bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microstructure of Epitaxial Al(111)/Si(111) Films Studied by Synchrotron Grazing Incidence X-Ray Diffraction
Authors: Hung H. H. , Liang K. S. , Lee C. H. , Lu T.-M. 
Published: March 2011

ABSTRACTWe report the results of our x-ray diffraction studies on epitaxial Al(111)/Si(111) films prepared by the partially ionized beam deposition technique. Significant changes were observed in intensity profiles for samples before and after annealing. In the in-plane radial scan of Al(220) peak, the shift of Bragg peak is shown due to misfit strain. A weak satellite is also observed which indicates a semicoherent interfacial structure of the annealed film with misfit dislocations. A possible picture of misfit-induced incommensurate structure of Al films is discussed.
Morphology of Ultra-Thin Metal Films Using Infrared Reflection Adsorption Spectroscopy
Authors: He J.-W. , Kuhn W. K. , Goodman D. W. 
Published: March 2011

ABSTRACTThe adsorption of carbon monoxide on ultra-thin films of Cu, Ni and Co on Rh(100) and Mo(110) substrates has been studied using infrared reflection absorption spectroscopy (IRAS). The CO vibrational frequency on Cu/Rh(100) and Cu/Mo(110) at low Cu coverage (∼0.1 ML) shows a blue-shift relative to its gas phase stretching frequency (2143 cm−1). This blue-shift is explained as arising from CO adsorbed on well-dispersed Cu adatoms which are either slightly positively charged due to charge transfer from Cu to the substrate or self-polarized because of a strong Cu-substrate interaction. It is further shown that three-dimensional Cu clusters, well-ordered pseudomorphic two dimensional Cu islands and single Cu atoms are distinctively characterized by the CO IR peaks at 2074 cm−1, 2095 cm−1, and 2162 cm−1, respectively. In addition, it is found that IR spectra of CO adsorbed on Ni/Mo(110) show a remarkable sensitivity to surface structural phase transitions at the Ni-Mo interface.
Step Structures Created on Vicinal Si(111) During Resistive Electrical Heating
Authors: McClelland R. J. , Homma Y. 
Published: March 2011

ABSTRACTScanning reflection electron microscopy was used to examine step structures which form on vicinal Si(111) specimens during resistive electrical heating under ultrahigh vacuum. Heating-current-induced step bunching occurred, forming substantially linear step-bands in specific temperature regions. Small pinning points disrupted the linearity of steps. The interaction between step-bands and large pinning points resulted in the formation of macrosteps, which showed some stability against dispersal during current reversal. Ion-etched grooves influenced step orientation during current-induced step migration.
Reverse Dependence of Ge Surface Segregation on Growth Temperature in Si-Mbe
Authors: Miyao Kiyokazu , Miyao Masanobu 
Published: March 2011

ABSTRACTGe surface segregation on Si(100) and Si(111) substrates during silicon molecular beam epitaxy is studied as a function of growth temperature. During growth, the Ge atoms are partly incorporated into the growing layer and the residuals segregate on the grown surface. The incorporation coefficient cannot be expressed in terms of a simple thermal activation process. That is, the Ge segregation phenomena increase to maxima at around 450°C for the Si(100) substrates and at around 650°C for the Si(111) substrates. Segregation decreases above these temperatures. These reverse temperature dependences enable not only good crystallinity of the heteroepitaxial layer, but also abrupt heterointerfaces. The incorporation coefficients for Si(111) are much larger than those for Si(100), which is explained by a model based on surface migration.
Molecular-Dynamics Study of the Growth of Si1-xGex on Si(100)2×1
Authors: Ethier Stéphane , Lewis Laurent J. 
Published: March 2011

ABSTRACTWe use molecular-dynamics simulations to study the growth of pure Si, Si0.5Ge0.5 and pure Ge on the reconstructed (100) surface of Si. The atoms interact with one another via effective potentials of the Stillinger-Weber form with parameters adjusted such as to describe all types of triplet interactions. Motivated by recent experimental studies of molecular-beam epitaxial films,1 we examine in particular the structure of the deposits for various substrate temperatures. We also examine the relaxation of the structure resulting from high-temperature annealing. Finally, we investigate the interdiffusion of the species at the substrate-deposit interface.
Sputter Deposition of Indium Nitride on The (111) Face of Elemental and Compound Semiconductors
Authors: Morgan J. S. , Kistenmacher T. J. , Bryden W. A. , Ecelberger S. A. 
Published: March 2011

