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Role and Optimization of the Active Oxide Layer in TiO 2 ‐Based RRAM
Author(s) -
Regoutz Anna,
Gupta Isha,
Serb Alexantrou,
Khiat Ali,
Borgatti Francesco,
Lee TienLin,
Schlueter Christoph,
Torelli Piero,
Gobaut Benoit,
Light Mark,
Carta Daniela,
Pearce Stuart,
Panaccione Giancarlo,
Prodromakis Themistoklis
Publication year - 2016
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201503522
Subject(s) - materials science , annealing (glass) , thin film , resistive random access memory , x ray photoelectron spectroscopy , optoelectronics , photoemission spectroscopy , active layer , oxide , nanotechnology , electrode , analytical chemistry (journal) , layer (electronics) , chemical engineering , composite material , chemistry , engineering , metallurgy , thin film transistor , chromatography
TiO 2 is commonly used as the active switching layer in resistive random access memory. The electrical characteristics of these devices are directly related to the fundamental conditions inside the TiO 2 layer and at the interfaces between it and the surrounding electrodes. However, it is complex to disentangle the effects of film “bulk” properties and interface phenomena. The present work uses hard X‐ray photoemission spectroscopy (HAXPES) at different excitation energies to distinguish between these regimes. Changes are found to affect the entire thin film, but the most dramatic effects are confined to an interface. These changes are connected to oxygen ions moving and redistributing within the film. Based on the HAXPES results, post‐deposition annealing of the TiO 2 thin film was investigated as an optimisation pathway in order to reach an ideal compromise between device resistivity and lifetime. The structural and chemical changes upon annealing are investigated using X‐ray absorption spectroscopy and are further supported by a range of bulk and surface sensitive characterisation methods. In summary, it is shown that the management of oxygen content and interface quality is intrinsically important to device behavior and that careful annealing procedures are a powerful device optimisation technique.