bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New High Performance CA Resist for E-beam Lithography
Authors: Kwong Ranee , Huang Wu-Song , Moreau Wayne , Lang Robert , Robinson Christopher , Medeiros David R. , Aviram Ari , Guarnieri Richard C. , Angelopoulos Marie 
Published: April 2011

AbstractThree major lithographic applications have emerged for electron beam exposure tools: optical mask fabrication, direct writing for device fabrication, and more recently projection e-beam printing. The traditional mask making process uses poly(butenesulfone) resist. A wet etch process was adopted to generate patterns on chrome. Recently, shrinking dimensions, optical proximity correction features, and the complexity of phase shift masks have forced the industry to a chrome dry etch process. ZEP, a poly(methyl α-chloroacrylate-co-α-methylstyrene) based resist, has been well accepted for most of the >180 nm device mask making. The acceptance of ZEP comes in spite of its low contrast, marginal etch resistance, organic solvent development, and concerns of resist heating associated with its high dose requirements. These issues have spawned interest in using chemically amplified resist (CAR) systems for direct write and mask making applications. We have developed a high contrast resist based on ketal protecting groups, KRS-XE, which is robust against airborne contamination and can be used for all forms of e-beam exposure in both chrome mask and silicon processing. This high contrast resist is processed with aqueous base developer and has a wide bake latitude. The development of KRS-XE has provided the capability of fabricating chrome masks for future generation (< 180 nm) devices and has potential for use with projection beam exposure systems.
Photo and Scanning Probe Lithography Using Alkylsilane Self-Assembled Monolayers
Authors: Sugimura H. , Hanji T. , Takai O. , Fukuda K. , Misawa H. 
Published: April 2011

AbstractAn organic film of a few nm in thickness was applied as a resist for photolithography and scanning probe lithography. This resist film was prepared on an oxide-covered Si substrate through chemisorption and spontaneous organization of organosilane molecules, e.g., n-octadecyltrimethoxysilane. The film belongs to a class of materials referred to as self-assembled monolayer (SAM). A SAM/Si sample was irradiated through a photomask with vacuum ultraviolet (VUV) light at a wavelength of 172 nm. The photomask image was transferred to the SAM through the decomposition of the SAM. Furthermore, we demonstrate nano-scale patterning of the SAM using an atomic force microscope (AFM) with an electrically conductive probe. The SAM was electrochemically degraded in the region where the AFM probe had been scanned. Both the photo-printed and AFM-genereated patterns were successfully transferred into the Si substrates based on wet chemical etching or on dry plasma etching. At present, using these VUV and AFM-based lithographies, we have succeeded in fabricating minute features of 2 μm and 20 nm in width, respectively.
Improved Algorithm to Extract Force-distance Curves from Scanning Force Microscope Data
Authors: Eppell Steven J. , Todd Brian A. , Zypman Fredy R. 
Published: April 2011

AbstractPhysically meaningful near-surface force fields are used to calculate simulated scanning force microscope cantilever deflection data. The simulated data is used to evaluate the ability of a few models to calculate forces from cantilever deflections. The conventional simple harmonic oscillator model is shown to be significantly inaccurate in converting deflections to forces. A bending beam model is developed which accurately converts deflections to forces. This model is shown to be necessary for accurate assignment of physical meaning to the calculated forces under high force gradient conditions.
Ion Projection Lithography for Nano Patterning
Authors: Heuberger A. , Bruenger W. 
Published: April 2011

AbstractAs a result of continuous improvement of the resist process, the experimental ion projector in the Fraunhofer Institute in Berlin (manufactured by Ion Microfabrication Systems, IMS, Vienna) has been able to print 75 nm lines and spaces into 180 nm thick standard DUV resist UV II HS without pattern collapse. A new wafer flow process for more reliable open stencil mask making was developed by IMS –Chips, Stuttgart (Germany), based on SOT wafers. Resistless direct surface modification by He and Xe ions has been tested on metallic and magnetic films in the Berlin projector. This method opens up a new possibility for the production of patterned media for future magnetic storage disks.
Direct-write Electron Beam Lithography: History and State of the Art
Authors: Carr Dustin W. , Tiberio Richard C. 
Published: April 2011