ABSTRACTThe structure, morphology, and transport properties of thin films of InN grown on several cubic semiconductors has been studied as a function of substrate temperature. Films were deposited using rf-magnetron sputtering onto the (111) face of GaAs, Ge, Si and ZrO2. In general, the film structure is such that (00.1)InN parallels the (111) plane of the cubic substrate above some deposition temperature. The in-plane structural coherence duplicates the magnitude of the calculated lattice mismatch between InN and the substrate. Electrical transport properties for growth onto (111) ZrO2 were characterized by n-type carrier concentration and mobilities ranging up to 44 cm2 /Vsec. A morphology-induced decrease in electrical mobility is observed for deposition temperatures above 350°C, as shown by SEM.
Si(100) Surface Preparation by In-Situ or in-Vacuo Exposure to Remotely Plasma-Generated Atomic Hydrogen: Applications to Deposited SiO2 and Epitaxial Growth of Si
Authors: Yasuda T. , Ma Y. , Habermehl S. , Kim S. S. , Lucovsky G. , Schneider T. P. , Cho J. , Nemanich R. J. 
Published: March 2011

ABSTRACTThis paper addresses the in-situ/in-vacuo preparation of Si (100) substrates by hydrogen plasma cleaning prior to low temperature deposition of SiO2, or epitaxial growth of Si or Ge. The paper emphasizes the effectiveness of this type of substrate surface preparation following ex-situ wet-cleaning procedures that include: i) conventional RCA cleans; ii) modified RCA cleans, which incorporate exposure of the Si substrate to ozone, O3; and iii) ozone exposure, with all of these terminated by the removal of sacrificial oxides by dilute HF. We conclude: i) all ex-situ surface cleaning of Si (100) substrates leaves behind sub-monolayer oxygen and carbon surface contamination; ii) that virtually all of the carbon can be removed by exposure of the Si surface to atomic hydrogen at a temperature of <300°C; and iii) that a necessary condition for: (a) the formation of Si/SiO2 interfaces with low defect densities, Dit<l−3×1010cm−2-eV−1, and (b) the growth of epitaxial films of Si; is that the processed Si surface exhibit a 2×1 reconstruction, as detected by LEED or RHEED, following the exposure to atomic hydrogen.
Structural Defects of Silicon Epitaxy and Epi/Substrate Interface Related to Improper In-Situ Surface Cleaning at Low Temperatures
Authors: Yew Tri-Rung , Reif Rafael 
Published: March 2011

ABSTRACTThis paper investigates the defect formation at the epi/substrate interface and epitaxial layers due to an improper in–situ Ar or Ar/H2 plasma cleaning at 500–800 °C Deposition process was carried out immediately after the in–situ cleaning process by ultralow pressure chemical vapor deposition process (ULPCVD) from SiH4/H2. Characteristics of the defects and their relationship with damage or impurity contaminations at the interface are presented. Finally, an optimum cleaning condition which ensures high quality epitaxial growth is addressed.
Two-Dimensional Phase Transitions Associated with a Surface Miscibility Gap in Cu-Ag Alloys
Authors: Liu Y. , Wynblatt P. 
Published: March 2011

ABSTRACTA surface phase transition associated with a surface miscibility gap has been observed on the (111) surface of Cu-Ag alloys both in computer simulations and in experimental measurements of surface composition. This transition is characterized by an abrupt change in surface composition associated with changes in either bulk composition or temperature.The simulations have revealed that the transition from a Cu-rich to a Ag-rich surface phase is accompanied by interesting changes in surface structure. The experiments show that the surface critical temperature lies somewhere between 505 and 560°C.
Ion Beam Damage of Clean Gold Surfaces
Authors: Dunn D. N. , Zhang J. P. , Marks L. D. 
Published: March 2011

ABSTRACTWe investigate the ion beam damage of clean Au (001) single crystals prepared under standard surface science techniques using sputter - anneal cycles. Under initial ion milling conditions using 4 keV Xe ions a significant amount of Xe was implanted into the bulk of the crystal. After a short period of time a Xe super structure developed which yielded 12 Å moire fringes under bright field imaging conditions. With a short anneal the implanted Xe concentration was reduced to the detection limit of Parallel Electron Energy Loss Spectroscopy (PEELS). With extended annealing, the bulk point defect concentration slowly decayed, independent of the surface reconstruction.
Rapid Thermal Annealing of GaAs Films on (001) Si Substrate Grown by Solid Phase Epitaxy Technique
Authors: Choo W.K. , Cho K.I. , Lee J.Y. , Park S.C. , Kwon O.J. 
Published: March 2011

