bluuebunny/crossref_metadata_2025_split huggingface dataset:
To the Influence of the Wafer Edge in RTP
Authors: Zöllner Jens-Peter , Patzschke I. , Pietzuch V. , Pezoldt J. , Eichhorn G. 
Published: March 2011

ABSTRACTThe goal in Rapid Thermal Processing is the realization of homogeneous and stable temperature distribution across the wafer.Due to the wafer edge an additional heat loss occurs, which leads to temperature decrease near the wafer boundary. This can be the origin for layer thickness inhomogenities and defect generation. For successful compensation it is necessary to know why such a temperature gradient exists.The heat transfer at the wafer edge was investigated by using computer simulation.The results confirmed by experimental data in the pressure range of 1.. 760 Torr are discussed and criteria for the compensation of the temperature gradient near the wafer edge are developed.
Stress and Warpage Studies of Silicon Based Plain and Patterned Films During Rapid Thermal Processing (RTP)
Authors: Thakur R.P.S. , Martin A. , Fackrell W.T. , Barbour R. , Kawski J. L. , Perroots L. 
Published: March 2011

ABSTRACTSingle wafer rapid thermal processing (RTP) is emerging as a key player in the processing of advanced sub-half micron memory devices. The high temperature processing of large diameter silicon wafers can create sufficient thermal stress for generation of dislocation, slip, and gross mechanical instability of the wafer. The aforementioned factors may lead to loss of device yield, dielectric defects, and reduced photolithographic yield due to degradation of virtual wafer flatness. Moreover, the loss of geometrical planarity of wafer due to warpage can make it impossible to process a wafer or can lead to self-fracture of the wafer.In this paper we present the warpage and stress results of our study on plain and patterned structures that were subjected to RTP at different stages of the CMOS process flow. Experimental results have been gathered with full wafer scanning technology using non-contact capacitive probes to measure more accurate global stress values. The stress and warpage values on the patterned wafers could be measured accurately without any light scattering effects and destructive interference. It is reported that the thermal processing creates significant variations in shape change around the wafer which could be identified using the full wafer data set acquired using this evaluation technique. We have successfully tracked variations in film stress for both plain and patterned structures as a cumulative effect and correlated it with the overall wafer warpage. The effects of incoming wafer warpage, ramp rate in RTP, and high stress nitride films on the overall wafer warpage are also reported.
Simulation of Rapid Thermal Processing Equipment and Processes
Authors: Lie Kun-Ho , Merchant Tushar P. , Jensen Klavs F. 
Published: March 2011

ABSTRACTWe present finite element simulations of fluid flow, heat transfer, and chemical reactions in axisymmetric rapid thermal processing (RTP) configurations. A new approach to simulating radiation heat transfer between lamps, substrates, and system walls is described. The method accounts for multiple reflections and readily allows the inclusion of temperature, radiation wavelength, and materials specific emissivity parameters. The influence of system geometry, lamp power profile, substrate and wall emissivity parameters, and process gas flow upon RTP performance characteristics is illustrated through examples. Transient flow and heat transfer simulations are used to identify operating conditions where flow recirculations are avoided. The further use of physically based models in the design and optimization of RTP systems is discussed.
Three Dimensional Temperature Uniformity Modeling of a Rapid Thermal Processing Chamber
Authors: Knutson Karson L. , Campbell Stephen A. , Dunn Floyd 
Published: March 2011

ABSTRACTA 3-dimensional model of an industry standard Rapid Thermal Processing (RTP) chamber (AG Assoc. 4108 Heatpulse) has been created. The chamber consists of a quartz sleeve containing a 200mm wafer surrounded by a polysilicon thermal guard ring. The wafer is heated by tungsten filament lamps which are assumed to radiate according to Boltzmazi' gray-body model. Detailed radiation transfer among ∼4000 finite surfaces is considered as well as Navier-Stokes solution of an energy balance to determine chamber temperature distributions.Experimental wafer temperature distributions have also been obtained using an 8 inch wafer imbedded with 17 thermocouples and from oxide growth measurements at 700 and 1100 Centigrade respectively. The model predictions are within 1% of the experimental data at both low and high temperatures with the only parameter being the lamp filament temperature. The model is used to demonstrate the ability to examine non-symmetric effects of varying specific chamber properties (i.e. lamp power output, wall reflectivity), as well as transient phenomena.
Boron Diffusion in Fluorine Preamorphized Silicon During Rapid Thermal Annealing
Authors: Kinoshita H. , Huang T. H. , Kwong D. L. , Bakeman P. E. 
Published: March 2011

