bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Ion Irradiation on the Microstructure of Fe/Ti Multilayers
Authors: Kopcewicz M. , Grabias A. , Jagielski J. , Stobiecki T. 
Published: April 2011

ABSTRACTThe amorphization of the Fe/Ti multilayers due to ion-beam mixing induced by Ar and Kr ions is studied by conversion electron Mossbauer spectroscopy. Formation of the bcc-FeTi solid solution and the amorphous FeTi phase is studied as a function of ion dose for samples with the Fe to Ti thickness ratio of 1 and the modulation wavelengths of 20 and 60 nm. After reaching maximum abundance the amorphous fraction decreases at high ion doses.
Electron Paramagnetic Resonance Study of Ion-Implanted Photorefractive Crystals
Authors: Darwish A. , Ila D. , Willams E. K. , Poker D. B. , Hensley D. K. 
Published: April 2011

ABSTRACTThe effect of the ion implantation (Fe) on LiNbO3, MgO, and A12O3 crystals is studied using electron paramagnetic resonance (EPR). EPR measurements on these crystals were performed as a function of fluence at room temperature. The fluence was 1 × 1014 and 1 × 1016 ions/cm2. The unpaired carrier concentration increases with increasing fluence. The photosensitivity of these crystals was determined by observing in situ the effect of the laser illumination on the EPR signal and measuring the decay and the growth of the EPR signal. The EPR signal of Fe3+ was found to decrease in both MgO, and Al2O3; and was found to increase in LiNbO3. This indicated that in case of MgO, and A12O3 Fe3+ will transfer into Fe2+/Fe4+, but in case of LiNbO3 Fe2+/ Fe4+ will transfer into Fe3+; increasing the EPR signal. This was found primary due to some Fe2+ and Fe4+ ions, which is not intentionally doped on the LiNbO3 crystal but exist as a defect on the crystal.
Formation of Nanocluster Colloids of Tin, Gold and Copper in Magnesium Oxide by MeV Ion Implantation
Authors: Zimmerman R. L. , Ila D. , Williams E. K. , Sarkisov S. , Poker D. B. , Hensley D. K. 
Published: April 2011

ABSTRACTWe have implanted ions of Sn, Au and Cu at energies between 160 keV and 2.0 MeV into single crystals of MgO (100) at room temperature. The formation of nanoclusters was confirmed using photospectrometry, in combination with Mie's theory, which was indirect but nondestructive. Using Doyle's theory, as well as Rutherford Backscattering Spectrometry (RBS), we correlated the full width half maximum of the absorption bands to the estimated size of the metallic nanoclusters between 1–10 nm. These clusters were formed both by over implantation and by a combination of threshold fluence of the implanted species and post thermal annealing. The changes in the estimated size of the nanoclusters, after annealing at temperatures ranging from 500°C to 1000°C, were observed using photospectrometry.
Enhancement of Adhesion Between Cu Thin Film and Polyimide Modified by Ion Assisted Reaction
Authors: Choi S. C. , Kim K. H. , Jung H-J. , Whang C. N. , Koha S. K. 
Published: April 2011

ABSTRACTPolyimide films are modified by ion assisted reaction method using various ion beams in various gases environments. Amount of ion and blown gases rate were changed from 5 × 1014 to 1 × 1017 and from 0 to 8 sccm, respectively. Wetting angles between water and polyimide films modified by Ar+ ion without oxygen blowing decrease from 67° to 400° and surface free energies increase from 46 to 64 dyne/cm2. Wetting angle of polyimide films modified by Ar+ ion in an oxygen environment decreases to 12° and surface free energy increases to 72 dyne/cm2. The lowest wetting angle was obtained by oxygen ion irradiation in the oxygen gas environment and its value was 7°. In the case of polyimide film modified by Ar+ ions in an oxygen environment, the wetting angle increases up to 65° when it kept in air and that increases up to 46° when it kept in water after 5 day. In the case of polyimide film modified by O2+ ion in oxygen environment, however, the wetting angle of polyimide film dose not increase. X-ray photoelectron analysis shows that the chemical bonds between polyimide components are severed by ion irradiation and hydrophilic groups such as CO and C=O are formed by the reaction between newly formed radicals and blown oxygen. It was found that adhesion between Cu and polyimide modified by ion assisted reaction was improved. The main reason of the enhanced adhesion is due to the reaction between Cu and C-O or C=O groups formed by ion assisted reaction on the polyimide surface.
Argon-surface interactions in ibad-deposited molybdenum films
Authors: van der Kuur Jan , Korevaar Bas , Pols Martin , van der Linden Jacqueline , Thijsse Barend 
Published: April 2011

