bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical and Experimental Analysis of the Low Dielectric Constant of Fluorinated Silica
Authors: Demkov A. , Zollner S. , Liu R. , Werho D. , Kottke M. , Gregory R.B. , Angyal M. , Filipiak S. , Adams G.B. 
Published: April 2011

AbstractFluorinated silica has a dielectric constant lower than that of F-free SiO2 and is a potential interlayer dielectric. We investigate the F-doped SiO2 with ab-initio modeling and various characterization techniques searching to explain the dielectric constant reduction. FTIR transmission and spectroscopic ellipsometry give us information about the ionic and electronic contributions to ε. Nuclear reaction analysis and Auger spectrometry measure F composition. XPS and FTIR provide information on the atomic structure of the film. We use several cells of cristobalite to model fluorinated silica using the electronic structure theory. The ground state geometry, vibrational density of states, electronic band structure, and Born effective charges are analyzed. The calculations suggest that it is the ionic component of the dielectric constant that is mostly effected by the F incorporation.
Study of Dry Photoresist Stripping Processes for Hydrogen Silsesquioxane Thin Films
Authors: Liou Huey-Chiang , Duel Jerry , Finch Victor , Han Qingyuan , Sakthivel Palani , Ruffin Ricky 
Published: April 2011

AbstractThe impact of dry stripping process chemistries on the selective removal DUV photoresist (PR) in the presence of hydrogen silsesquioxane (HSQ) have been studied along with HSQ film properties in order to develop a new, effective process to minimize changes in HSQ during the PR stripping processes. The results show that oxygen-free gas mixtures, specifically H2/N2 gas mixtures, have the best combination of PR:HSQ ash selectivity and minimized changes in HSQ films. However, gas mixtures containing CF4 or O2 greatly reduce PR/HSQ ash selectivity. The process temperature is another parameter that strongly influences ash selectivity. While the higher ash temperature greatly enhances selectivity in oxygen-free gas mixtures, the ash selectivity is only marginally enhanced with increasing ash temperature in the presence of O2. Furthermore, the k-value of HSQ suffers in the presence of O2 due to the oxidization of HSQ films. The data also shows that lower pressure will help to increase ash selectivity. In this study, processes have been demonstrated, which yield a PR:HSQ selectivity greater than 150, while maintaining the dielectric constant of HSQ at 2.8.
Sol-Gel Derived Silica Layers for Low-k Dielectrics Applications
Authors: Acosta Sylvie , Ayral André , Guizard Christian , Lecornec Charles , Passemard Gérard , Moussavi Mehdi 
Published: April 2011

AbstractPorous silica exhibits attractive dielectric properties, which make it a potential candidate for use as insulator into interconnect structures. A new way of preparation of highly porous silica layers by the sol-gel route was investigated and is presented. The synthesis strategy was based on the use of common and low toxicity reagents and on the development of a simple process without gaseous ammonia post-treatment or supercritical drying step. Defect free layers were deposited by spin coating on 200 mm silicon wafers and characterized. Thin layers with a total porosity larger than 70% and an average pore size of 5 nm were produced. The dielectric constant measured under nitrogen flow on these highly porous layers is equal to ∼ 2.5, which can be compared to the value calculated from the measured porosity, ∼ 1.9. This difference is explained by the presence of water adsorbed on the hydrophilic surface of the unmodified silica.
Effects of Curing Temperature on the Mechanical Reliability of Low Dielectric-Constant Spin-on-Glasses
Authors: Toivola Yvete , Cook Robert F. , Saha Chandan 
Published: April 2011

AbstractThe variations in the mechanical properties of a commercial low-k silsesquioxane material with curing temperature are examined, focusing on the transition from the low modulus, high stress, under-cured state to the high modulus, low stress, over-cured state. Film modulus and hardness are determined by instrumented nanoindentation and film dielectric constant is determined by ac capacitance measurements of metal dot structures. The mechanical behavior is correlated with changes in molecular structure via infrared spectroscopy. An implication of the results is that there is an intermediate curing temperature for optimum silsesquioxane interconnection performance.
Reliability of Tantalum Based Diffusion Barriers between Cu and Si
Authors: Laurila Tomi , Zeng Kejun , Seppälä A. , Molarius Jyrki , Suni Ilkka , Kivilahti Jorma K. 
Published: April 2011