ABSTRACTThe effect of fluorine preamorphization on boron diffusion and activation during rapid thermal annealing (RTA) has been investigated. Compared with low energy B or BF2 implant into crystalline Si, F preamorphization suppressed the transient enhanced diffusion of B and increased dopant activation. Results show that the tail diffusion was absent, and thus the junction depth of the RTA annealed sample was established by the as-implanted B profile. Secondary ion mass spectroscopy and cross-sectional transmission electron micrograph results show F accumulation near the surface and at end-of-range defects. The interaction of F with defects is believed to reduce the B diffusion during RTA.
Investigation of Proximity Rtd for Submicron Junctions in Vlsi Si Devices
Authors: Zagozdzon-Wosik W. , Grabiec P. , Romero-Borja F. , Wood L. T. , Lux G. 
Published: March 2011

ABSTRACTProximity rapid thermal diffusion is presented as a doping process for fabrication of very shallow junctions. The kinetics of Si doping with B, P and As is investigated using sheet resistance measurements, secondary ion mass spectroscopy and FTIR analyses. The efficiency of doping is affected by the dopant transport in the SOD which depends on the structure and composition of the SOD.
Rapid Thermal Annealing for Electrical Activation in The Fabrication of GaAs Mesfet
Authors: Choi S.W. , Yang J.W. , Koak B.H. , Cho K.I. , Park H.M. 
Published: March 2011

ABSTRACTRapid thermal annealing (RTA) has been employed for the electrical activation of shallow n-channel layer by Si+ implantation in the fabrication of GaAs MESFET. To prevent considerable outdiffusion of gallium and arsenic from GaAs substrate during annealing, encapsulating layers such as SiNx and SiNx/SiO2 are deposited. The SiNx/SiO2 double dielectric encapsulant is shown to be more effective to improve the electrical activation. Depending on RTA temperature between 900 and 950°C, the maximum activation efficiency exhibits 77% at the implanted energy of 70 keV and the dose of 5x1012 cm−2. SIMS analyses show the reduction of the hydrogen contained in the silicon nitride and no outdiffusion of Ga and As during RTA. It also shows the sharp Si-profile after RTA at 950°C, 30 sec. The MESFET fabricated using activation with RTA provides better transconductance than that with furnace-annealed activation.
Poly-Si Thin Film Transistors Fabricated with Rapid Thermal Processing
Authors: Campo E. , Pedroviejo J.J. , Scheid E. , Bielle-Daspet D. , Messaoud A. Yahia , Sarrabayrouse G. , Martinez A. 
Published: March 2011

ABSTRACTIn this work, we studied the rapid crystallization and the rapid tbermal oxidation of amorphous silicon films deposited at 465°C by low-pressure chemical vapor deposition (LPCVD) from disilane. The crystallization is well-controlled and the thermal bugdet is reduced compared to conventional processes. Results concerning the electrical and structural characteristics of poly-Si thin film transistors (TF7) are given. Furthermore, we obtained after plasma hydrogenation better mobilities in the case of rapid thermal processing (RTP) (μp-61 cm2/V.s, VT−8.3 V, subtbreshold slope−-0.8 V/decade, ION/IOFF− 1. 106 for p-type and μn-80 cm2/V.s, VT−3. 7 V, subthreshold slope−1.4 VWdecade, ION/IOFF−5.104 for n-type) compared to conventional processing performed at 600°C. The mobilities are improved by a factor of 2 to 3 despite the smaller grain size in the silicon films. We also showed a correlation between the optical absorption coefficient k (at 405nm) and the mobility wbicb appears not only dependent upon, the grain size but also upon the grain quality (grain boundaries and defects inside the grain).This study shows that the structural and electrical properties of thin-films and oxides fabricated by RTP are at least as good as those obtained by conventional techniques.
Ultrathin Gate and Capacitor Dielectric Formation Using Single- Wafer Processing
Authors: Thakur R.P.S. , Ahmad A. , Ditali A. , Martin A. , Kermani A. , Galewski C. , Mcintosh R. , Legler K. 
Published: March 2011