ABSTRACTArgon incorporation and defect creation were studied experimentally. Direct desorption measurements have been used to establish the argon implantation profile. A projected range and range straggle of 0.8 and 3.5 Å were found. Argon is incorporated at substitutional positions. The creation rate of defects by argon was studied by helium desorption spectrometry. A net creation rate of (0.7 ± 0.4) × 10−3 vacancy/argon atom was found. Ion assisted deposition at elevated substrate temperatures shows that all incorporated argon acts as helium trap. Argon fluence variations show an effective cross-section for self sputtering of 31 Å2, a trapping probability of 6.5%, and a maximum achievable argon concentration of 4 × 10−3
Ion Yield, Sputter Rate, and Sims Matrix Effects in Quantitative Analysis of (AlxGa1−x)0.5N0.5
Authors: Lefforge D.L. , Chang Y.L. , Ludowise M. , Allen E.L. 
Published: April 2011

AbstractAluminum gallium nitride (AlGaN) material is used in GaN-based electronic and optoelectonic devices. The Al and Ga ratio can be adjusted to produce material with different compositions and electronic properties. In this set of experiments epitaxial films of (AlxGa1−x)0.5N0.5 with x ranging from 0 to 1 were investigated. Primary composition was determined with Rutherford backscattering spectrometry (RBS). From secondary ion mass spectrometry (SIMS) profiles a correlation of secondary ion counts was made to RBS determinations of primary composition. The SIMS data was also used to determine sputter rate and the relative sensitivity factor (RSF) of O, Mg and Si in (AlxGa1−x)0.5N0.5 material. The correlation of SIMS data with RBS and knowledge of the sputter rate and RSF dependence on composition are essential for the characterization of (AlxGa1−x)0.5N0.5 films
Intrinsic Gettering of Nickel and Copper for Advanced Low Temperature Device Processes
Authors: Ogushi S. , Reilly N. , Sadamitsu S. , Koike Y. , Sano M. 
Published: April 2011

AbstractThe formation and dissolution of Ni and Cu silicides were investigated to determine effective intrinsic gettering (IG) for low temperature processes. Ni formed silicides easily at low contamination levels and these silicides formed the nuclei for OSF during subsequent annealing at temperatures above 1000°C. Ni silicides were dissolved and gettered during low temperature deposition of a poly-back seal (PBS) at 620°C, whereas Cu silicides, once formed, easily induced secondary defects on further annealing even at low temperatures and could not be dissolved or gettered by PBS. The sizes and densities of oxygen precipitates necessary to intrinsically getter Ni and Cu contamination levels of 1012atoms/cm2 were also investigated with respect to generation lifetime. Cu contamination at this level did not degrade generation lifetime or gate oxide integrity (GOI) yield. For Ni contaminated samples, a strong dependence of generation lifetime on both oxygen precipitate density and size was observed. Effective IG for Ni during a low temperature process was demonstrated using a 2-step low temperature process simulation.
Near Surface Defect Distribution in Silicon Under Etching
Authors: Yarykin Nikolai A. 
Published: April 2011

AbstractThe distribution of hydrogen penetrated into n-type silicon crystals during chemical etching is described mathematically. The depth profiles of the defects passivated by hydrogen and of defect-hydrogen complexes are also calculated. Comparison with the experimental data obtained on the silicon crystals with radiation defects and doped with transition metals reveals that the model adequately describes the processes in the crystal. By comparing the parameters of the depth profiles, the passivation and appearance of different defects are shown to be caused by the same diffusing species. The number of hydrogen atoms contained in the defect-hydrogen complexes and the distance of the hydrogen-defect interaction are determined from the characteristic length of the defect distribution. The diffusion length (1 to 3 νm) and diffusivity (> 5-10−9 cm2s−1) of hydrogen at room temperature are found indirectly based on the other defect distribution.
Ion Implantation-Induced Defects and the Influence of Titanium Silicidation
Authors: Chi D.Z. , Ashok S. , Theodore D. 
Published: April 2011

