bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extending the Use of NO Dielectrics for DRAM by Ultrathin Silicon Nitride RTCVD with In Situ Ammonia and Hydrogen Pre-Deposition Surface Conditioning
Authors: Tiner Paul A. , Khamankar Rajesh B. , Johnston Clark D. , Park Song C. , Pas Michael F. , Violette Katherine E. , Wise Rick L. 
Published: April 2011

ABSTRACTThe use of thin nitride/oxide (NO) stacked dielectrics is common in DRAM storage node structures today. The cell capacitance can be increased without increasing the cell plate area by decreasing the thickness of the dielectric. Combinations of novel storage node structures, textured electrode surfaces, and very thin NO films (equivalent oxide thickness equal <30 Angstroms) are being characterized for use in 256 Mb and 1 Gb DRAM devices as an alternative to premature use of high k dielectric materials. However, the native oxide formed on the surface of the polysilicon bottom electrode prior to dielectric nitride deposition in a standard LPCVD furnace reactor causes the leakage current and reliability properties of the dielectric to degrade for very thin films. Using a vacuum load-locked RTCVD single-wafer reactor with appropriate in situ ammonia and hydrogen pre-deposition surface conditioning, the native oxide can be eliminated and very thin nitride films of much higher quality can be deposited. A comparison between standard batch LPCVD processing and single-wafer RTCVD for silicon nitride deposition has been done and electrical characteristics (including leakage current and time dependent dielectric breakdown) of the films have been measured. These results indicate that use of NO dielectric films may be extended 1–2 more generations of DRAM devices. This will allow more time for improving the quality of high k dielectric films.
Rapid Thermal Processing of III-Nitrides
Authors: Hong J. , Lee J. W. , Vartuli C. B. , MacKenzie J. D. , Donovan S. M. , Abernathy C. R. , Crockett R. V. , Pearton S. J. , Zolper J. C. , Ren F. 
Published: April 2011

ABSTRACTTransient thermal processing is employed for implant activation, contact alloying, implant isolation and dehydrogenation during III-nitride device fabrication. We have compared use of InN, AlN and GaN powder as methods for providing a N2 overpressure within a graphite susceptor for high temperature annealing of GaN, InN, A1N and InAlN. The AlN powder provides adequate surface protection to temperatures of ∼1100°C for AlN, > 1050°C for GaN, ∼600°C for InN and ∼800°C for the ternary alloy. While the InN powder provides a higher N2 partial pressure than AlN powder, at temperatures above ∼750°C the evaporation of In is sufficiently high to produce condensation of In droplets on the surfaces of the annealed samples. GaN powder achieved better surface protection than the other two cases.
Rapid Thermal Annealing and Oxidation of Silicon Wafers with Back-Side Films
Authors: Fiory A. T. 
Published: April 2011

ABSTRACTTemperatures for lamp-heated rapid thermal processing of wafers with various back-side films were controlled by a Lucent Technologies pyrometer which uses a/c lamp ripple to compensate for emissivity. Process temperatures for anneals of arsenic and boron implants were inferred from post-anneal sheet resistance, and for rapid thermal oxidation, from oxide thickness. Results imply temperature control accuracy of 12°C to 17°C at 3 standard deviations.
Improved Methods for Evaluation of Rapid Thermal Processors
Authors: Speranza Tony , Nakos Jim , Medina Val , Banerjee Sanjay , Williamson Gary , Lysaght Pat , Lindholm Don 
Published: April 2011

ABSTRACTSEMATECH has worked with numerous commercial suppliers of RTP systems on both evaluation and development projects. It has adopted standardized methods which minimize monitor wafer impact and improve system characterization. RTP temperature control requirements are projected to tighten with each successive technology node (1). This paper discusses issues concerning performance evaluation of Rapid Thermal Processors (RTP).
Emissivtty Studies on Polycrystalline Silicon and a-Si / SiO2 / Si
Authors: Chen W. , Oh M. , Abedrabbo S. , Tong F. M. , Schmidt W. , Narayanan S. , Sopori B. , Ravindra N. M. 
Published: April 2011