ABSTRACTGaAs layers grown by solid phase epitaxy on (001) Si substrate were subjected to post-growth rapid thermal anneal (RTA) at 700, 800, and 900°C for 10s in a N2 atmosphere. Rutherford backscattering/channeling showed a substantial improvement in crystalline quality of GaAs epilayer after RTA at 800°C. After RTA at 900°C for 10s, stacking faults (and/or microtwins) were eliminated entirely, and the dislocation densities in both the interface region and the film interior were reduced. High-resolution transmission electron micrographs showed a significant change in misfit dislocation structure at the interface after RTA; namely, the 90° pure edge and 60° misfit dislocations were transformed to an evenly distributed array of 90° dislocations at the interface.
Formation of Stacking Faults and Misfit Dislocations During Zn Diffusion-Enhanced Intermixing of a GaInAsP/InP Heterostructure
Authors: Park Hyo-Hoon , Soo Nam Eun , Tak Lee Yong , Lee El-Hang , Yong Lee Jeong , Kwon O'Dae 
Published: March 2011

ABSTRACTThe microstructural degradation of a lattice-matched Ga0.28 In0.72As0.61P0.39/InP heterointerface during atomic intermixing induced by Zn diffusion has been investigated using high-resolution transmission electron microscopy and Auger electron spectroscopy. The localized interfacial stress caused by intermixing appears to create stacking faults in the Ga-mixed InP substrate, and dislocation tangles in the In-mixed GalnAsP layer. The results are attributed to the contrasted effect of tensile and compressive stresses upon the nucleation of partial dislocations from both sides of the intermixed interface. A qualitative model is proposed for the homogeneous nucleation of misfit dislocations from the locally stressed interface.
Stress Orientation Dependence of Dislocation Glide in Epitaxial Films
Authors: Dakshinamurthy S. , Rajan K. 
Published: March 2011

ABSTRACTThe effect of different stresses on the glide of the commonly observed dislocations in epitaxial films is systematically investigated. The possibility of planar dissociation of perfect dislocations and the conditions for their subsequent glide are explored.Slip transfer from one plane to another is affected by the crystal orientation relative to the stress axis. This process is quantitatively analyzed by calculating iso-Schmid factors on a stereographic projection. The results of this model are correlated with those found in the literature.
Effect of the Substrate on Electrical and Microstructural Changes of Coevaporated NiSi2±x(x-0.2) Thin Films
Authors: Grimberg I. , Weiss B.Z. 
Published: March 2011

ABSTRACTElectrical and microstructural changes of NiSi2±0.2 alloy thin films coevaporated on two different substrates were studied as a function of temperature. In-situ resistivity measurements, transmission electron microscopy, and X-ray diffraction were applied. The substrates used were: a) silicon single crystal grown in the [100] direction, and b) similarly grown single crystal but thermally oxidized to a depth of 500 nm. Substantial differences were observed in the morphology and the kinetics of crystallization on both substrates. It was found that the crystallization temperature depends on the composition of the deposited film as well as on the type of substrate. An increase in the Si content of the alloy film deposited on the inert substrate lowers the crystallization temperature, while with the active substrate a rise in the crystallization temperature was observed. The final crystallized phase was identified as NiSia for the alloy films codeposited on Si. For the alloy film deposited on the thermally oxidized substrate NiSi and NiSia were observed when Ni content was higher than 33.3 at.% The crystallization process occurs by homogeneous growth in the film on either substrate. Heating to higher temperature probably results in regrowth of epitaxial MiSis accompanied by the appearance of stacking faults in the alloys deposited on Si (100).
Glancing Angle X-Ray Study of Crystallization of Amorphous Ge at the Ge-A1 Interface
Authors: Heald S. M. , Jayanetti J. K. D. , Budhani R. C. 
Published: March 2011

ABSTRACTThe amorphous to crystalline transformation of Ge in Al/Ge thin film couples has been studied using glancing angle EXAFS, x-ray reflectivity and diffraction. It was found that crystallization occurs at a much lower temperature (118-150 °C) than for bulk Ge, and initiates at the Al/Ge interface. X-ray diffraction studies were made at 152 °C to study the kinetics of the reaction. After an initial period we find good agreement with a square root dependence of the time, characteristic of a diffusion limited reaction.
Evolution of Buried Cobalt Silicide Layers Formed by Co Implantation in Si(111)
Authors: Hsieh Yong-Fen , Hull Robert , White Alice E. , Short Ken T. 
Published: March 2011

