial Magnetic Anisotropy in Epitaxial Fe and Ni80Fe20 Films
Authors: Childress J.R. , Durand O. , Nguyen Van F. , Galtier P. , Bisaro R. , Schuhl A. 
Published: April 2011

ABSTRACTThe occurrence of a weak in-plane uniaxial magnetic anisotropy in Fe thin films grown by molecular beam epitaxy onto (001)-oriented MgO substrates has been previously reported. We explain the occurrence of this anisotropy by measuring the in-plane tetragonal distortion of the cubic Fe lattice in a 800Å-thick film. The analysis of the full x-ray diffraction spectrum reveals a 0.1% difference between the two in-plane parameters. This small difference is sufficient to fully explain the observed anisotropy (≈20 Oe) using a standard magnetoelastic model. Although it is established that the uniaxial anisotropy results from the angle of incidence of the Fe atomic flux during deposition, the relationship between angle of incidence and in-plane tetragonalization is still unexplained. However, this anisotropy is shown to also occur in other epitaxial systems such as Ni80Fe20 on (111)Si. Control of this effect can help design epitaxial multilayer films with specific and reproducible magnetic states.
Magnetic Structures in Nonmag-/MAG-/Nonmag-Netic Sandwiches
Authors: Kawazoe Yoshiyuki , Hu Xiao 
Published: April 2011

ABSTRACTSpin-reorientation transition in magnetic thin film sandwiched by nonmagnetic materials is clarified by means of the variational formalism. Phase diagrams of the magnetization configuration are presented. Scaling relations among the film thickness, exchange coupling and magnetic anisotropies are revealed. A formula for the interface anisotropy is presented.
Induced Magnetic Anisotropy of Sputter NiFe Thin Films on Thin Tantalum Nitride Underlayer
Authors: Yeh T. , Berg L. , Falenschek J. , Yue J. 
Published: April 2011

ABSTRACTThe structure and properties of sputter NiFe thin film deposited on both thermal oxide and thin tantalum nitride have been studied. The magnetic anisotropy field HK increases to 8.2 Oe when the NiFe film was deposited on a thin tantalum nitride underlayer. Anisotropic stress was found on the sample film with tantalum nitride underlayer. Results of X-ray diffraction show that a thin tantalum nitride underlayer appears to promote a preferred crystalline orientation formation of the NiFe film. The induced magnetic anisotropy is attributed to the formation of the preferred crystalline orientation and the induced anisotropic magnetoelastic energy which is associated with the anisotropic stress of the sample film.
Structural and Magnetic Characterization of Bi-Substituted Garnet on Si and GaAs
Authors: Ring Ken M. , Shapiro A.L. , Deng F. , Goldman R.S. , Spada F. , Hellman F. , Cheeks T.L. , Kavanagh K.L. , Suzuki Takao 
Published: April 2011

ABSTRACTNovel material structures that combine magneto-optic (MO) and semiconductor devices have potential applications in monolithic microwave systems and optoelectronics. We have investigated the materials issues pertaining to the film structure, interface uniformity, and magnetic/MO properties of (BiDy)3(FeGa)5O12 (Bi-DyIG) thin films sputter deposited on Si and GaAs. The rapid thermally annealed films were polycrystalline with a nominal grain size of 20 nm. The magnetic and MO properties were strongly dependent on the type of substrate such that square hysteresis loops and coercivities of 0.1 to 0.9 kOe were observed for Bi-DyIG/Si structures while Bi-DyIG/GaAs structures showed much lower coercivity values (0.03 kOe). A comparison of the magnetic properties, microstructure and substrate composition was carried out with plan-view and cross-section transmission electron microscopy, as well as electron and x-ray diffraction. The results suggest that grain orientation effects, stress, and compositional inhomogeneity due to interfacial reactions or diffusion introduced by the substrate strongly influence the magnetic and MO properties of the films.
Selective one-step Chemical Etching of the Silicon Nitride/Silicon PBL stack for 0.5μm device Fabrication
Authors: Ziger David , Vitkavage Susan , Oberdorfer Charles , Eisenberg Juli , Hughes Michael 
Published: April 2011