AbstractThe reaction mechanisms in the Si|Ta|Cu and Si|TaC|Cu metallization systems are discussed based on the experimental results and the assessed ternary Si-Ta-Cu, Si-Ta-C and Ta-C-Cu phase diagrams. The ternary Si-Ta-N and Ta-N-Cu phase diagrams were also assessed in order to compare the thermodynamic properties of the TaC diffusion barriers to more widely investigated TaNx diffusion barriers. With the help of the sheet resistance measurements, RBS, XRD, SEM, and TEM the Ta barrier layer was observed to fail above 650 °C due to the formation of TaSi2. This was accompanied by the diffusion of Cu through the silicide layer and the resulting formation of Cu3Si precipitates. The stability of the TaC layers was better and the failure was observed above 750 °C due to the formation of Cu3Si and TaSi2. However, interdiffusion of Cu and Si was observed already at lower temperatures due to the presence of pinholes in the TaC layer. This emphasises the importance of the fabrication method and the quality of the TaC layers.
Integrated CVD-PVD Al Plug Process for Sub-Quarter Micron Devices: Effects of Underlayer on the Via Filling and the Microstructure of the Al Film
Authors: Lee Won-Jun , Kim Jung Joo , Kim Jun Ki , Park Jin Won , Kwon Hyug Jin , Park Heung Lak , Rha Sa-Kyun 
Published: April 2011

AbstractThe integrated CVD-PVD Al plug process was successfully applied to a sub-quarter micron device for the simultaneous formation of plugs and wires. The effects of the underlayer on the via filling and the microstructure of the CVD-PVD Al films were investigated. Three types of underlayers were examined in this work: the Ti film deposited by the ionized PVD (I-PVD) method, the MOCVD TiN film stacked on the I-PVD Ti film, and the PVD Al film deposited on the I-PVD Ti film. Excellent via filling was achieved by employing the MOCVD TiN/I-PVD Ti or the PVD Al/I-PVD Ti as an underlayer. When only I-PVD Ti film was used as an underlayer, complete via filling was not obtained, because the CVD Al film sealed the top of vias. The CVD-PVD Al film deposited on the PVD Al/I-PVD Ti underlayer also showed excellent crystallographic texture of Al <111> and surface morphology, which is superior to those of the CVD-PVD Al film deposited on the MOCVD TiN/I-PVD Ti underlayer.
Comprehensive Reactor-Scale Modeling of III-V Ternary Compound Growth by Movpe
Authors: Yakovlev E.V. , Talalaev R.A. , Karpov S. Yu. , Shpolyanskiy Yu.A. , Makarov Yu.N. , Lowry S.A. 
Published: April 2011

AbstractA novel quasi-thermodynamic approach is suggested to simulate surface chemistry in III-V compound MOVPE. Blocking of free adsorption sites by methyl radicals is considered as the mechanism limiting the growth rate at low temperatures. This assumption has provided a good reproduction of experimental data on GaAs MOVPE in various types of reactor. The commercial computational fluid dynamics software CFD-ACE™ has been used to perform a detailed threedimensional modeling of AlGaAs and InGaP deposition in an AIX-200 horizontal reactor. The surface model has been incorporated into the code to obtain the growth rate and layer composition distributions over the substrate. Modeling results demonstrate a reasonable agreement with experimental data.
Nitrogen Incorporation and Growth Kinetics of GaAsN/GaAs Epilayers Grown by MOVPE
Authors: Auvray Laurent , Dumont Hervé , Dazord Jacques , Monteil Yves , Bouix Jean 
Published: April 2011

AbstractThe nitrogen incorporation behavior in GaAs was investigated in the growth temperature range 500-600°C. It was observed that the temperature-dependence of the nitrogen incorporation exhibits two regimes. At 530°C, the nitrogen content x is a nonlinear function of the gas-phase composition indicating a surface-controlled reaction mechanism. The N composition varies slowly with 500°C < T < 560°C with an activation energy of 0.6 eV. For T < 560°C, N decreases exponentially with Ea= 3.7 eV, interpreted in terms of nitrogen desorption. In light of experimental results, we propose a surface kinetic model based on the competitive adsorption of group V precursors.
Simulation Of Polycrystalline Silicon Growth By Pulsed Excimer Laser Annealing
Authors: Kudo Toshio , Ichishima Daiji , Jin Cheng-Guo 
Published: April 2011