ABSTRACTCoalescence and microstructure of buried CoSi2 layers formed by 100 keV Co+ implantation at 350°C into Si(111) are studied. Doses ranged from 1×1016 to 1.6×l017 cm−2. The critical dose (dc) required to form a continuous layer is found to be the same, 1.1±0.1×l017 cm−2, in both (111) and (001) substrates, despite pronounced differences in precipitate morphology. Three types of precipitates are observed in Si(111) during the mesotaxial process: A–type (fully aligned), B0–type (twinned on the (111) plane parallel to the surface), and B1,2,3–type (twinned on one of the three (111) planes inclined to the surface). The fraction of each varies with both the implantation and annealing conditions. Formation of a continuous, twinned (B0–type), buried layer after 1000°C annealing is shown to be possible for the first time by this synthesis technique in samples implanted at dc.
Interfacial Reactions Between Thin Films of Co and InP (100)
Authors: Ben-Tzur M. , Yu K. M. , Haller E. E. 
Published: March 2011

ABSTRACTThe interfacial reactions between thin films of Co and single crystal InP have been studied. The reaction between the Co and the InP substrate already start in the as-deposited state to form In and P rich compounds. During annealing at 250°C for 30 min., phase separation takes place. In addition to unreacted Co, we find Co rich compounds, a Co-P compound in contact with the substrate, and Co-In compound in contact with the metal layer. The general morphology appears to be stable up to 500°C. At higher temperatures (500–600°C) P is released from the substrate. CoP4, Co2P, CoIn2 and In were detected by X-ray diffraction. At this stage the reaction is no longer uniform.
Nanometer Resolution Studies of Microstructural Evolution During the Heteroepitaxy of Ge on Vicinal Si(100)
Authors: Krishnamurthy Mohan , Drucker Jeff S. , Venables J. A. 
Published: March 2011

ABSTRACTWe have studied the initial stages of island formation and coarsening for epitaxial Ge on vicinal Si (100) using in-situ deposition and nanometer resolution biassed secondary electron imaging (b-SEI) in a UHV-STEM. Ge is deposited using MBE techniques on nominally flat Si(100) substrates as well as those misoriented 1° and 5° toward <110>. The temporal evolution of the islanded microstructure can be studied by analysis of computer generated island size distributions. Good statistics can be obtained for islands with radii between 2nm and lOOnm using high resolution b-SE imaging and a large magnification range. Both MBE and Solid phase MBE (SP-MBE) processes have been studied.We explain the evolution of the islanded microstructure in terms of competition for Ge adatoms among the various available sinks. For the MBE case, control of diffusion distances by varying the substrate temperature has allowed us to identify effects related to coherently strained and highly dislocated Ge islands as well as contaminant particles. In all cases, coherently strained Ge islands appear to be the weakest sinks and contaminant particles the strongest. Metastable growth of the intermediate layer during interrupted depositions at 375°C may be a direct consequence of an energy cost for incorporating adatoms into coherently strained islands. For depositions at higher temperatures, strong adatom sinks influence nucleation densities and size distributions of Ge islands by reducing the effective supersaturation. Island size distributions analyzed for the case of room temperature deposition in the early stages of coarsening also show evidence of effects due to coherently strained islands. These size distributions evolve from an initial distribution to one with increasing number of large islands while the distribution of the smaller islands (< 10nm radius) remains constant.
Development of Polyphenylene—Oxide Film for Selective Encapsulation in Microelectronics
Authors: Ton-That Y-Tri , Troyk Philip R. 
Published: March 2011

ABSTRACTCorrosion control of microelectronic devices which operate in high humidity is essentialfor reliability. A selective encapsulation method based on the electrochemical synthesisof polyphenylene—oxide (PPO) film has been investigated. The monomer is electrochemically polymerized and simultaneously deposited on the device surface to form an adherent coating. Electrical properties of PPO coatings on gold substrates subjected to water immersion and voltage bias were measured. The influence of coating thickness, adhesion promoter, and substrate cleanliness were investigated and optimized. In the early stage of biased immersion, coating failure was mainly caused by defects at the metal—polymer interface, whereas failure after extended testing was due to the slow degradation of polyphenylene—oxide in an aqueous media.
Hardness of Thin Polymer Coatings on Glass
Authors: Ritter J. E. , Sioui D.R. , Gu W. , Lardner T.J. 
Published: March 2011