AbstractThermal evolution of ion implantation-induced defects and the influence of concurrent titanium silicidation in pre-amorphized p-type Si (implanted with 25 KeV, 1016 cm2Si+) under rapid thermal processing (RTP) have been investigated. Presence of implantation-induced electrically active defects has been confirmed by current-voltage (IV) and deep level transient spectroscopy (DLTS) measurements. DLTS characterization results show that the evolution of electrically active defects in the Si implanted samples under RTP depend critically on the RTP temperature: Hole traps HI (0.33 eV) and H4 (0.47 eV) appear after the highest temperature (950 °C) anneal, while a single trap H3 (0.26 eV) shows up at lower anneal temperatures (≤ 900 °C). The thermal signature of H4 defect is very similar to that of the iron interstitial while those of HI and H3 levels appear to originate from some interstitial-related defects, possibly complexes. A most interesting finding is that the above interstitial related defects can be eliminated completely with Ti silicidation, apparently a result of vacancy injection. However the silicidation process itself introduces a new H2 (0.30 eV) level, albeit at much lower concentration. This same H2 level is also seen in unimplanted samples under RTP. The paper will present details of defect evolution under various conditions of RTP for samples with and without the self-implantation and silicidation.
Structural and Photoluminescence Studies of Er Implanted Lt-GaAs:Be
Authors: Maltez R.L. , Liliental-Weber Z. , Washburn J. , Behar M. , Klein P.B. , Specht P. , Weber E.R. 
Published: April 2011

AbstractCharacteristic 1.54 μm Era3+ emission has been observed from Er-implanted and annealed, low-temperature grown GaAs:Be samples. Cross-sectional transmission electron microscopy (TEM) studies reveal very little structural damage for elevated temperature implants up to an Er total fluence of 1.36 × 1014 Er/cm2. No Er emission was observed from any of the as-implanted samples, while post-implantation annealing optimized the Er emission intensity near 650°C. The Er-emission appears on top of a broad background luminescence peaking near 1500 nm. Significant enhancement of the optically active Er incorporation was achieved when the implantation was carried out at 300TC. The Er emission intensity was found to scale linearly with the Er implantation fluence for samples with an Er concentration up to ∼1019 Er/cm3. The sample with the highest Er concentration (∼1020 Er/cm3) began to show a sublinear dependence. The beginning of Er precipitation was observed after 750°C annealing, but it could even be observed after a 650°C annealing for the highest Er concentration sample. These precipitates are likely ErAs.
Boron Clusters in a Complex Defect in Silicon
Authors: Okamoto M. , Takayanagi K. , Takeda S. 
Published: April 2011

AbstractWe have investigated stability of a new kind of boron clusters in silicon crystal using the first-principles local density functional approach. In the calculation, we used three types of hydrogenterminated silicon clusters; one of these types included the four interstitial cluster I4 as a complex defect. According to our calculation, we found that a new kind of boron clustering of n-borons substituted I4 (n < 3) became most stable when the ratio r = N(Bi) / (N(Sii) + N(Bi) in a confined area was less than or equal to 1/2, where N(B) is a number of interstitial boron atoms and N(Sii) is that of interstitial silicon atoms. On the other hand, when r was greater than 1/2, the l4 would be destroyed to create the [100] split boron pair, the [110] split silicon pair, and/or the substitutional boron and interstitial silicon pair.
Point Defect Characterization of Zn- and Cd-Based Semiconductors Using Positron Annihilation Techniques
Authors: Tessaro G. , Mascher P. 
Published: April 2011

AbstractA study of point defects in II-VI compound semiconductors was undertaken and has revealed that open volume defects are present in a wide variety of these samples. Zn-based binary compounds contain primarily neutral divacancy defects in concentrations in the mid 1016 cm−3. CdTe samples contain neutral monovacancy sized defect complexes in the high 1016 cm−3 range. When a small fraction of Zn or Se is alloyed into CdTe the defect profile changes dramatically to one dominated by divacancy sized defects at roughly half the original concentration.
A Novel Detection System for Defects and Chemical Contamination in Semiconductors Based Upon the Scanning Kelvin Probe
Authors: Lägel Bert , Baikie Iain D. , Petermann Uwe 
Published: April 2011

