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P.056 Combined conventional and amplitude-integrated EEG monitoring in neonates: a prospective study
- SG Buttle, B Lemyre, E Sell, S Redpath, S Bulusu, R Webster, D Pohl
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- Canadian Journal of Neurological Sciences / Volume 46 / Issue s1 / June 2019
- Published online by Cambridge University Press:
- 05 June 2019, p. S29
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Background: Seizure monitoring via amplitude-integrated EEG (aEEG) is standard of care in many NICUs; however, conventional EEG (cEEG) is the gold standard for seizure detection. We compared the diagnostic yield of aEEG interpreted at the bedside, aEEG interpreted by an expert, and cEEG. Methods: Neonates received aEEG and cEEG in parallel. Clinical events and aEEG were interpreted at bedside and subsequently independently analyzed by experienced neonatology and neurology readers. Sensitivity and specificity of bedside aEEG as compared to expert aEEG interpretation and cEEG were evaluated. Results: Thirteen neonates were monitored for an average duration of 33 hours (range 15-94). Fourteen seizure-like events were detected by clinical observation, and 12 others by bedside aEEG analysis. None of the bedside aEEG events were confirmed as seizures on cEEG. Expert aEEG interpretation had a sensitivity of 13% with 46% specificity for individual seizure detection (not adjusting for patient differences), and a sensitivity of 50% with 46% specificity for detecting patients with seizures. Conclusions: Real-world bedside aEEG monitoring failed to detect seizures evidenced via cEEG, while misclassifying other events as seizures. Even post-hoc expert aEEG interpretation provided limited sensitivity and specificity. Considering the poor sensitivity and specificity of bedside aEEG interpretation, combined monitoring may provide limited clinical benefit.
P.130 Canadian physician attitudes towards long term EEG monitoring in the neonatal intensive care unit
- SG Buttle, E Sell, B Lemyre, D Pohl
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- Journal:
- Canadian Journal of Neurological Sciences / Volume 45 / Issue s2 / June 2018
- Published online by Cambridge University Press:
- 27 June 2018, p. S50
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Background: Long-term EEG monitoring (LTEM), including amplitude-integrated (aEEG) or conventional EEG (cEEG), is increasingly being used in critically ill neonates. Despite an abundance of studies regarding the clinical utility of LTEM, much is unknown regarding provider attitudes toward this tool. We aimed to evaluate neurologist and neonatologist opinions regarding LTEM in the NICU and describe current Canadian practices. Methods: A 15-item questionnaire was developed with input from neonatologists and pediatric neurologists at two Canadian centres. The questionnaire was piloted at our hospital and subsequently distributed to Canadian neonatologists and pediatric neurologists. Results: All 16 local respondents use LTEM in the NICU. Neonatologists were more likely to combine aEEG and cEEG, and monitor for longer durations than pediatric neurologists. However, most pediatric neurologists would like to monitor more (71%), compared to neonatologists who were more likely to say that current monitoring practices are sufficient. High rates of neonatologists (88%) and neurologists (85%) are interested in attending an education session on LTEM. Conclusions: Preliminary data suggests neonatologists and pediatric neurologists differ in their approach to LTEM. Results from our national questionnaire will be analyzed shortly, and may inform the development of educational materials as well as future studies that involve multi-centre efforts.
