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Title: Differences between direct current and alternating current capacitance nonlinearities in high-k dielectrics and their relation to hopping conduction

Capacitance nonlinearities were studied in atomic layer deposited HfO{sub 2} films using two types of signals: a pure ac voltage of large magnitude (ac nonlinearities) and a small ac voltage superimposed to a large dc voltage (dc nonlinearities). In theory, ac and dc nonlinearities should be of the same order of magnitude. However, in practice, ac nonlinearities are found to be an order of magnitude higher than dc nonlinearities. Besides capacitance nonlinearities, hopping conduction is studied using low-frequency impedance measurements and is discussed through the correlated barrier hopping model. The link between hopping and nonlinearity is established. The ac nonlinearities are ascribed to the polarization of isolated defect pairs, while dc nonlinearities are attributed to electrode polarization which originates from defect percolation paths. Both the ac and dc capacitance nonlinearities display an exponential variation with voltage, which results from field-induced lowering of the hopping barrier energy.
Authors:
;  [1] ;  [2] ; ; ;  [1] ;  [3] ;  [4] ;  [3] ;  [5]
  1. Univ. Grenoble Alpes, LTM, F-38000 Grenoble (France)
  2. (Tunisia)
  3. (France)
  4. Univ. Grenoble Alpes, G2ELAB, F-38000 Grenoble (France)
  5. El Manar University, LMOP, 2092 Tunis (Tunisia)
Publication Date:
OSTI Identifier:
22314682
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 8; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALTERNATING CURRENT; CAPACITANCE; DEPOSITION; DIELECTRIC MATERIALS; DIRECT CURRENT; ELECTRIC POTENTIAL; ELECTRODES; FILMS; HAFNIUM OXIDES; IMPEDANCE; LAYERS; NONLINEAR PROBLEMS; POLARIZATION; SIGNALS