AbstractDirect-write electron beam lithography is a patterning technique that has rapidly evolved over the last 40 years. For many years it has been possible to use electrons to pattern lines with widths as narrow as 10 rum. Recent advances in resist materials, electron sources, and system integration have further enhanced the capabilities. High-sensitivity resists provide substantial increases in the throughput without sacrificing resolution. Thermal field-emission sources improve the stability and reduce the minimum attainable spot size. Modem lithography systems integrate the electron beam column with advanced control electronics, making a system capable of nanometer-scale placement accuracy. In addition to these improvements, the technology is more accessible now than ever before, thanks to the proliferation of lithography systems consisting of modified scanning electron microscopes.
Optimization of the Broadband Reflectance of Graded Multilayers for Hard X-Ray Mirrors
Authors: Ivana Adrian , Brunia Ricardo , Byuna Kyung , Gorensteina Paul , Romaine Suzanne 
Published: April 2011

ABSTRACTMultilayer structures with depth graded spacing can present a high reflectivity in a broad energy bandpass for hard X-rays (>20 keV) if the interface roughness/diffuseness is controlled and minimized. We present an optimization study of several multilayer systems deposited by DC magnetron sputtering on <111> silicon wafer substrates. The material combinations presented in this work are W/Si, W/C, Wsi2/Si, Pt/C, Ni/C, and Mo/Si.
Engineering the Interfacial Chemistry in Metal/Oxide Systems
Authors: PrüBner K. , Pint B. A. , Hou P. Y. , Alexandert K. B. , Tortorellit P. F. 
Published: April 2011

ABSTRACTAlloys designed for high-temperature applications need to form a protective oxide scale to withstand further degradation by oxidation. The importance of the interfacial chemistry for the adhesion of the protective scale was demonstrated in experiments with β-NiAl, iron-aluminides, NiCrAlYs and Ni-based superalloys. Interfaces between alloys both with and without thermal barrier coatings and their thermally grown alumina scales were studied as well as interfaces between alloys and deposited alumina coatings. It was found, that in all cases improved oxidation performance and scale adhesion could be achieved by doping the alloys with reactive elements. The improvement was shown to be due to interfacial segregation of the reactive element. Segregation of sulfur to internal interfaces on the other hand caused scale spallation.
Interface Multiplication Through the Combination of Interface and Lattice Diffusion-Controlled Transformations in Alloys
Authors: Solórzano I. G. , Cohn J. A. , Andrade R. M. 
Published: April 2011

ABSTRACTA procedure for obtaining interface and grain boundary multiplication, without externally applied deformation, in alloy systems is described. It is shown that an essential prerequisite is the occurrence of, and the possibility of controlling, discontinuous precipitation (DP) reactions in the alloy. Several alloy systems have been studied and experimentally generated, in a controlled volume fraction, DP lamellar products in the following model alloys: Al%Ag; Al-22at%Zn; Cu-7at%In and Ni-8at%Sn. The resulting microstructures have been observed in detail through conventional and analytical electron microscopy, confirming that DP is a transformation controlled by solute diffusion along moving grain boundaries. Although the precipitates correspond to the equilibrium phase, the transformation, as a whole, does not reach thermodynamic equilibrium since high-resolution microanalysis of aged and quenched microstructures reveal that a significant amount of supersaturation is retained in the depleted lamellar matrix. In addition, TEM observations have revealed that the DP product, besides generating a high density of interfaces, is able to incorporate a significant amount of strain energy. On the other hand, the dissolution of the lamellar microstructures has been observed to proceed in both continuous and discontinuous fashions. The former, dominating at high dissolution temperatures, is controlled by volume diffusion and gives rise to the development of new microstructures in the original DP colonies: the generation of dislocations and their dynamic re-arrangement into a cellular sub-structure in Al – base alloys; the formation of new grains, in Cu-In and in Ni-Sn alloys. Operating mechanism are proposed and the nature of the driving force for the observed phenomena is discussed in terms of its chemical, interfacial and strain energy components.
Interface Related Strength Phenomena in Two-Phase Titanium Aluminides
Authors: Christoph U. , Oehring M. , Appel F. 
Published: April 2011