ABSTRACTAbstract Wet chemical removal of a silicon nitride/silicon Poly Buffer LOCUS (PBL) film stack with a phosphoric/nitric acid solution was characterized. Though silicon nitride etch rates remain constant, silicon etch rates decrease as a function of loading which severely limits the usable lifetime of the bath. This is caused by buildup of etching products which limits the amount of silicon that can be dissolved in the solution. Addition of HF to the phosphoric/nitric acid solution enhances the dissolution chemistry presumably by decomposing the silica reaction products and shifting the equilibrium. Characterization of this process was done to determine whether it could be applied towards PBL removal. Depending on the relative amounts of HF and HNO3 added, silicon etch rates could be enhanced by two orders of magnitude (200–400A/min) and silicon nitride etch rates by a factor of two. Selectivities for etching silicon to oxide and silicon nitride to oxide were typically between 8–12:1 and 8–20:1 respectively.
Monitoring of the Surface Species on Silicon After Chemical Cleaning by FTIR Spectroscopy
Authors: Chung Chan-Hwa , Kim Chang-Koo , Moon Sang Heup 
Published: April 2011

ABSTRACTFor the analysis of as-cleaned surface, we have used a the unique IR method that uses a highsurface-area porous sample. We have observed by experiments that the oxide growth rate on silicon is reduced to a minimum when the surface is treated with a proper amount of HF vapor obtained from 1% I-IF solution. FTIR and XPS observations of the treated surface suggest that the oxide growth rate is closely related to the amount of the surface fluorides. In UV/O2 cleaning process, we have observed experimentally that addition of water vapor to cleaning gas stream enhances the cleaning efficiency by as much as 1.3 times.
Pre-Gate Oxidation Cleaning of Silicon Wafer by Electric Arc Plasma Jet Treatment
Authors: Pavlov G. Ya. 
Published: April 2011

ABSTRACTThe effect of arc plasma jet treatment (APJT) of silicon surface used for pre-gate oxidation cleaning on the electrophysical parameters of MOS structures (Si/SiO2/Si*/Al) has been studied- We show that APJT etching cleaning considerably improves the constant current charge to breakdown of MOS structures in comparison with conventional wet chemical cleaning. We have analyzed the effect of plasma cleaning conditions on the quality of gate oxide and SiO2/Si interface.
Ion-Beam-Induced Epitaxy and Solid Phase Epitaxy of Sigec on Si Formed by Ge and C Ion Implantation and their Structural and Optical Properties
Authors: Kobayashi N. , Katsumata H. , Makita Y. , Hasegawa M. , Hayashi N. , Shibata H. , Uekusa S. , Hishita S. 
Published: April 2011

AbstractEpitaxial layers of Si1-x-yGexCy on Si(100) (x=0.13 and y=0.014 at peak concentration) were formed by ion implantation of Ge ions and C ions at room temperature (RT) and by subsequent IBIEC (ion-beam-induced epitaxial crystallization) process with 400keV Ge and ar ions at 300-400°C and SPEG (solid phase epitaxial growth) process up to 840°C. Crystallization up to the surface both by IBIEC and SPEG processes has been confirmed with RBS-channeling analysis. X-ray diffraction experiments have demonstrated strain compensation by incorporation of C atoms for IBIEC-grown Si1-x-yGexCy/Si samples, whereas strain accommodation due to C precipitation has been observed for SPEG-grown Si1-x-yGexCy/Si samples. Photoluminescence (PL) observed at 2K from IBIEC-grown samples has shown intense I1 peak with/without I1 related (Ar) peak and that from SPEG-grown samples has shown G line emission. these optical properties could suggest that small vacancy agglomeration is dominant in IBIEC-grown samples and C agglomeration is dominant in SPEG-grown samples, respectively.
Film Synthesis on Powders by Cathodic ARC Plasma Deposition
Authors: Anders André , Anders Simone , Brown Ian G. , Ivanov Igor C. 
Published: April 2011