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- By Rose Teteki Abbey, K. C. Abraham, David Tuesday Adamo, LeRoy H. Aden, Efrain Agosto, Victor Aguilan, Gillian T. W. Ahlgren, Charanjit Kaur AjitSingh, Dorothy B E A Akoto, Giuseppe Alberigo, Daniel E. Albrecht, Ruth Albrecht, Daniel O. Aleshire, Urs Altermatt, Anand Amaladass, Michael Amaladoss, James N. Amanze, Lesley G. Anderson, Thomas C. Anderson, Victor Anderson, Hope S. Antone, María Pilar Aquino, Paula Arai, Victorio Araya Guillén, S. Wesley Ariarajah, Ellen T. Armour, Brett Gregory Armstrong, Atsuhiro Asano, Naim Stifan Ateek, Mahmoud Ayoub, John Alembillah Azumah, Mercedes L. García Bachmann, Irena Backus, J. Wayne Baker, Mieke Bal, Lewis V. Baldwin, William Barbieri, António Barbosa da Silva, David Basinger, Bolaji Olukemi Bateye, Oswald Bayer, Daniel H. Bays, Rosalie Beck, Nancy Elizabeth Bedford, Guy-Thomas Bedouelle, Chorbishop Seely Beggiani, Wolfgang Behringer, Christopher M. Bellitto, Byard Bennett, Harold V. Bennett, Teresa Berger, Miguel A. Bernad, Henley Bernard, Alan E. Bernstein, Jon L. Berquist, Johannes Beutler, Ana María Bidegain, Matthew P. Binkewicz, Jennifer Bird, Joseph Blenkinsopp, Dmytro Bondarenko, Paulo Bonfatti, Riet en Pim Bons-Storm, Jessica A. Boon, Marcus J. Borg, Mark Bosco, Peter C. Bouteneff, François Bovon, William D. Bowman, Paul S. Boyer, David Brakke, Richard E. Brantley, Marcus Braybrooke, Ian Breward, Ênio José da Costa Brito, Jewel Spears Brooker, Johannes Brosseder, Nicholas Canfield Read Brown, Robert F. Brown, Pamela K. Brubaker, Walter Brueggemann, Bishop Colin O. Buchanan, Stanley M. Burgess, Amy Nelson Burnett, J. Patout Burns, David B. Burrell, David Buttrick, James P. Byrd, Lavinia Byrne, Gerado Caetano, Marcos Caldas, Alkiviadis Calivas, William J. Callahan, Salvatore Calomino, Euan K. Cameron, William S. Campbell, Marcelo Ayres Camurça, Daniel F. Caner, Paul E. Capetz, Carlos F. Cardoza-Orlandi, Patrick W. Carey, Barbara Carvill, Hal Cauthron, Subhadra Mitra Channa, Mark D. Chapman, James H. Charlesworth, Kenneth R. Chase, Chen Zemin, Luciano Chianeque, Philip Chia Phin Yin, Francisca H. Chimhanda, Daniel Chiquete, John T. Chirban, Soobin Choi, Robert Choquette, Mita Choudhury, Gerald Christianson, John Chryssavgis, Sejong Chun, Esther Chung-Kim, Charles M. A. Clark, Elizabeth A. Clark, Sathianathan Clarke, Fred Cloud, John B. Cobb, W. Owen Cole, John A Coleman, John J. Collins, Sylvia Collins-Mayo, Paul K. Conkin, Beth A. Conklin, Sean Connolly, Demetrios J. Constantelos, Michael A. Conway, Paula M. Cooey, Austin Cooper, Michael L. Cooper-White, Pamela Cooper-White, L. William Countryman, Sérgio Coutinho, Pamela Couture, Shannon Craigo-Snell, James L. Crenshaw, David Crowner, Humberto Horacio Cucchetti, Lawrence S. Cunningham, Elizabeth Mason Currier, Emmanuel Cutrone, Mary L. Daniel, David D. Daniels, Robert Darden, Rolf Darge, Isaiah Dau, Jeffry C. Davis, Jane Dawson, Valentin Dedji, John W. de Gruchy, Paul DeHart, Wendy J. Deichmann Edwards, Miguel A. De La Torre, George E. Demacopoulos, Thomas de Mayo, Leah DeVun, Beatriz de Vasconcellos Dias, Dennis C. Dickerson, John M. Dillon, Luis Miguel Donatello, Igor Dorfmann-Lazarev, Susanna Drake, Jonathan A. Draper, N. Dreher Martin, Otto Dreydoppel, Angelyn Dries, A. J. Droge, Francis X. D'Sa, Marilyn Dunn, Nicole Wilkinson Duran, Rifaat Ebied, Mark J. Edwards, William H. Edwards, Leonard H. Ehrlich, Nancy L. Eiesland, Martin Elbel, J. Harold Ellens, Stephen Ellingson, Marvin M. Ellison, Robert Ellsberg, Jean Bethke Elshtain, Eldon Jay Epp, Peter C. Erb, Tassilo Erhardt, Maria