AbstractThe dynamic simulation of poly-Si film synthesis has been fulfilled by means of the overlapping irradiation of single- and double-pulsed XeCl excimer lasers shaped into the line beam. A novel model applied to the dynamic simulation is based on the homogeneous nucleation, and the growth and shrinkage velocity of Si grains. The results simulated with the single-pulsed XeCl excimer laser has reproduced the super lateral growth (SLG) phenomenon which occurs in the very narrow range of energy density (the near complete melt regime). The actual energy density dispersion within 5.3% allows us to visualize the multiformity of grain sizes in the cross sectional texture. Standing on the reproduction of the SLG phenomenon by the single-pulsed irradiation, we have obtained the practical knowledge of the growth process of larger grains by the double-pulsed irradiation. We intend that the first pulse has charge of completely melting and the second pulse has charge of adjusting the number of nuclei. The adjustment of the first pulse energy density rather than that of the second pulse energy density leads to the growth of huge columnar grains much larger than the thickness of the Si layer. For the double-pulsed irradiation, the influence of the worst energy density dispersion (each of double pulses has the same fluctuation as the single pulse) is much larger than that of the actual delay time jitter (within 2.5ns) in a sense of the multiformity of grain sizes.
Influence Of Substrate Temperature On Barium Ferrite Films Prepared by Laser Deposition
Authors: Song W.D. , Lu Y.F. , Wang W.J. , Chong T.C. 
Published: April 2011

AbstractInfluence of substrate temperature on properties of barium ferrite films prepared by laser deposition is studied in this paper. The magnetic properties, grain shape and crystalline orientation of the films are discussed for the films prepared by laser deposition with in-situ heating, post annealing and varying substrate temperature. The results show that magnetic properties, grain shape and crystalline orientation of the film deposited with varying substrate temperature are close to the film deposited with post-annealing and different to the film deposited with in-situ heating.
Oxygen Content And Crystallinity Effects in Pulsed Laser Deposited Lanthanum Manganite Thin Films
Authors: Pietambaram Srinivas V. , Kumar D. , Singh Rajiv K. , Lee C. B. 
Published: April 2011

AbstractEventhough colossal magnetoresistance in Lanthanum calcium manganite (LCMO) thin films was known for a long time, the effect of oxygen content and crystallinity on the properties of these films is not clearly understood. It is in this context that we have performed a systematic study of these effects by annealing the films in various ambients. A series of LCMO thin films have been grown in situ on (100) LaAlO3 substrates using a pulsed laser deposition technique under identical conditions. Microstructural characterization carried out on these films has shown that the films are smooth, single phase and highly textured. The films were subjected to the following post deposition treatments: (i) annealing in oxygen at 900°C for 4 hrs, (ii) annealing in argon at 900°C for 4 hrs, (iii) annealing in oxygen at 500°C for 12 hrs, (iv) annealing in argon for 12 hrs and (v) annealing in vacuum at 850°C for half-an-hour. As deposited LCMO films show a transition temperature of 260 K and a magnetoresistance ratio (defined as [R(0)−R(H)/R(H)]) of 190% at 260 K in 5T magnetic field. The samples subjected to 500°C oxygen and Ar anneal have shown no change in the transition temperature and MR ratio. The films subjected to a 900°C annealing in Ar ambient have shown marginal improvement in transition temperature but a drastic improvement in the MR ratio (525%). 900°C oxygen annealed films have shown an improvement in the transition temperature (290 K) and MR ratio (225%) over as deposited films. Vacuum annealed samples have shown deteriorated properties. These results indicate that the metal-insulator transition is related to the oxygen content of the films while the MR ratio is related to the domain size.
Surface Processing And Micromachining of Polyimide Driven by A High Average Power Infra-Red Free Electron Laser
Authors: Kelley Michael J. 
Published: April 2011

AbstractThe long history and wide use of polyimide as a dielectric in the microelectronics industry has made it a favorite material for laser processing studies. The FEL used in the present work delivered picosecond-long 25 microjoule pulses at approximately 3.10 and 5.80 microns. The former is not associated with any strong absorption, while the latter is the strongest absorption band in the IR. This study explored hole drilling and surface transformation of as-made and aluminized DuPont Kapton HN PMDA-ODA polyimde film.
Growth Of ZnO/MgZnO Superlattice On Sapphire
Authors: Muth J.F. , Teng C.W. , Sharma A.K. , Kvit A. , Kolbas R.M. , Narayan J. 
Published: April 2011