AbstractCathodic arc plasma deposition was used to coat Al2O3 powder (mesh size 60) with platinum. the power particles were moved during deposition using a mechanical system operating at a resonance frequency of 20 Hz. Scanning electron microscopy and auger electron microscopy show that all particles are completely coated with a platinum film having a thickness of about 100 nm. the actual deposition time was only 20 s, thus the deposition rate was very high (5 nm/s).
Corrosion Protection of Aluminum-Matrix Composites
Authors: Hou Jiangyuan , Chung D. D. L. 
Published: April 2011

ABSTRACTAluminum-matrix composites are attractive in their combination of low CTE and high thermal conductivity. Anodizing is an effective surface treatment for improving the corrosion resistance of aluminum-matrix composites. ForSiC filled aluminum, anodizing was performed successfully in an acid electrolyte, as usual. However, for AIN filled aluminum, anodizing needed to be performed in an alkaline (NaOH) electrolyte instead of an acid electrolyte, because NaOH reduced the reaction between AIN and water, whereas an acid enhanced this reaction. The concentration of NaOH in the electrolyte was critical; too high a concentration of NaOH caused the dissolution of the anodizing product (A12O3) by the NaOH, whereas too low a concentration of NaOH did not provide enough ions for the electrochemical process.
Nickel Filament Polymer-Matrix Composites with Low Surface Impedance and High Electromagnetic Interference Shielding Effectiveness
Authors: Shui Xiaoping , Chung D. D. L. 
Published: April 2011

ABSTRACTNickel filaments of 0.4 μm diameter gave polyethersulfone-matrix composites with high electromagnetic interference shielding effectiveness and low surface impedance at 1–2 GHz. With 7 vol.% nickel filaments, the composite exhibited shielding effectiveness 87 dB (compared to 90 dB for solid copper), surface impedance 1.2 Ω (same as for solid copper), tensile strength 52 MPa, modulus 5 GPa, ductility 1.0% and density 1.87 g/cm3. The low surface impedance is valuable for microwave waveguides.
Excimer Laser Direct Write Aluminum on Aluminum Nitride
Authors: Li Hua , Lumpp Janet K. 
Published: April 2011

ABSTRACTFabrication of metal lines on aluminum nitride (AIN) ceramic is important for application of AIN as a microcircuit board. An Al line can be made directly from AIN by excimer laser exposure. All lines in this paper were written by pulsed KrF excimer laser (248 nm) in air and vacuum at different scan speeds with a constant laser energy. The morphology of the Al lines was observed by optical and scanning electron microscopies. The lines become more metallic when the scan speed decreases. Consequently the resistance, measured by the four-point probe technique, decreased to a minimum value in the scan speed range of 400 μm/s to 900 μm/s for the samples made in air. The resistance of Al lines written in air is greater than that in vacuum because of oxidation. The samples made in air with scan speed lower than 400 μm/s were heavily oxidized. SAXPS spectra showed a strong oxidation state and that the excimer laser exposure depletes nitrogen from AMN. The Al lines produced by laser-induced decomposition of AMN board are being evaluated as catalysts for laser assisted CVD and conventional electroless plating. The oxidation layer on the surface of Al lines may effect the adhesion between the Al lines and the deposited or plated metal.
Adhesion Strength of CuCr Alloy Films to Polyimide
Authors: Ahn E. C. , Yu Jin , Park I. S. 
Published: April 2011