ABSTRACTExperimental studies of the room temperature emissivity of polysilicon are reported here. These measurements have been performed using a spectral emissometer operating in the wavelength range of 0.8 – 20 μm. The measured optical properties are deconvolved to yield the wavelength dependent refractive indices and extinction coefficient of polysilicon. An in house developed computer program, OPCalc, is deployed to perform these calculations. Experimental results of the temperature dependent emissivity of a-Si / SiO2 / Si / SiO2 / a-Si, fabricated on single side polished silicon substrates, in the temperature range of 300 to 1100 K have been reported here. These measurements are performed for a-Si thickness of 2100A. Comparisons of the temperature dependent radiative properties of these structures between the front and the back show that the contribution of surface roughness to emissivity is negligible- The exposure of these a-Si coated structures to high temperatures in open environment has caused these surfaces to oxidize. Interpretations, have been sought by comparisons of the experimental data with those on SiO2 / Si structures.
The Driving Pulse width Dependence of The Hysteresis Effect in ZnS:Mn Electroluminescent Devices: A Possible Addressing Method for Memory Tfel Displays
Authors: Fuh Andy Ying-Guey 
Published: April 2011

ABSTRACTA pronounced hysteresis effect was observed in the brightness versus pulse width response of memory electroluminescent (EL) devices driven near the threshold voltage. The use of this effect to address memory EL displays is suggested. A benefit of this technique is that the display is always operated near threshold with a relatively low dielectric stress. Longer device life might be therefore expected.
Development of High-Efficiency Zn2SiO4:Mn Thin Films for Flat Panel Cathodoluminescent Displays
Authors: Liu J. , Morton D. C. , Miller M. R. , Li Y. , Forsythe E. W. , Tompa G. S. 
Published: April 2011

ABSTRACTZn2SiO4:Mn thin films were deposited and studied as thin film phosphors for flat panel cathodoluminescent displays. Crystallized films with improved electrical conductivity were obtained after conventional and rapid thermal annealings in a N2 environment at 850Xy11100 °C for 0.25 to 60 minutes. A maximum cathodoluminescent efficiency of 1.3 Lm/W was achieved under dc excitation at 1500 volts. The luminescent emission from these thin films was peaked around 525 nm. The decay time of these films was controlled in the range of 2 to 10 ms by varying the deposition and annealing parameters. The fast response time of these thin films overcomes the long decay limitation of the Zn2SiO4:Mn powder phosphor in practical display applications.
Nanometer-Scale Investigation of Al-Based Alloy Films for Thin-Film Transistor Liquid Crystal Display Arrays
Authors: Takatsuji H. , Iiyori Hideo , Tsuji S. , Tsujimoto K. , Kuroda K. , Saka H. 
Published: April 2011

ABSTRACTAnnealing effects on Al-Nd (0.19 – 1.82 at. %) thin films deposited on a glass substrate have been investigated. It is found that the resistivity of an Al-Nd-alloy thin film decreases significantly after annealing at 300 °C or higher temperatures. Using cross-sectional transmission electron microscopy (X-TEM), we have observed segregation of Al-Nd inter-metallic precipitates and pure-Al grains during the annealing. The decrease of the resistivity can be attributed to the segregation. Segregation has been also detected from the increase of diffracted X-ray intensities corresponding to Al-Nd inter-metallic compounds in X-ray diffraction (XRD) analysis. Atomic force microscopy (AFM) observation has revealed that the optimum content ratio of Nd in Al-Nd alloys used as interconnect materials for thin-film-transistor liquid crystal display (TFT/LCD) applications is around 0.97 atomic %.
New Insights into The Transport and Field-Enhancement Effects in Sol-Gel Derived Colossal Magnetoresistive Thin Films
Authors: Krishnan Kannan M. , Ju H. L. , Sohn H.-C. , Nelson C. , Modak A. R. 
Published: April 2011

ABSTRACTThe transport mechanism underlying the colossal magnetoresistance (CMR) of doped manganites is not yet understood and their technological applications are limited by the high fields (∼IT) required to obtain any significant MR. Following the development of a polymeric chemical synthesis route, we have investigated the O2p unoccupied density of states in sol-gel derived Lal-xSrxMnO3 (0 < x < 0.7) thin films grown epitaxially on LaA1O3, by electron energy-loss spectroscopy at sub-eV resolution. The spectra show a distinct prepeak in the OK edge at the Fermi level, the intensity of which correlates directly with the conductivity of the film. Similar correlation was also obtained for La0.7Sr0.3MnO3-z annealed in vacuum to obtain well defined oxygen content (z) in the film. This confirms that the charge carriers in these manganese perovskites have significant oxygen 2p hole character and suggests that the “double exchange” mechanism has to be modified. In another set of experiments we have studied room-temperature field amplification effects to enhance the low-field sensitivity of La0.7Sr0.3MnO3-z films sandwiched between two thin rectangular slices of either α-Fe or Mn-Zn ferrite. This field amplification leads to an enhanced low-field MR value as high as 6% at an external field of 500 Oe which is 6 times the value observed without the amplification.
Epitaxial Ferroelectric Aurivillius-Type Phases on Metallic Oxides by Pulsed Laser Deposition
Authors: Curran C. , Senz St. , Pignolet A. , Alexe M. , Welke S. , Hesse D. 
Published: April 2011