AbstractA novel wafer scale detection system for defects and chemical contamination in semiconductors based upon the Scanning Kelvin Probe (SKP) is presented. It incorporates traditional work function (wf) topography with high resolution (<0.1 meV), Surface Photovoltage (SPV) measurement and the acquisition of SPV transients with time constants down to I ts. This permits quasi-simultaneous determination of surface charge, surface barrier height and bulk minority carrier lifetime. Monitoring variations of these parameters after chemical treatments give an accurate indication of the location and amount of contamination.The SKP system is introduced and the SPV and SPV transient measurement modes are discussed. Measurements on Fe-contaminated and Au-implanted Si wafers demonstrate the feasibility of the system for defect and impurity characterisation in semiconductors. The system is both non-contact and non-destructive, requires no wafer preparation and can be applied in both ambient and vacuum environments.
On the Mechanical Properties of a Poly(oxazolidone) Polymer for Encapsulant Applications
Authors: Manoharan M. , Chian K. S. 
Published: April 2011

ABSTRACTEpoxy based resins have been widely used as encapsulation materials in microelectronics components due to their good mechanical, thermal and electrical properties, outstanding adhesion to various substrates and the ability to be processed under a variety of conditions. These epoxy resins have a high glass transition temperature but low toughness and damage tolerance. As electronic devices continue to be miniaturized and the scale of integration increases, the encapsulation of these chips leads to mechanical and thermal stress related failures. Mechanical stresses could result from the mismatch in thermal expansion rates between the polymeric encapsulant, the silicon chip and the metal leadframe. The accommodation of these stresses may lead to cracking of the encapsulant or delamination. In this study, poly(oxazolidone) polymer was prepared by reacting 4,4′-Diphenyl-methanediisocyanate (MDI) with diglycidyl ether of bisphenol A (DGEBA) at elevated temperature. The mechanical properties of this polymer were investigated both as a stand-alone material as well as a bi-material sandwich with a brittle substrate. The degree of cracking in the substrate is shown to be a function of the thickness of the polymer layer. This result is analyzed based on the variation in the position of the neutral axis in this composite.
Thermal Control of Interfaces for Microelectronic Packaging
Authors: Marotta E. E. , Hana B. 
Published: April 2011

ABSTRACTThe continuous miniaturization of electronic devices places an ever-increasing importance on the thermal management of electronic systems and its subcomponents. The increased power densities and heat generation, due to the miniaturization of the device line features, may lead to higher operating temperatures and greater warpage between the silicon device and its organic carrier. The higher operating temperature may result from the degradation of the overall thermal performance. These additive effects will also lead to an increasing number of thermally induced failures, which will be further magnified when future microelectronic packaging incorporates flip-chip technology.The higher operating temperatures within microelectronic systems result from inadequate dissipation of the heat generated, while the warpage effect is caused by the mismatch between the thermal coefficients of expansion (ICE) induced by thermal stresses. Often these high temperatures result from the thermal resistance between subcomponents, such as between the contacting surfaces of laminated printed circuit boards, device/epoxy cement and heat spreader (i.e., finned heat sink or heat pipe), and any other metallic or non-metallic interstitial material employed between contacting interfaces.Published experimental data of potential coatings, adhesives, and elastomeric gaskets is presented that can improve the thermal contact conductance of contacting surfaces within microelectronic systems. In addition, recommendations for future analytical and experimental studies of the mnechanistic principles, which control thermal performance of interstitial materials, are discussed for non-uniform pressure distribution.
The Effects of Interfaces on C-4 Solder Bump Reliability
Authors: Sullivan Michael J. 
Published: April 2011