ABSTRACTVarious ultrathin gate and capacitor structures were formed in a single wafer, lamp heated, reduced pressure, cold wall CVD reactor. Sequential processes including in-situ rapid thermal cleaning, surface passivation, and dielectric formation for capacitor structures was achieved at reduced pressure using pure ammonia. Three types of dielectric films were fabricated: pure thermal oxide, oxynitride, and silicon nitride. The films were grown using pure dry oxygen, nitrous oxide, and silane/ammonia chemistries, respectively. Excellent uniformity across the wafer was observed for dielectric films of different thicknesses. The RTCVD-based films exhibited improved characteristics for leakage and device drive. The TDDB data indicates that the short and long term reliability of the gate and capacitor dielectric films formed with the singlewafer process was better than that obtained with furnace-grown films. Auger electron spectroscopy and ellipsometry techniques were used to correlate film composition with processing conditions. In this paper we present the growth kinetics, composition, and thickness uniformity data and the electrical results of single-wafer processing.
Self-Aligned Epitaxial Cosi2 Formation From Multilayer Co/Ti-Si(100) by a Two-Step Rta Process
Authors: Hong F. , Patnaik B.K. , Rozgonyi G.A. , Osburn C.M. 
Published: March 2011

ABSTRACTWe have extended our recent work on nano-scale CoSi2 formation from Co/Ti(O)multilayers on Si(100) to a self-aligned epitaxial CoSi2 structure produced by a two-step RTA annealing process. Parallel oxide stripes/Si windows were produced on a 4-inch Si(100) wafer by thermal oxidation and patterning. Six layers of 20nm Co and 10nm Ti were deposited sequentially on the patterned wafers with Ti as the first layer. The wafers were then annealed at 550°C to 700°C in N2 using a lamp RTA system. XTEM and RBS showed that a 25nm CoSi layer formed at the interface after a 650°C, 60sec annealing. The unreacted layers above it and oxide were selectively removed leaving a residual amorphous layer and CoSi intact on the patterned Si substrates. A second annealing at 900'C for 10sec produced 20nm of epitaxial CoSi2 covered with an ∼10nm CoxTiy(O)Siz surface layer. The epitaxial CoSi2 layer was thermally stable up to 1000°C, had a resistivity of ∼20μΩ-cm, and consumed ∼300Å of Si, thereby satisfying the most stringent deep submicron device contact scaling requirements.
The Impact of Pre-Silicidation Heat Treatment and Dopant Effects on the Thermal Stability of Cosi2 Polycide During Rapid Thermal Annealing
Authors: Chen W. , Lin J. , Banerjee S. , Lee J. 
Published: March 2011

ABSTRACTThe effects of heat treatment of polysilicon and amorphous Si films on their microstructure and thermal stability of polycides formed on these films have been studied. The number of grain boundaries decreases after pre-silicidation heat treatment in polysilicon due to grain growth but increases in amorphous Si due to nucleation. Since the thermal stability of CoSi2 polycide films was found to be closely related to the number of grain boundaries in the underlying silicon substrate, pre-silicidation heat treatments degrade the thermal stability of CoSi2 on as-deposited amorphous Si and improve the thermal stability of CoSi2 on asdeposited polysilicon. Doping does not have as pronounced an effects as substrate microstructure on CoSi21 polycide thermal stability, especially when dopants are introduced after silicidation by ion implantation.
Study of Chemical Interactions at the Stainless Steel / Polymer Interface by Infrared Spectroscopy
Authors: Thery S. , Mantel M. , Jacquet D. 
Published: March 2011

AbstractThe interfacial interaction of a thermoplastic copolymer ethylene-maleic anhydride with stainless steel has been studied by infrared spectroscopie techniques (FTIR) in order to improve the durability of steel/polymer association, by modifying formulation of polymer or surface treatment of stainless steel.In order to be successful, an analytical methodology has been established. Interfacial chemical actions of maleic anhydride with stainless steel are simulated through thin layer of succinic anhydride on polished metal surface. FTIR spectroscopie (grazing angle) permit a direct access ot interphase for identifying new bounds between organic and metallic compounds.Interaction of succinic anhydride with the polar OH groups of the oxidized metal surface follawed a reactional mechanism which can be described by two steps:- opening of the anhydrid ring for reacting with adsorbed water and formation of acid group (-COOH),- reaction of acid group with hydroxylic fraction of metal surface and formation of carboxylate anion (-COO-) groups.
Interfacial Bonding Mechanisms in Carbon Fiber/Pmr-15 Composites
Authors: Serrano A. M , Jangchud I. , Eby R. K. , Bowles K. J. , Jayne D. T. 
Published: March 2011