ABSTRACTBi-based layered perovskites, also called Aurivillius-type phases, are superior to simple perovskite materials with regard to their ferroelectric long-term stability. Another way to alleviate fatigue and aging problems in metal-ferroelectric-metal (MFM) heterostructures is to replace the bottom metallic electrode with a conductive oxide electrode. An attempt to combine the two approaches has been made to investigate whether a further improvement in stability can be achieved. To promote an oriented growth of the ferroelectric films, epitaxial buffer layers (YSZ, Ce02) and epitaxial electrodes of (La0.5Sr0.5 )Co03 (LSC) have been consecutively deposited onto Si (100). Finally a ferroelectric thin film of the layered perovskite Bi4Ti3012 (BiT) has been grown. Rocking curve measurements demonstrate good epitaxial growth of both the buffer and the electrode layers. The ferroelectric thin films show a preferred c-axis orientation. Cross-section TEM images reveal a twinned superstructure in the LSC layer with a tripling of the lattice parameter. EDX line-scans show that a Co-enriched and Bi-depleted layer had formed at the BiT/LSC interface. After deposition of Au electrodes on both the BiT and the LSC layer, a hysteretic behavior could be detected and the ferroelectric properties of the c-oriented BiT film be confirmed.
Interplay Between Electronic Transport and Magnetic Order in Ferromagnetic Manganite Thin Films
Authors: Hundley M. R. , Neumeier J. J. , Heffher R. H. , Jia Q. X. , Wu X. D. , Thompson J. D. 
Published: April 2011

ABSTRACTThe transition metal oxides La1-xAxMnO3 (A = Ba, Ca, or Sr) order ferromagnetically with Curie temperatures ranging from as low as 50 K to well above room temperature. Magnetic order in these compounds results in a concomitant metal-insulator transition. The feature displayed by the manganites that is most important technologically is the extremely large negative magnetoresistance that achieves its largest values near the magnetic ordering temperature. Qualitatively, this colossal magnetoresistance (CMR) phenomenon involves the suppression of the relatively sharp maximum in the resistivity that is centered at Tc. When considered collectively, the anomalous temperature-dependent transport properties, the CMR effect, and the magnetically ordered ground state indicate that a novel interplay between magnetism and electronic transport occurs in the manganites. General features of the magnetic-field and temperature-dependent electrical resistivity and magnetization as displayed by PLD-grown thin films are examined. Particular emphasis is placed on what these measurements tell us about the conduction process both above and below the magnetic ordering temperature.
Electronic Doping in Epitaxial Pb(Zr0>52Ti0.48)03/SrRuO3 Heterostructures using a Ferroelectric Field Effect
Authors: Ahn C. H. , Tybell T. , Antognazza L. , Char K. , Beasley M. R. , Fischer O. , Triscone J.-M. 
Published: April 2011

ABSTRACTWe report on ferroelectric field effect experiments in ultrathin layers of the metallic perovskite SrRuC<3 using Pb(Zr0.52Ti0.48)O3/SrRuO3 epitaxial heterostructures. Switching the ferroelectric polarization of the Pb(Zr0.52Ti0.48)O3 layer induces a ∼ 10% change in the sheet resistance of the SrRuO3 layer that is nonvolatile and also reversible. Hall effect measurements that take into account the anomalous Hall effect reveal a carrier concentration of n ∼ 2 × 1022 electrons/cm3 and allow us to understand quantitatively the sign and magnitude of the observed resistance change. Of key importance for these experiments is the crystalline and surface quality of the SrRuO3 and Pb(Zr0.52Ti0.48)O3 layers. We also discuss how this general approach of nonvolatile doping using ferroelectrics opens new possibilities of directly creating small electronic structures without using traditional lithographic techniques.
AFM Observations on the Growth Mechanisms of Epitaxial Perovskite Oxide SrRuO3 Thin Films
Authors: Rao R. A. , Gan Q. , Eom C. B. 
Published: April 2011