ABSTRACTC-4 solder bump technology is used as an interconnect method between microelectronic chips and substrates because of four unique features; excellent electrical performance, large number of connections in area arrays, small size and superb reliability in properly fabricated terminals. C-4 terminals consist of chip metallization (BLM or UBM), solder, substrate metallization and underfill, if needed. The reliability of C-4 interconnections will be described in terms of the physical interfaces in the terminal which include insulator-metal, metal-intermetallic, grain boundary and, if needed, underfill-chip/substrate/solder interfaces. Some of these interfaces are present in the as-deposited materials while others form during the solder reflow operation. Reactive UBM's such as Ti/Cu/Au form layers of intermetallic compounds such as TiCu, TiCu2 and TiCu3 and react with hydrogen ambients to form TiH2. The solder reacts with the UBM copper to form Cu3Sn and Cu6Sn5. The solder also reacts with the substrate metallization (electroless Ni-Au as an example) to form Ni3Sn2 and Ni3Sn4. Reactions with Au also occur with the formation of TiAu4 and AuSn. These reactions can cause problems not because the intermetallics are brittle (intermetallics are relatively brittle compared to the solder but they are also very strong as compared to the solder), but because of the consequences of the reactions such as, stress increase, impurity snowplow, Kirkendall voids and intermetallic spalling. Non-reactive UBM's like Cr/Cu/Au require a “phased” region between the Cr and Cu to achieve mechanical adhesion because of the absence of reaction. Proper control of these reactions will eliminate early fails that are usually planar and occur at reaction interfaces. Long term wear-out will occur during power on-off cycling when creep/fatigue cracks nucleate and grow at the grain boundaries in the solder. If underfill is used, impurity assisted crack growth at underfill to chip/substrate/solder interfaces results in increased strain on the solder and failure. Reliability models for these various failure mechanisms will be discussed as well as methods of eliminating early interfacial failures.
The Effects of Substrate Preheating and Post-Deposition Annealing on CrMn/CoCrPt/CrMn/NiAI Films
Authors: Zou Jie , Laughlin David E. , Lambeth David N. 
Published: April 2011

AbstractIn this study, we examine the effects of introducing CrMn as an intermediate layer between the NiAI underlayer and the CoCrPt magnetic layer, and as an overlayer on top of the Co-alloy film. The effects of deposition temperature and post-deposition annealing on the texture and magnetic properties were studied. Post-deposition annealing effectively lowered the exchange coupling between grains, increased the coercivity by 38%, up to 4600 Oe, and moderately decreased the Ms by 15%. Interlayer diffusion of CrMn into the CoCrPt grain boundaries is believed to cause the change in magnetic properties. It was also found that granular exchange coupling seems to be correlated to the Co-alloy in-plane texture.
A Lens-Free and Mirror-Free Fiber Integrated Optical Magnetic Field Sensor Using Bi-Substituted Garnet
Authors: Minemoto H. , Itoh N. , Ishiko D. , Ishizuka S. 
Published: April 2011

AbstractWe have developed a novel lens-free and mirror-free fiber integrated optical magnetic field sensor. The use of a bent optical fiber and chip optical components allows easy assembly with no alignment. The linearity error and temperature dependence of the sensitivity of this sensor were less than ±1% and +2%, respectively.
Solution Flow System for Hydrothermal-Electrochemical Synthesis: New Opportunities for Multilayered Oxide Films
Authors: Suchanek W. , Watanabe T. , Sakurai B. , Yoshimura M. 
Published: April 2011

AbstractA solution flow system for hydrothermal-electrochemical synthesis has been constructed in our laboratory. This equipment can operate at 20°-200°C, under the pressure of 1-50 atm., at flow rate of 1-50 cm3/min. Applicability of the flow system for low-temperature, hydrothermalelectrochemical synthesis of single-layer and multilayered thin films has been demonstrated using the BaTiO3-SrTiO3 system as an example. Single phase thin films as well as double layers have been deposited at 150°C, current density of 1 mA/cm2, and flow rates of 1-50 cm3/min. The flow rate is an important parameter allowing additional control of the films' morphology by affecting the growth rate. The multilayers can be prepared in only one experiment by simply changing the flowing solution. Processing using the solution flow cell may serve as an inexpensive and environmentally friendly way of fabricating any multilayered thin films, including magneto-optic films.
Elastic Behavior of Nanoparticle Chain Aggregates: Proposed Mechanisms
Authors: Friedlander Sheldon K. , Jang Hee Dong , Ryu Kevin H. 
Published: April 2011

ABSTRACTNanoparticle chain aggregates (NCA) of 7 nm titania particles stretch under tension, and contract when the tension is relaxed. The NCA were stretched across expanding holes produced in the carbon film on an electron micrograph grid. After stretching up to 90%, the NCA broke loose at one end and contracted to a tightly folded chain. This pattern was observed in repeated tests. Mechanisms for this behavior and reasons for its generality are proposed. Implications are discussed for the ductility of nanoparticle ceramics, and the improved properties of rubber due to nanoparticle additives.