AbstractX-ray photoelectron spectroscopy (XPS), tensiometric wetting, and atomic force microscopy (AFM) were used to investigate the surfaces of PAN based carbon fibers. Percent weighted dipole moments (%WDM) were computed from the deconvoluted core level carbon XPS peaks. Tensiometric wetting separated the polar and dispersive components of the fiber surface energies thus allowing the computation of % polar energies. AFM provided quantitative measurements of the fiber surface rugosities. Scanning electron microscopy (SEM) revealed adhesive interfacial fractures for PMR-15 (polyimide) composites of fibers with low %WDM and % polar energies; cohesive fractures for those with high %WDM and % polar energies. Increasing interlaminar shear strengths correlated with increasing %WDM and % polar energies. The fibers with higher %WDM also had rougher surfaces which probably expose more graphite basal plane dipole sites in addition to providing mechanical interlocking.
Microstructures of Chemically Polymerized Ultrathin Polypyrrole Films
Authors: Chu Xi , Chan Vivcent , Schmidt Lanny D. , Smyrl William H. 
Published: March 2011

AbstractThe microstructures of chemically polymerized polypyrrole 100 to 800 Å films were studied by transmission electron microscopy (TEM). The fibers are embedded in an amorphous matrix which forms a self-reinforced composite. The shape of the fibers ranged from thin rods to ellipsoids depending on the preparation conditions. The density and size of the fibers were affected by the polymerization time and the concentration ratio of pyrrole and oxidants. Polypyrrole fibers were aligned along the thin film plane and were randomly oriented in the plane. The two-dimensional orientation of the crystalline fibers produced strongly anisotropic electrical properties in the thin films. It has been found that by properly adjusting the polymerization condition, it is possible to obtain the polypyrrole conducting ultra thin films with improved mechanic and electric properties.
High Performance Processing for High Performance Polymers
Authors: Lusignea Richard , Blizard Kent , Rubin Leslie 
Published: March 2011

AbstractHigh performance polymers require new processing technologies to achieve their full potential properties. The strength, stiffness, coefficient of thermal expansion, and barrier properties of LCPs and blends are strongly dependent on processing. The use of biaxial shear flow during extrusion, elongational strain after extrusion, electromagnetic field effects, and thermal treatment will be discussed with respect to LCP film processing. The effect of these conditions on the properties of films will be reviewed and applications for high barrier containers, electronic substrates and lightweight structures will be described.
Realization Of X-Ray Lithography Masks Based On Diamond Membranes
Authors: Ravet M. F. , Gicquel A. , Anger E. , Wang Z. Z. , Chen Y. , Rousseaux F. 
Published: March 2011

AbstractDeposition parameters acting on nucleation and growth local conditions have been optimized in a bell jar microwave plasma reactor to obtain polycrystalline diamond thin films compatible with X-ray membrane requests. The microstructure and the chemical quality of the films were estimated by SEM and Raman spectroscopy respectively, the roughness was evaluated by AFM experiments and the residual stress was deduced from the substrate deflection method. Membranes were obtained by removing the silicon substrate on 15 mm diameter circular windows. The optical transparency depending on deposition conditions was optimized up to 65% at 630 nm for 1 μm thickness. A high resolution additive mask process, based on well taut membranes and low stress electroplated gold absorber, was carried out. Micrometric and submicrometric mask patterns were generated in photoresists both by electron beam lithography with a nanopattern generator and by X-ray lithography using the synchrotron radiation facility implemented at LURE-Orsay. Despite the diamond films roughness of the order of 30 nm, well defined dots and lines as narrow as 100–200 nm could be obtained.
Materials For Laser-Plasma X-Ray Source Targets Applicable To Lithography
Authors: Chaker M. , Pelletier J.F. , Kieffer J.C. 
Published: March 2011