Erling, Noel Leo Erskine, Gillian R. Evans, Virginia Fabella, Michael A. Fahey, Edward Farley, Margaret A. Farley, Wendy Farley, Robert Fastiggi, Seena Fazel, Duncan S. Ferguson, Helwar Figueroa, Paul Corby Finney, Kyriaki Karidoyanes FitzGerald, Thomas E. FitzGerald, John R. Fitzmier, Marie Therese Flanagan, Sabina Flanagan, Claude Flipo, Ronald B. Flowers, Carole Fontaine, David Ford, Mary Ford, Stephanie A. Ford, Jim Forest, William Franke, Robert M. Franklin, Ruth Franzén, Edward H. Friedman, Samuel Frouisou, Lorelei F. Fuchs, Jojo M. Fung, Inger Furseth, Richard R. Gaillardetz, Brandon Gallaher, China Galland, Mark Galli, Ismael García, Tharscisse Gatwa, Jean-Marie Gaudeul, Luis María Gavilanes del Castillo, Pavel L. Gavrilyuk, Volney P. Gay, Metropolitan Athanasios Geevargis, Kondothra M. George, Mary Gerhart, Simon Gikandi, Maurice Gilbert, Michael J. Gillgannon, Verónica Giménez Beliveau, Terryl Givens, Beth Glazier-McDonald, Philip Gleason, Menghun Goh, Brian Golding, Bishop Hilario M. Gomez, Michelle A. Gonzalez, Donald K. Gorrell, Roy Gottfried, Tamara Grdzelidze, Joel B. Green, Niels Henrik Gregersen, Cristina Grenholm, Herbert Griffiths, Eric W. Gritsch, Erich S. Gruen, Christoffer H. Grundmann, Paul H. Gundani, Jon P. Gunnemann, Petre Guran, Vidar L. Haanes, Jeremiah M. 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Yee, Viktor Yelensky, Yeo Khiok-Khng, Gustav K. K. Yeung, Angela Yiu, Amos Yong, Yong Ting Jin, You Bin, Youhanna Nessim Youssef, Eliana Yunes, Robert Michael Zaller, Valarie H. Ziegler, Barbara Brown Zikmund, Joyce Ann Zimmerman, Aurora Zlotnik, Zhuo Xinping
- Edited by Daniel Patte, Vanderbilt University, Tennessee
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- The Cambridge Dictionary of Christianity
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- 05 August 2012
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- 20 September 2010, pp xi-xliv
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Experimental Study on the Role of Hydrogen in the Breakdown of Low-Temperature Si Epitaxy
- J. Platen-Schwarzkopf, W. Bohne, W. Fuhs, K. Lips, J. Röhrich, B. Selle, I. Sieber
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- Journal:
- MRS Online Proceedings Library Archive / Volume 686 / 2001
- Published online by Cambridge University Press:
- 15 March 2011, A3.1
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- 2001
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Homoepitaxial Si layers were grown on Si(100) at temperatures of 325 - 500 °C by Electron-Cyclotron Resonance Plasma-Enhanced Chemical Vapor Deposition (ECR PECVD) from a gas mixture of SiH4,H2 and Ar. Ar was added in order to realize high growth rates where the breakdown of epitaxy was well observed. Si disorder depth profiles derived from RBS channeling spectra were compared with hydrogen depth distributions measured by Heavy-Ion Elastic Recoil Detection Analysis (HI-ERDA) and Secondary Ion Mass Spectroscopy (SIMS). The results suggest that the transition from epitaxial to amorphous growth proceeds through two stages: (1) a highly defective but still ordered growth with the defect density increasing as the growth proceeds and (2) the formation of conically shaped precipitates of amorphous Si. Both regions act as an increasingly effective sink for excessive hydrogen which diffuses from the growth surface into the bulk of the sample. In perfectly grown epitaxial films, where the overall concentration of excessive hydrogen was low, the hydrogen diffusion tail was found to extend far beyond the interface into the Si substrate.