ABSTRACTFor a soft coating on a hard substrate the overall hardness of the coating/substrate system increases substantially when the indenter penetrates into the substrate sincethe substrate can now directly support some of the indenter load. A model for the overall hardness is developed by accounting for the indentation load shared by the coating andsubstrate. This model accounts for the additional load supported by the coating due to the pile-up of coating material underneath the indenter. The model predicts the overall hardness as a function of coating and substrate bulk hardness and coating thickness. Comparison of the model to experimental data for two polymer coatings (epoxy and epoxy acrylate) on soda-lime glass substrates shows good agreement.
Ceramics and Glass-Ceramics in Electronic Packaging
Authors: Tummala Rao R. 
Published: March 2011

ABSTRACTAn overview of ceramic packaging as it evolved over the last two decades from dual-in-line packages to state-of-the-art multilayer multichip packages ispresented. IBM's 69 layer glass-ceramic/copper multilayer multichip substrate with dielectric constant of 5.0, thermal expansion exactly matching silicon and exceptional dimensional control is summarized.
Overview of High Performance Packaging Materials
Authors: Johnson Barry C. 
Published: March 2011

ABSTRACTHigh Performance Integrated Circuits form the basic building blocks of modern electronic systems that are designed to process ever larger numbers of electrical signals at greater signal velocity and fidelity. In such applications, each circuit must be packaged in order to provide it with necessary mechanical support, environmental protection, electrical interconnection and thermal cooling. The package, however, can also impose certain constraints on the chip. It can degrade electrical performance, add size and weight, introduce reliability problems and increase cost. Thus, packaging can be viewed as a complex balance between the provision of desired functions and the reduction of associated constraints.The ability to strike a proper balance has become increasingly difficult in recent years due to the relentless march of integrated circuits toward higher levels of complexity, size, speed, heat flux and customization. It is anticipated that the continuing evolution of high performance circuits and systems will soon be limited by the package designs and materials-of-construction, rather than by the devices on the semiconductor chip.The intent of this talk is to provide a brief overview of high performance packaging and the related materials issues. The approach is to (a) present the forecasted trends in relevant circuit performance characteristics, (b) discuss the impact of these characteristics on current chip and board level packaging methods, and (c) present new package and materials concepts that might furnish potential solutions to the developing circuit-package performance gap.
Interfacial Studies on Cr and Ti Deposited on Benzocyclobutene (BCB) Film
Authors: Paik Kyung W. , Cole Herbert S. 
Published: March 2011

ABSTRACTInterfacial characteristics such as chemical reaction, metal diffusion, and morphology were investigated for Cr/BCB and Ti/BCB structures. Using Auger and XPS depth profiling, the formation of Ti carbide and Cr oxide was confirmed at the metal/BCB interface. Annealing at 250 °C for extended time periods resulted in diffusion of Cr and Ti into the BCB and subsequent formation of CrSi2and Ti-Si compound precipitates. The reaction is a thermal diffusion controlled process which was dependent on time and temperature. It was also found that Ar backsputtering treatment on BCB film before metallization was found to roughen the surface resulting in metal spikes which penetrate into the BCB film.
Effect of Geometry on the Fracture of Metal-Polymer Interfaces
Authors: Chiu Shih-Liang , Ho Paul S. 
Published: March 2011

ABSTRACTThe fracture behavior of the Au(Cr)/PMDA-ODA interface was investigated using a stretch deformation method. The study has been focused on thc effects of metal dimension on the delamination behavior, the fracture morphology, and energy dissipation rate of the interface. The delamination behavior shows complex geometrical dependence, with changes observed in the magnitude of strain at failure as well as the progression of the fracture process. The fracture morphology and energy dissipation rate also show apparent dependence on the metal dimensions. The crack growth, as examined by the rate of energy dissipation, seems to consist of thrce stages: crack initiation, crack growth and post growth. Only the growth region exhibits a constant dissipation rate and the fracture energy determined in this stage is in good agreement with that obtained from energy balance. These results can be attributed to the change in the mechanical coupling between the metal and the polymer layers, which was evaluated using a finite element analysis with plastic deformation taken into aiccount.