AbstractThe optical and structural properties of ZnO/ MgZnO superlattices were investigated by transmission electron microscope, transmission measurement and photoluminescence. The uncoupled wells ranged in thickness from ∼30 Å to 75 Å. Modulation of the Mg content was observed in Z-contrast TEM indicating the alloy composition was periodic. The density of stacking faults in the superlattice was extremely high, however the photoluminescence in the narrowest well case was blue shifted, and substantially brighter than comparable bulk layers of ZnO and MgZnO indicating that the emission was enhanced. Excitonic features were observed in the optical absorption spectra and also revealed that diffusion of Mg from the barrier layers into the well was occurring.
Growth kinetics and diffraction properties of STMV crystals
Authors: Kuznetsov Yu. G. , Malkin A. J. , McPherson A. 
Published: April 2011

ABSTRACTTwo crystal forms, orthorhombic and cubic, of satellite tobacco mosaic virus have been investigated. Atomic force microscopy showed that the orthorhombic crystals were characterized by a high density of point defects, while the cubic crystals were practically defect-free. Nonetheless, orthorhombic crystals diffract to a high resolution of 1.8 Å while the cubic crystals diffract to only about 4 to 6 Å resolution. Differences in the properties of viruses incorporated into the two crystal structures were demonstrated by growth kinetics studies. It appears that physical and chemical treatments applied to protein and virus solutions during their extraction and purification introduce a variety of specific structural changes and that these alterations may then affect the diffraction properties of resultant macromolecular crystals.
Novel Studies of Roughening of the Prism Plane of Ice
Authors: Williamson Ann-Marie , Lips Alex 
Published: April 2011

ABSTRACTA novel technique for examining kinetic roughening of crystals is described, and applied to the study of the prism plane of ice in contact with aqueous fructose solution. The technique can be generally applied to crystals that roughen at low driving forces. Since the residual driving force for growth utilised is that due to Ostwald ripening, this technique also facilitates simultaneous quantification of ensemble growth kinetics and crystal anisotropy during ripening. The driving force required for kinetic roughening, and the step, or ledge, free energy of this plane of ice show an approximately linear variation with temperature over the experimental temperature range −13°C to −17°C. Whilst we can conclude that the thermodynamic roughening temperature (TR) is higher than −13°C, its precise value, and conformance or otherwise of the roughening transition with Kosterlitz Thouless scaling, can not be concluded from the current data set.
Optical Properties of Microcavity Structures using the Organic Light Emitting Materials
Authors: Jung Boo Young , Kim Nam Young , Lee Chang Hee , Hwangbo Chang Kwon , Seoul Chang 
Published: April 2011

ABSTRACTWe investigated the optical properties of Fabry-Perot microcavity with a tris(8- hydroxyquinoline)aluminum (Alq3) organic film by measuring the photoluminescence (PL) and transmittance. An Alq3 layer as an active layer was sandwiched between two mirrors, which were metal or (TiO2|SiO2) dielectric multilayer reflectors. An Alq3 layer on glass, [air|Alq3|glass], showed a PL peak around 513 nm and its full width half maximum (FWHM) was about 80 nm. Three types of microcavity, such as Type A [air|metal|Alq3|metal|glass], Type B [air|dielectric|Alq3|dielectric|glass], and Type C [air|metal|Alq3|dielectric|glass], were fabricated. The result shows that the FWHMs of three Fabry-Perot microcavities were reduced to 15∼27.5, 7∼10.5 and 16∼16.6 nm, respectively, and the microcavity structure is expected to improve the efficiency and tunability of emission spectrum in display.
Location-Controlled Large-Grains in Near-Agglomeration Excimer-Laser Crystallized Silicon Films
Authors: van der Wilt Paul Ch. , Ishihara Ryoichi , Bertens Jurgen 
Published: April 2011