AbstractIn recent years, several X-ray lithography experiments involving laser plasma sources have been reported. The high X-ray conversion efficiency (η – 10%) in the keV range observed in various laboratories, using high laser intensities (I > 5 × 1012 W cm−2), has already made these sources an attractive alternative to the electron storage rings for X-ray lithography in proximity printing (XRL). In addition, X-rayproduction in the region around 130 Å has also been investigated at intensities of about 1011 W cm−2 for applications to X-ray Projection Lithography (XRPL). Conversion efficiency up to 1% into a 3 Å bandwidth has been demonstrated. In principle, a large variety of X-ray spectra can be obtained from a laser plasma source depending on the laser-target parameters. However, high conversion efficiencies, in a given spectral range, can only be achieved under specific plasma conditions (target atomic number, plasma temperature, plasma volume and spatio-temporal expansion...). This leads to some restrictions in possible target materials and irradiation conditions (laser wavelength, laser intensity, pulse duration). In this paper, we will discuss this physical aspect basing our analysis on both the theoretical and experimental studies of the X-ray spectra in different X-ray energy ranges and for various target atomic numbers. In addition, we will examine issues related to the laser plasma X-ray source design for both XRL and XRPL applications.
Properties Of SiC Film As X-Ray Mask Membrane
Authors: Yamaguchi Yoh-Ichi , Annaka Norimichi , Shoki Tsutomu , Amemiya Isao , Nagasawa Hiroyuki , Kosuga Hiroyuki , Nagarekawa Osamu 
Published: March 2011

AbstractMany properties of LPCVD SiC film as X-ray mask membrane have been investigated in detail. The film has an atomic ratio of 1.0 and negligible impurities, and was found to be damage-free to SR X-rays up to 500 KJ/cm2. An integrated transparency of 1.05 μm thick SiC membrane for SR X-rays was measured to be 76%. The interference peak at 633 nm of optical spectrum has given the membrane of around 1.0 μm in thickness the transmittance peak of 70% and increased to more than 80% after an AR coating or planarizations by polishing and etching-back. The attainable transmittance was found to be limited to about 84%, theoretically and experimentally, due to the absorption of the membrane. The peak transmittance of 87% is obtainable by the AR coating on the polished SiC membrane. The internal stress was found to be independent of thicknesses above 0.6 μm and the measured Young's modulus is 4.5×1011 Pa irrespective of the thickness and stress. Some extremely polished (0.1 nm Ra) and all the etched-back membranes studied withstood breakage at the pressure as high as the as-deposited ones. The stress uniformity in 30 mm square of the membrane was found to be ± 10 % by measuring five local stresses with a bulge method.
Materials Issues In X-Ray Mask Repair by Focused Ion Beams
Authors: Melngailis John 
Published: March 2011

AbstractIn x-ray mask repair high Z absorber features, such as gold or tungsten, must be removed or added. The main challenges are the small lateral dimensions (0.25 μm and below) and the thickness of the absorbers (˜ 0.5 μm) The focused ion beam appears to be the best tool developed to meet this challenge. Unwanted features are removed by ion milling while missing absorber is reconstructed using ion induced deposition from a locally piped-in precursor gas. The high aspect ratio of the features complicates both of these processes. Milling away 0.5 μm thick absorber can lead to redeposition of the sputtered material on neighboring features. The crystal grains of the absorber mill at different rates depending on orientation which results in nonuniform features. A possible alternative which only works with W absorber is to use ion assisted etching. In ion induced deposition a precursor gas such as dimethylgold hexafluoro acetylacetonate is provided by a capillary tube aimed at the region scanned by the ion beam. The incident Ga+ ions, usually at energies in the 25–100 keV range, dissociate the adsorbed precursor molecules leaving a deposit of gold mixed with carbon. The carbon content can approach 50 atomic % resulting in an x-ray attenuation which is about one half of that of pure gold. A number of unexplored materials science issues are associated with mask repair including: the reduction of the carbon content, redeposition both from milling and from induced deposition, milling as a function of crystal orientation and energy, and deposition of high aspect features. The technology is well enough developed so that mask repair of 0.25 μm features can be considered. However, a better understanding of the materials science aspects of x-ray mask repair will help to advance the state-of-the-art.