ABSTRACTPhase equilibria and transformations in near-equiatomic titanium aluminides lead to the formation of a lamellar structure comprising of the intermetallic phases α2(Ti3Al) and γ(TiAl). Due to the differences in lattice parameters and crystal structure, coherency stresses and mismatch structures occur at various types of semicoherent interfaces present in the material. The present paper reports an electron microscope study of the atomic structure of the interfaces. The residual coherency stresses present at the interfaces were determined by analysing the curvature of dislocation loops which were emitted from the network of interfacial dislocations. The implication of these stresses on creep will be discussed.
Indentation-Induced Debonding of Ductile Films
Authors: Volinsky Alex A. , Clift W. Miles , Moody Neville R. , Gerberich William W. 
Published: April 2011

ABSTRACTThin film adhesion can be measured by means of the nanoindentation technique [1]. In the case of a ductile film (Cu, Al, Au, etc.) well adhered to a brittle substrate, plastic deformation in the film acts as an energy dissipation mechanism, preventing film debonding. Depositing a brittle layer of W (about 1 micron thick) on top of the film of interest increases the driving force for delamination, thus solving the problem [2]. Indentation produces circular delaminations (blisters), sometimes two orders of magnitude bigger than the indenter contact radius. Thin film adhesion was shown to scale with the film thickness, approaching the true work of adhesion of 0.8 J/m2for Cu films less than 100 nm thick [3].Conceptually it is important to know along what interface the fracture occurs during the blister formation. Auger electron spectroscopy (AES) has been used to determine where fracture occurs for different film systems. Cu films on SiO2failed along the Cu/SiO2interface. Fracture of Cu films with a 10 nm adhesion-promoting Ti underlayer occurred along the Ti/Cu interface. Significantly, Ti increased the thin Cu film adhesion by a factor of ten. Blisters were removed from the substrate, and the fracture surface was analyzed. In the case of thin Cu films, crack arrest (fiducial) marks were found upon blister removal, and represent the shape of the crack tip [4]. AFM has been used to determine the geometry of the marks. The main component of the arrest marks is carbon, which comes either from the diamond tip or from the hydrocarbons adsorbed on the newly formed surfaces in the indentation process.
Influence of Processing Method on the Grain Boundary Character Distribution and Network Connectivity
Authors: Schwartz Adam J. , Kumar Mukul , King Wayne E. 
Published: April 2011

ABSTRACTThere exists a growing body of literature that correlates the fraction of “special” boundaries in a microstructure, as described by the Coincident Site Lattice Model, to properties such as corrosion resistance, intergranular stress corrosion cracking, creep, etc. Several studies suggest that the grain boundary character distribution (GBCD), which is defined in terms of the relative fractions of “special” and “random” grain boundaries, can be manipulated through thermomechanical processing. This investigation evaluates the influence of specific thermomechanical processing methods on the resulting GBCD in FCC materials such as oxygenfree electronic (ofe) copper and Inconel 600. We also demonstrate that the primary effect of thermomechanical processing is to reduce or break the connectivity of the random grain boundary network. Samples of ofe Cu were subjected to a minimum of three different deformation paths to evaluate the influence of deformation path on the resulting GBCD. These include: rolling to 82% reduction in thickness, compression to 82% strain, repeated compression to 20% strain followed by annealing. In addition, the influence of annealing temperature was probed by applying, for each of the processes, three different annealing temperatures of 400, 560, and 800°C. The observations obtained from automated electron backscatter diffraction (EBSD) characterization of the microstructure are discussed in terms of deformation path, annealing temperature, and processing method. Results are compared to previous reports on strainannealed ofe Cu and sequential processed Inconel 600. These results demonstrate that among the processes considered, sequential processing is the most effective method to disrupt the random grain boundary network and improve the GBCD.
Dynamic Embrittlement: Quasi-Static Interfacial Decohesion
Authors: Mcmahon C. J. , Bassani J. L. , Mishin Y. 
Published: April 2011