ABSTRACTLarge grains in thin silicon films were grown by controlling the location of unmolten islands, which are left after near-complete melting of the film during excimer laser crystallization. As the initially amorphous film was first transformed in small grain polycrystalline silicon, these islands contain seeds for crystal growth. To get a single large grain, either the number of seeds was reduced to one or a single one was selected from the seeds by a ‘grain filter’. Former was achieved by making a small indentation in the isolating layer underlying the silicon film so that seeds remain embedded in the indentation. Latter was achieved by making a small diameter hole in the underlying isolating layer, which was filled with amorphous silicon. The lateral growth is preceded by a vertical growth phase during which a single grain is filtered from the initial set of seeds present at the bottom of the hole. In the experiment described, highest yield was achieved for samples in which the melt-depth to hole- diameter ratio was largest.
Oxide Charging Effects by PH3/He Ion Shower Doping
Authors: Kim Cheon-Hong , Yoo Juhn-Suk , Park Kee-Chan , Han Min-Koo 
Published: April 2011

ABSTRACTWe report the oxide charging effects on metal oxide semiconductor (MOS) structure caused by PH3/He ion shower doping. The parallel negative shift of flat-band voltage occurred for the ion-doped PETEOS samples even after thermal annealing. When the ion dose was higher, this shift was larger. These results show that a considerable amount of positive charges were induced inside the oxide films after PH3/He ion shower doping process. For the same ion dose, the flat-band voltage shift is larger when the thickness of PETEOS is thicker. When the ion dose was 1.5×1017cm−2and the thickness of PETEOS was 80nm, the shift of flat-band voltage was larger than −7V. We can conclude that PH3/He ion shower doping process induces the positive charges, which result in the flat band voltage shift of MOS capacitors, in the bulk oxide films when oxide films are exposed to ion shower doping.
Location Control of Laterally Columnar Si Grains by Dual-Beam Excimer-Laser Melting of Si Thin-Film
Authors: Ishihara Ryoichi 
Published: April 2011

ABSTRACTThe offset of the underlying TiW is introduced in the island of Si, SiO2 and TiW on glass. During the dual-beam excimer-irradiation to the Si and the TiW, the offset in TiW acts as an extra heat source, which melts completely the Si film near the edge, whereas the Si inside is partially melted. The laterally columnar Si grains with a length of 3.2 μm were grown from the inside of the island towards the edge. By changing the shape of the edge, the direction of the solidification of the grain was successfully controlled in such a way that the all grain-boundaries are directed towards the edge and a single grain expands. The grain-boundary-free area as large as 4 μm × 3 μm was obtained at a predetermined position of glass.
Effects Due to and Derived from Spontaneous Ordering in III-V Semiconductor Alloys
Authors: Zhang Yong , Mascarenhas A. 
Published: April 2011

ABSTRACTTwo interesting and important aspects of spontaneous CuPt ordering in III-V semiconductor alloys, which have only been investigated recently, are reviewed in this paper. The first aspect addresses the statistical effects that should be considered as the most unique consequence of the phenomenon of ordering, more specifically, how ordering affects the alloy fluctuations and hence the physical properties of the alloy. The second aspect tackles some intriguing properties of the domain twins of two CuPt ordered variants, specifically, considering the transmission of a ballistic electron beam through such a domain twin and its analogy to a highly interesting phenomenon, negative refraction, for light.
Synthesis, Characterization and Application of Thin Film Carbon Nanotube Material
Authors: Obraztsov Alexander N. , Volkov Alexander P. 
Published: April 2011

AbstractThe non-catalytical chemical vapor deposition (CVD) method was used to grow carbon thin film material consisting of plate-like nanosized graphite crystallites and multiwall carbon nanotubes with predominant orientation of both species by their crystallographic plane, corresponding to a graphite basal plane, along a normal to the film surface. A number of experimental techniques was used for examination and characterization of the film phase composition, morphology, and electron properties peculiarities. Low-field electron emission with highly density of emission sites and emission current was obtained for the film material and allow to demonstrate their applicability for sealed prototypes of light-emitting devices.
Surrounding effects in single-walled and multi-walled carbon nanotubes
Authors: Buisson Jean-Pierre , Chauvet Olivier , Lefrant Serge , Stephan Christophe , Benoit Jean-Michel 
Published: April 2011

AbstractThe low frequency RBM observed in SWNTs has been proved to probe efficiently their diameter distribution. We have built a model to estimate the interactions between individual nanotubes when arranged in bundles which leads to a RBM upshift of 10 to 20 cm−1. In a PMMA-SWNTs composite, our model shows that an upshift can be also predicted as due to the stress applied by the polymer on the bundles upon breathing. Finally, the interaction between concentric layers in MWNTs can lead to low frequency modes originating from the RBM of individual tubes as observed experimentally.