ABSTRACTIn the present work, CuCr alloys with varying Cr content were sputter deposited on polyimide films, and the metal/polyimide thin films were maintained under 85° C/85%R.H. (T/H) conditions for the reliability measurements. Results showed that the peel strength without T/H treatments increased proportionally with the Cr content in the CuCr alloy layer(x) up to 17 at. %, and then saturated. Among the samples studied, the peel strength decreased with hold time under T/H conditions for all the cases, but most drastically for the sample with x=8.5. The very poor peel strength of that sample (x=8.5) was attributed to the occurrence of interfacial failures which were thought to take place along Cr-oxide/polyimide interfaces.
Sol-Gel Derived Polyvinylpyrrolidone/Silicon Oxide Composite Materials and Novel Fabrication Technique for Channel Waveguide
Authors: Yoshida Makoto , Prasad Paras N. 
Published: April 2011

AbstractSol-gel derived composite materials of polyvinylpyrrolidone (PVP), SiO2 and TiO2 were studied to achieve low optical propagation loss and high thermal stability in slab waveguides. PVP is a thermally crosslinkable polymer. However, the thermal crosslinking and thermal decomposition take place around the same temperature, 200 °C, resulting in high optical propagation loss. The incorporation of sol-gel processed SiO2 prevents thermal decomposition of PVP and produces remarkably low optical propagation loss even after being baked at 230 °C. We have achieved 0.2 dB/cm optical propagation loss at 633 nm. Furthermore, little index change was observed at 110 °C for 1,000 hours after initial slight increase. Impregnation of sol-gel processed TiO2 into the PVP/SiO2 system was also studied to increase refractive index. A broad manipulation of refractive index, from 1.49 to 1.65, with an optical propagation loss of less than 0.6 dB/cm at 633 nm was accomplished by a careful selection of Ti alkoxide and optimized reaction conditions. PVP/SiO2 slab waveguides were then used to fabricate channel waveguides by using a laser densification technique utilizing metal lines as light absorbent and an Ar laser. An optical propagation loss of 0.9 dB/cm was achieved at 633 nm.
Non-Radiative Competition in the Excitation of Erbium Implanted Silicon Light Emitting Devices
Authors: Taskin T , Huda Q , Scholes A , Evans J H , Peaker A R , Hemment P , Jeynes C , Jafri Z 
Published: April 2011

AbstractThis paper reports a study of the non-radiative processes competing with the excitation of the erbium ion in layers implanted with high concentrations of erbium and oxygen. These processes reduce the luminescence efficiency of the Si:Er system and dramatically increase the threshold current density calculated to be necessary for an ultimate goal, the Si/Ge:Er LASER. Using cross sectional TEM, photoluminescence as a function of temperature and DLTS, it is demonstrated that a two stage anneal procedure which avoids the formation of extended defects and removes specific deep states is necessary to obtain efficient Er3+ excitation at high erbium concentrations. Comparisons are made with damage resulting from germanium implantation into silicon. The role of multiple stage anneals is discussed in relation to the removal of Shockley-Hall-Read recombination centres
Polymeric Thin Films for Electro-Optic Modulator and High Density Optical Memory Applications
Authors: Dalton Larry R. , Harper Aaron W. , Liang Zhiyong , Zhu Jingsong , Efron Uzi , Wu Chiung-Shieng , Au Anson 
Published: April 2011

AbstractChromophores capable of undergoing conformational changes when exposed to ultraviolet or visible light have been synthesized with functional groups permitting attachment to polymer matrices. One class of such chromophores, containing reactive functionalities at both ends of the chromophore, are referred to as double-end crosslinkable (DEC) chromophores. These chromophores are used in the synthesis of hardened nonlinear optically active lattices and in the fabrication of buried channel nonlinear optical waveguides by photoprocessing; development of such waveguides represents a critical step in the production of polymeric electro-optic modulators. Such chromophores are also crucial to the phenomena of laser-assisted poling (also known as photochemically-induced poling). Finally, these chromophores are attached to the surface of polystyrene beads permitting the realization of room temperature spectral hole burning exploiting morphology-dependent resonances. Such resonances provide the basis of wavelength coding for the development of high density optical memories.