Ion-assisted Sputter Deposition of Microcrystalline Silicon Films with Pulsed-DC Plasma Excitation
- P. Reinig, F. Fenske, B. Selle, W. Fuhs
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- MRS Online Proceedings Library Archive / Volume 664 / 2001
- Published online by Cambridge University Press:
- 17 March 2011, A5.7
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- 2001
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We have applied a novel Ion-Assisted Sputter Deposition (IASD) method to deposit microcrystalline silicon (µc-Si) thin films with high deposition rates. An unbalanced magnetron sputter source together with an asymmetrical bipolar pulsed-DC plasma excitation operating in the frequency range 50-250 kHz was used for realizing high ion fluxes to the growing film. µc-Si films of high crystallinity are obtained at T > 400 °C with growth rates of up to 90 nm/min. The crystallinity of the films is characterized by the thickness-independent ratio of the optical thickness n·d determined by FTIR measurements and the atomic area density N·d as given by RBS analysis.
Composition and Structure of Epitaxial CaF2 Layers at the First Stages of Their Growth on Si(111)
- R. Würz, W. Bohne, W. Fuhs, J. Röhrich, M. Schmidt, A. Schöpke, B. Selle
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- MRS Online Proceedings Library Archive / Volume 696 / 2001
- Published online by Cambridge University Press:
- 17 March 2011, N3.21
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- 2001
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CaF2 films with thicknesses in the monolayer range (<20 Å) were grown on Si(111) by evaporation from a CaF2 source at UHV conditions. They were characterized ex-situ by Heavy-Ion Elastic Recoil Detection Analysis (HI-ERDA), RBS/Channeling, X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM). The F/Ca ratio of the films was found to depend on the growth temperature Ts and to deviate appreciably from the stoichiometric composition (F/Ca=2). Due to an interface reaction which leads to a CaF-interface layer a change from polycrystalline to epitaxial growth occurs at Ts=450°C. At higher temperature film growth started with a closed layer of CaF on top of which CaF2 layers with an increasing fraction of pinholes were formed. By means of a two-step process at different temperatures, the amount of pinholes could be strongly reduced. It was found, that buffer layers of CaF2 with a CaF interface layer introduced in Au/p-Si contacts enhance the barrier height by as much as 0.36eV to values of 0.64eV.
Crystalline Si Films Grown Epitaxially at Low Temperatures by ECR-PECVD
- J. Platen, B. Selle, S. Christiansen, M. Nerding, M. Schmidbauer, W. Fuhs
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- MRS Online Proceedings Library Archive / Volume 609 / 2000
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- 17 March 2011, A8.6
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- 2000
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Electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR-PECVD) is used to grow thin epitaxial films on Si(100) wafers. We report on systematic variations of deposition parameters like substrate temperature, substrate dc bias voltage, and gas composition. The structural quality was significantly improved by increasing the substrate temperature from 325 to 500 °C. Simultaneously, compressive lattice strain tends to increase. A negative dc bias voltage resulted in highly disordered films and increased surface roughness due to enhanced ion damage. In contrast positive bias voltages decreased the defect creation by reducing the ion bombardment of the surface during growth. Under so far optimized conditions the remaining disorder is given by two-dimensional, extended defects running parallel to the growth direction and forming grain boundaries with a lateral spacing of 500–700 nm. The single grains are essentially free of one- and two-dimensional defects and show the same orientation as the substrate. By reducing the H2 dilution and adding Ar to the excitation gas the deposition rate increased from 5.3 to 16.2 nm/min. This resulted in inferior structural quality which might be attributed to the reduced etching effect, the enhanced ion bombardment and/or the increased growth rate.
