Dielectric properties and electronic transitions of porous and nanostructured cerium oxide films
Φόρτωση...
Ημερομηνία
Συγγραφείς
Logothetidis, S.
Patsalas, P.
Evangelou, E. K.
Konofaos, N.
Tsiaoussis, I.
Frangis, N.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Elsevier
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Materials Science and Engineering B-Solid State Materials for Advanced Technology
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
Cerium dioxide (CeO2) exhibits exceptional electronic properties such as optical transparency and high refractive index (n) and high dc dielectric constant (k). Therefore, it is an attractive material for ultra-thin gate oxide in CMOS technology, where high-k dielectrics are required. We study the electronic properties of nanostructured and porous cerium oxide (CeOx) films, 110-500 nm thick, grown on Si by electron beam evaporation (EBE) and ion beam assisted deposition (IBAD). The film microstructure and morphology (grain size, porosity, defect concentration, surface and interface roughness) are controlled by varying the process parameters appropriately. They have been studied by high-resolution and transmission electron microscopy (HRTEM). The optical properties have been studied by spectroscopic ellipsometry (SE) and k was determined by capacitance measurements. We have found that the values of k and n (1.6-2.5 depending on porosity) are affected by the electronic transitions, which are strongly correlated with the microstructure and morphology of the films. We investigate how the microstructure and morphology variations affect the absolute values of the dc dielectric constant and of the dielectric function at the UV-Vis and IR spectral regions. In addition, we investigate the very important role of the defects, which have the form of grain boundaries, trivalent Ce3+ and O vacancies. As a result we were able to tailor n and k of CeOx films controlling their porosity and defect density. (C) 2003 Elsevier B.V. All rights reserved.
Περιγραφή
Λέξεις-κλειδιά
dielectric properties, electronic transitions, cerium oxide films, pulsed-laser deposition, ceo2 thin-films, optical-properties, epitaxial-growth, silicon, si(111), layers, temperature
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000221657000016
http://ac.els-cdn.com/S0921510703005452/1-s2.0-S0921510703005452-main.pdf?_tid=46a40f87f1025c24ca1fc0d50d56470b&acdnat=1339755796_ee7fc322193f30ba1f5664c0502fef0d
http://ac.els-cdn.com/S0921510703005452/1-s2.0-S0921510703005452-main.pdf?_tid=46a40f87f1025c24ca1fc0d50d56470b&acdnat=1339755796_ee7fc322193f30ba1f5664c0502fef0d
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Μηχανικών Επιστήμης Υλικών