ABSTRACTThe growth mechanism and surface morphology of epitaxial SrRuO3 thin films deposited on exact and vicinal (001) SrTiO3 and exact (001) LaAlO3 substrates has been studied. Vicinal substrates with miscut angle, a, up to 4° toward [010] direction were used. Atomic force microscope images show that the films grown on exact (001) SrTiO3 substrate had a growth mechanism involving two dimensional nucleation. In contrast, characteristic step patterns were observed on the films deposited on vicinal substrates, suggesting that these films had a step flow growth mode. The films deposited on exact (001) LaAlO3 substrates had a three dimensional island growth, due to the incoherence between the film and substrate lattice. These results were found to be consistent with the results of x-ray diffraction analysis of the in-plane domain structure.
Atomic Scale Engineering of SrTiO3 Single Crystal Surfaces and Bicrystal Boundaries for Epitaxial Growth of Oxide Thin Films
Authors: Jiang Q. D. , Zegenhagen J. 
Published: April 2011

ABSTRACTWe introduce a new annealing procedure to prepare well defined surfaces of SrTiO3 single crystal and bicrystal substrates. Annealing SrTiO3 (001) substrates in oxygen and then in ultra high vacuum produces a uniformly TiO2-terminated, atomically flat and ordered SrTiO3 (001) surfaces, as revealed by Auger electron spectroscopy, low energy electron diffraction, and high resolution scanning tunneling microscopy. Applying this annealing procedure to slightly off-cut (∼1.2°) SrTiO3 (001) surfaces has a strong influence on the resulting step structure. Particular annealing procedures can be used to tailor the structure and morphology of the surface and of bicrystal boundaries down to the atomic level. For example, steps of SrTiO3 (001) surfaces can be adjusted to a height of one, two, or multiple times the unit-cell size of STO (aSTO=0.3905 nm). Atomically flat SrTiO3 (001) substrates were used for deposition of SmBa2Cu3O7-δ (SBCO) thin films. The thickness (in a range from 10 nm to 200 nm) dependency of the surface morphology of SmBa2Cu3O7-δ films was investigated with UHV-STM. No spiral growth was observed. Surfaces of all films exhibit stacks of flat terraces which are frequently separated by steps, smaller than the c-axis length cSBCO of SBCO (cSBCO=1.17 nm).
Structural Characterization Of SrBi2Ta209 Thin Films
Authors: Ching-Prado E. , Pérez W. , Reynés-figueroa A. , Katiyar R. S. , Ravichandran D. , Bhalla A. S. 
Published: April 2011

ABSTRACTThin films of SrBiTa2O9, (SBT) were deposited on Si using Sol-Gel technique. The thicknesses of the films are 200 nm (A) and 400 nm (B), respectively. SEM studies show isolated grains in both SBT films with a grain size distribution between 0.1 and 0.5 μ. However, most of the grain size in the film is smaller than 0.1 μ. EDX analysis indicates that the films are inhomogeneous. FTIR external reflectivity measurements of the samples show bands around 1260, 936(for SBT2), 955(for SBT4), 770, 600 cm−1. Micro Raman spectra shows inhomogeneities in the SBT films. Bands corresponding to the SBT materials were found, but frequency shifts and broadening were observed in almost every band. Particularly, the band around 818 cm−1 was found to change from 785 to 827 cm−1. Also, due to the stretching of the Ta06 octahedron, the Alg mode was found to be approximately 163 cm−1. This change seems to be related to the Ta-0 bond length.
Chemical Solution Deposited BaTi03 AND SrTi03 Thin Films With Columnar Microstructure
Authors: Hoffmann S. , Hasenkox U. , Waser R. , Jia C. L. , Urban K. 
Published: April 2011

ABSTRACTWe show that CSD processing can be optimized in order to achieve columnar structured BaTiO3 and SrTiO3 thin films at elevated temperatures. In addition to these, columnar grain growth was also obtained for films of the solid solution (Ba0.7Sr0.3)TiO3 By controlling the film formation process, polycrystalline and columnar grained thin films were grown on Pt coated Si substrates at temperatures between 750° and 800°. The films were analyzed by glancing incidence X-ray diffraction and scanning electron microscopy. Detailed analysis on the thin films’ microstructure was performed by means of transmission electron microscopy. Based on these data, the film formation process is discussed with respect to process control and precursor chemistry. Differences in the crystallization process of BaTiO3 thin films compared to SrTiO3 films are pointed out.
The Development and Characterization of Crystallographic Texture in thin films for Magnetic Recording
Authors: Laughlin David E. , Tang Li , Lee Li-Lien , Hsu Yu-Nu , Lambeth David 
Published: April 2011