Solar-Cell Suitable μc-Si Films Grown by ECR-CVD
- M. Birkholz, E. Conrad, K. Lips, B. Selle, I. Sieber, S. Christiansen, W. Fuhs
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- MRS Online Proceedings Library Archive / Volume 609 / 2000
- Published online by Cambridge University Press:
- 17 March 2011, A5.5
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- 2000
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The preparation of μc-Si films from SiH4-H2 mixtures by electron-cyclotron resonance (ECR) CVD at deposition temperatures ≤ 400°C on foreign substrates is reported. Deposition conditions were identified for which Si films with a high degree of crystallinity were grown as was confirmed by Raman spectroscopy. A factorial analysis was carried out, for which the influence of deposition temperature, microwave power, hydrogen dilution and total pressure on film growth were investigated. Samples of optimized crystallinity were prepared in a lowpressure and high-hydrogen dilution regime. In-plane grain sizes were measured by TEM and found to be on the order of 10 - 12 nm. Next to the optimization of crystallinity several sources of impurity contamination during film deposition were identified and eliminated. Intrinsic μc-Si layers could be prepared under these conditions that exhibited a dark conductivity σd of 2 × 10-7 S/cm and photosensitivity σph/σd of 150. It is concluded that ECR CVD is capable of producing intrinsic layers with electronic properties as necessary for use in state-of-the-art n-i-p μc-Si solar cells.
Characterization of Microcrystalline Si Films by MeV Ion Scattering Techniques
- W. Bohne, J. Röhrich, B. Selle, M. Birkholz, F. Fenske, W. Fuhs, J. Platen-Schwarzkopf, P. Reinig
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- Journal:
- MRS Online Proceedings Library Archive / Volume 638 / 2000
- Published online by Cambridge University Press:
- 17 March 2011, F14.24.1
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- 2000
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Rutherford Backscattering Spectroscopy (RBS) and channeling studies with 1.4 MeV−4He ions as well as Heavy-Ion Elastic Recoil Detection Analysis (HI-ERDA) with 230 MeV 129Xe ions have been applied to characterize structural properties and the impurity content of thin Si films. The analytical potential of these ion-beam techniques is demonstrated for two types of samples: (1) μc-Si films prepared by dc magnetron sputtering in a pure Ar plasma and (2) homoepitaxial Si films deposited by low-temperature electron-cyclotron resonance PECVD at the transition from oriented to disordered growth. For μc-Si the atomic area density N.d obtained by RBS was compared with the optical thickness n.d (n=refractive index) derived from the interference structure of IR reflection spectra. It is shown that the ratio R=n.d/N.d of these quantities can serve as a figure of merit for the degree of crystalline order. An apparent similarity was found in the case of the epitaxially grown films between the Si disorder profiles evaluated from the RBS channeling spectra and the hydrogen and oxygen profiles determined by HI-ERDA. This suggests that hydrogen and oxygen are preferentially incorporated in the disordered parts of the films.