ABSTRACTIn a surprising variety of cases, interfaces in normally ductile materials can undergo timedependent
brittle cracking under the influence of a tensile stress, either applied externally or existing as an internal residual stress. The connecting feature in all these cases is the presence of a surface-adsorbed element that is highly mobile in comparison to the constituent elements of the material. As in the phenomena of diffusion creep and diffusive growth of cavities at high temperatures, the driving force for this cracking is the work done by the tensile stress when a surface atom enters the solid. At temperatures below about 0.5 Tm of the solid, this occurs mainly along grain boundaries. Examples of systems that have been studied in some detail include cracking of alloy steels by sulfur, Cu-Sn alloys by tin, and nickel-based alloys by oxygen. Because the cracking involves diffusive penetration along grain boundaries, the rate of cracking is highly sensitive to grain-boundary structure and composition, and these variables offer opportunities to control the problem. We are aiming at a quantitative understanding of the effects of grain-boundary structure, stress, and temperature on this phenomenon by crack-growth experiments on bicrystals, by atomistic modeling of the stress-driven diffusion, and by micromechanical modeling of the events occurring at the tip of a growing crack.
Angle-Resolved XPS Studies of Interfacial Bonding States in Silicon oxynitrides Fabricated Using Different Thermal Methodologies
Authors: Dang Sanjit Singh , Takoudis Christos G. 
Published: April 2011

ABSTRACTSilicon oxynitride films, fabricated by direct thermal growth and annealing in N2O or NO, were analyzed by Angle-Resolved X-ray Photoelectron Spectroscopy (ARXPS). It is seen that for the samples processed in N2O, N is bonded as Si3N4 only, irrespective of whether the fabrication was done on bare Si or on an oxide pre-grown in O2. But the films processed in NO depict additional bonding arrangements, namely, non-stoichiometric SiOxNy, (Si-)2-N-O, and Si-N(-O)2. These bonding states are found to be concentrated in a higher proportion above the oxynitride/substrate interface. Further, it is seen that annealing of a pre-grown oxide in NO for 30 min incorporates the same bonding states as by direct growth in NO for as long as 120 min. Also, a critical N concentration (between 1.9% and 2.3%) is required for the incorporation of the Si-N(-O)2 structure, observed at 400.7 eV. Besides enhancing the overall understanding of the progress of silicon oxynitridation process in N2O and NO, these findings can help significantly towards developing process-property relationships for incorporation of N with the desired bonding state(s) at specific positions within an oxynitride film.
Low-Temperature Bonding of Ceramics by Sol-Gel Processing
Authors: Barbé C.J , Cassidy D.J. , Triani G. , Latella B.A. , Mitchell D.R.M. , Day A. , Short K. , Bartlett J.R. , Woolfrey J.L. , Collins G.A. 
Published: April 2011

AbstractSol-gel bonding was produced between smooth, clean substrates of silicon and polycrystalline alumina by spin-coating solutions containing partially hydrolysed silicon alkoxides. The two coated-substrates were assembled and the resulting sandwich was fired at temperatures ranging from 300 to 600°C. The coatings and bonded substrates were investigated using SEM, TEM and micro-indentation. For silicon wafers, an optimum water-to-alkoxide molar ratio of 10 and hydrolysis water pH of 2 was found. Such conditions led to relatively dense films (>90%), resulting in bonds with a fracture energy of 3.5 J/m2, which is significantly higher than those obtained using hydrophilic wafer bonding (typically 1.5 J/m2).Poly-crystalline alumina substrates were similarly bonded at 600°C; the opt imised silica sol-gel chemistry yielded interfaces with fracture energy of 4 J/m2.
Selective Area Growth of Magnetic Garnet Crystals by Liquid-Phase Epitaxy
Authors: Yokoi H. , Mizumoto T. 
Published: April 2011

AbstractSelective area growth of magnetic garnet crystals was studied by liquid-phase epitaxy. The garnet layers grown on Ti-masked substrates were analyzed under a scanning electron microscope, and by X-ray diffraction measurements, energy-dispersive X-ray analysis and reflection high-energy electron diffraction. Narrow stripes in the Ti mask were designed to form waveguides by one-step growth. The light waves could be guided within the waveguide fabricated by selective area liquid-phase epitaxy.
Effect of Electric Field on Metal Induced Lateral Crystallization of Amorphous Silicon
Authors: Singla Shivani , Poon M.C. , Chan M. , Qin M. , Chan W.Y. , Yuen C.Y. , Ko P.K. , Wong H. 
Published: April 2011