ABSTRACTThe development of crystallographic texture in thin film longitudinal recording media is discussed. Polycrystalline thin films may obtain their crystallographic texture by means of a nucleation process such as epitaxial nucleation on a polycrystalline underlayer or by means of a process involving a preferred growth direction. In this paper we will discuss various epitaxial nucleation textures that are obtained in media produced for magnetic recording. We will discuss the way that the underlayer controls the crystallographic texture of the magnetic layer, as well as methods used to control the texture of the underlayer itself. We give a brief overview of some of our recent findings in the growth of NiAl and FeAl films used for underlayers. Finally we will briefly discuss what we have called the tilted electron beam technique. In this technique selected area electron diffraction patterns are obtained at different angles of tilt and the development of arcs in the patterns is analyzed so as to determine the type and amount of crystallographic texture which is present in the films.
Magnetic Anisotropy and Growth Texture in Co35Pd65 Films
Authors: Jen S. U. , Huang J. Y. , Huang K. B. 
Published: April 2011

ABSTRACTPd-rich Co-Pd alloy films are well known to exhibit perpendicular anisotropy. In this study, Co35Pd65 films were made by the vapor deposition method. The thickness of the films ranged from 80 to 2000 Å. Following measurements were carried out on each film sample: the impurities and alloy compositions were checked by Auger depth profile analysis (AES), the surface topology was mapped out by an atomic force microscope (AFM), the structural analysis was done by using the X-ray diffractometer (XRD), and the magnetic properties, such as magnetic anisotropy and saturation magnetization, were measured by a SQUID magnetometer and/or a MOKE (using the longitudinal or polar effect) apparatus. Magnetic quantities, such as the out-of-plane (either hard or easy axis) squareness ratio Mr/Ms, saturation magnetization Ms, and anisotropy energy Ku, are closely related to the structural properties, such as the degree of (111) texture, grain size D, mode of growth (nucleation texture or growth texture), and impurities in films. The emphasis is placed on the thickness dependence of these quantities, and the interrelationship among them.
Magneto-Optical Effects of Ultrathin Ferro-, Antiferro- and Non-Magnetic Films
Authors: Suzuki Y. , Katayama T. , Geerts W. , .Grünberg P , Takanashi K. , Schreiber R. , Bruno P. , Yuasa S. 
Published: April 2011

AbstractThickness dependence of the magneto-optical Kerr effects (MOKE) in ultrathin ferromagnetic films, antiferromagnetic films and nonmagnetic films were measured carefully employing wedge shaped samples at room temperature. The oscillations of the polar Kerr ellipticiry with respect to the film thickness and its energy dependence were observed for the Fe and Au ultrathin films, and revealed a formation of spin-polarized quantum well states both in the bcc-Fe (100) layers and the fcc-Au(001) layers.On the other hand, bcc-Cr (100) ultrathin layers grown on 3ML of Fe(100) layer showed about 2ML period oscillation of the polar MOKE for the photon energy in between 2.25 and 3.75eV, indicating an existence of a long range antiferromagnetic order. The Cr film also showed energy dependent oscillation peaks for the very thin region (d<10ML). The longitudinal MOKE were measured also for Cr samples, and revealed 2ML period oscillation. The mechanism of the MOKE oscillations is discussed from the view points of quantum size effects and the antiferromagnetic order.
Morphology and Curie Temperature Changes upon Annealing of Co/W(110)
Authors: Bauer A. , Mühlig A. , Günther T. , Farle M. , Baberschke K. , Kaindl G. 
Published: April 2011

ABSTRACTAnnealing of CoAV(110) ultrathin films causes rather strong changes of film morphology and magnetic properties, which has been studied by scanning tunneling microscopy (STM) and alternating-current magneto-optical Kerr effect (ac-MOKE). Annealing above 500 K of room-temperature grown 2 monolayers (ML) thick Co/W(110) films leads to the formation of islands and a decrease of the Curie temperature 7C. At 4 ML, on the other hand, a network of interconnected islands is formed upon annealing, resulting in an enhanced TC. While the increase of TC at 4 ML is explained by an increase of the local film thickness, the anomalous TC behavior at 2 ML is assigned to the occurrence of superparamagnetism.
Magnetic X-Ray Resonant Scattering from a Dysprosium Epitaxial Film
Authors: Dumesnil K. , Stunault A. , Mangin Ph. , Vettier C. , Wermeille D. , Bernhoeft N. , Langridge S. , Dufour C. , Archal G. M. 
Published: April 2011

ABSTRACTMagnetic X-Ray resonant scattering performed at the Dysprosium Lni absorption edge permits to study the magnetic behaviour of a 3000 Å thick Dy film. The development of an helical magnetic order gives rise to intense magnetic resonant harmonics. The energy dependence of the resonant intensity has been investigated and presents a double resonance at the second harmonic measured in the σ-π geometry. The accurate thermal variation of the turn angle and of the c-parameter is given. These evolutions reveal the stabilisation of the helical phase in the Dysprosium film compared to the bulk case.