Homoepitaxial Growth of Si at Low Temperature (325 °C)
- J. Platen, B. Selle, I. Sieber, U. Zeimer, W. Fuhs
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- Journal:
- MRS Online Proceedings Library Archive / Volume 570 / 1999
- Published online by Cambridge University Press:
- 10 February 2011, 91
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- 1999
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Electron cyclotron resonance chemical vapor deposition (ECR-CVD) is used to grow to prepare epitaxial films on Si(100), Si(111), and Si(311) at 325 °C with a growth rate of 10…12 nm/min. On Si(100) up to a layer thickness of more than 300 nm the films exhibit a well defined and smooth interface and a perfectly ordered lattice structure. Beyond a critical thickness of about 500 nm the formation of conically shaped, amorphous regions was observed. At a thickness of 1.6 µm only 10… 15 % of the surface consists of these amorphous cones. On Si(311), Si(111), and Si(011) the critical epitaxial thicknesses hepi depends on the crystallographic orientation of the substrate in the sequence hepi(311) > hepi(111) > hepi(011) with an abrupt change of the film structure from crystalline to amorphous
ZnO/c-Si Heterojunction Interface Tuning by Interlayers
- F. Fenske, K. Kliefoth, L. Elstner, B. Selle
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- Journal:
- MRS Online Proceedings Library Archive / Volume 426 / 1996
- Published online by Cambridge University Press:
- 10 February 2011, 135
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- 1996
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The junction properties of isotype and anisotype n+-ZnO/c-Si heterostructures have been studied by electrical and photoelectrical methods. We present evidence that the junction properties are strongly affected by a 10–30 nm thick ZnO layer closest to the heterointerface with distinctively different properties than those of the ZnO film bulk. This layer supports a dominant current flow via multistep tunnelling-recombination. When a 10 nm thin ZnS or ZnSe interlayer is inserted charge transport is controlled by thermionic emission. The interlayer acts as spacer and increases the band bending in the silicon absorber. However, there is still a too high trap density at the interlayer/c-Si interface, so that Voc does not exceed 0.25–0.32 V.
Influence of Stoichiometric Variations and Rapid Thermal Processing of β-FESI2 thin Films on their Electrical and Microstructural Properties
- M. Döscher, B. Selle, M. Pauli, F. Kothe, J. Szymanski, J. Müller, H. Lange
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- Journal:
- MRS Online Proceedings Library Archive / Volume 402 / 1995
- Published online by Cambridge University Press:
- 15 February 2011, 325
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- 1995
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Amorphous irondisilicide thin films were deposited on silicon substrates in a RF sputtering process, followed by rapid thermal crystallization by means of moving the thin film beneath a line-shaped electron beam to form β-FeSi2. Depending on the deposition process parameters, films of a different stoichiometry can be produced. The deviations from the 1:2 stoichiometry, which have been determined by Rutherford Backscattering (RBS), are related to changes in the microstructure (studied by microscopic methods like TEM and AFM), the infrared phonon spectra (measured by FTIR spectroscopy) and the electrical properties of the crystallized films. The microstructure of the iron disilicide thin films is improved when the composition significantly deviates from 2.0, probably due to silicon interstitials in the silicide thin film. Films of different stoichiometry result in p- or n-type thin films with carrier densities below 5×1018cm−3 and hall mobilities up to 180cm 2/Vs. First results show that not only β-FeSi2-siliconheterojunctions as reported before but also pn-β-FeSi2-homojunctions show rectifying behavior. Rapid thermal processing with the line electron beam leads to a further improvement of the film quality when the scan velocity is increased up to the order of several cm/s.
Multilevel Contact System with a Thin Silicide Reaction Controlling Interlayer
- F. Fenske, S. Schulze, B. Selle, H. Lange, W. Wolke
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- Journal:
- MRS Online Proceedings Library Archive / Volume 320 / 1993
- Published online by Cambridge University Press:
- 03 September 2012, 427
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- 1993
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Taking advantage of controllable interdiffusion and reaction processes by using a 50 nm thin Ti interlayer an annealing step in the temperature range from 450 to 475°C transforms the TiNiAg layer sequence on silicon into a stable final state, whereby a contamination free, homogeneous nanoscale NiSi contact layer arises with low values of the contact resistance. Intercalating a thin Ti layer the nickel silicide growth rate is lowered by 2 orders of magnitude. Low sheet resistance and a good bondability are preserved by the remaining Ni-Ag top layer sequence which does not interact during the contact formation process.