AbstractThe effects of electric field on the rate of metal induced lateral crystallization (MILC) of amorphous silicon were investigated. Nickel silicide, which is known to be a key species for the low temperature crystallization, was driven by an electric field. As a result, the crystallization velocity of EMILC was much faster than that of conventional MILC methods. Directional crystallization of amorphous silicon thin film was successfully achieved by applying a DC field during heat treatment. The crystallization was performed at different temperatures (500-625°) by employing a thin layer of nickel (30°). The directionality of the resulting crystallization depended on the polarity of the electric field. The lateral crystallization velocity was three to four times faster than MILC when an electric field of 53.5V/cm was applied.
Mesoscopic characterization of the optical property of antiphase boundaries in CuPt-ordered GaInP2
Authors: Ohno Y. , Takeda S. 
Published: April 2011

AbstractWe have developed an apparatus for polarized cathodoluminescence (CL) spectroscopy combined with transmission electron microscopy (TEM), that enables us to obtain simultaneously structural data in higher spatial resolution by TEM and polarized luminescence spectra by CL of the same microscopic area. The polarized-CL/TEM method is very useful to study the optical properties of low-dimensional microstructures in semiconducting materials. We have applied the method to examine the optical property of antiphase boundaries in CuPt-ordered GaInP2 and found, for the first time, the polarized light emission from the APBs whose habit planes are parallel to the (T11) and (1T0) atomic planes.
Depth-Resolved Microspectroscopy of Porous Silicon Multilayers
Authors: Manotas S. , Agulló-Rueda F. , Moreno J. D. , Martín-Palma R. J. , Guerrero-Lemus R. , Martínez-Duart J. M. 
Published: April 2011

AbstractWe have measured micro-photoluminescence (PL) and micro-Raman spectra on the cross section of porous silicon multilayers to sample different layer depths. We find noticeable differences in the spectra of layers with different porosity, as expected from the quantum confinement of electrons and phonons in silicon nanocrystals with different average sizes. The PL emission band gets stronger, blue shifts, and narrows at the high porosity layers. The average size can be estimated from the shift. The Raman phonon band at 520 cm−1 weakens and broadens asymmetrically towards the low energy side. The line shape can be related quantitatively with the average size by the phonon confinement model. To get a good agreement with the model we add a band at around 480 cm−1, which has been attributed to amorphous silicon. We also have to leave as free parameters the bulk silicon phonon frequency and its line width, which depend on temperature and stress. We reduced laser power to eliminate heating effects. Then we use the change of frequency with depth to monitor the stress. At the interface with the substrate we find a compressive stress in excess of 10 kbar, which agrees with the reported lattice mismatch. Finally, average sizes are larger than those estimated from PL.
Optical Characterization of Ion Implanted SIC
Authors: Williams E. K. , Ila D. , Poker D. B. , Hensley D. K. 
Published: April 2011

AbstractWe present the preliminary results of our investigation of producing nanoclusters of gold and tin in 6H-SiC. In this work we study the changes in the linear optical properties as a function of ion fluence and post-implantation heat treatment. The optical absorption is complemented by micro-Raman spectroscopy to investigate lattice damage and recovery. We implanted 1.0 MeV Au and 120 and 160 keV Sn into the Si face of SiC at 30 or 500°C followed by annealing at various temperatures. Using optical absorption spectrophotometry, we determined the location of the absorption band for each metal nanocluster in SiC. Elevated temperature implantation greatly reduced optical absorption due to ion implantation induced defects. Using Mie theory, we determined the index of refraction in the implanted volume and estimated the size of the Au nanoclusters as 5 nm in diameter. Rutherford backscattering analysis of the oxide layer grown during annealing showed an increase of 20 percent in on the implanted side. It was found that the Au clusters occurred only in the oxide layer.
Photo-Induced Current Spectroscopy in Undoped Cvd Diamond Films
Authors: Borchi E. , Bruzzi M. , Lombardi L. , Menichelli D. , Miglio S. , Pirollo S. , Sciortino S. , Serafini D. 
Published: April 2011

AbstractCombined TSC and PICTS measurements have been used to determine the activation energies (Et) and capture cross-sections (σ) of the trap levels inside the bandgap of CVD diamond in the energy range 0.4−0.7 eV. High temperature TSC analysis has been performed to determine the trap parameters in the energy range from 0.9 to 1.3 eV. A fieldmap in the Et−σ plane has been obtained from the combination of the TSC and PICTS data depicting the regions corresponding to two isolated trap levels and to a continuous distribution of states. The concentrations of defects have been calculated from the TSC signals and the measurement of the charge collection efficiency of the diamond samples.