Dielectric breakdown in epitaxial BaTiO3 thin films

In this work, thin epitaxial layers of dielectric barium titanate (BaTiO3 or BTO) were grown on Nb-doped strontium titanate (001) substrates using either molecular beam epitaxy or atomic layer deposition and then electrically stressed to the point of breakdown. The BTO layer thicknesses were in the...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Journal of vacuum science and technology. B, Nanotechnology & microelectronics Nanotechnology & microelectronics, 2020-07, Vol.38 (4), Article 044007
Hauptverfasser: Wu, HsinWei, Ponath, Patrick, Lin, Edward L., Wallace, Robert M., Young, Chadwin, Ekerdt, John G., Demkov, Alexander A., McCartney, Martha R., Smith, David J.
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:In this work, thin epitaxial layers of dielectric barium titanate (BaTiO3 or BTO) were grown on Nb-doped strontium titanate (001) substrates using either molecular beam epitaxy or atomic layer deposition and then electrically stressed to the point of breakdown. The BTO layer thicknesses were in the range of 20–60 nm, and typical breakdown fields were in the range of 1.5–3.0 MV/cm. Electron microscopy and electron energy-loss spectroscopy (EELS) were used to provide information about the degradation mechanism. High-resolution imaging revealed widespread structural damage in the BTO films after breakdown had occurred, with substantial polycrystallinity as well as amorphous regions. EELS analysis of the stressed films showed characteristic signatures of valence change in the Ti L23 EELS spectra associated with the accumulation of oxygen vacancies. Stressed heterostructures that had been patterned by electron lithography showed similar trends, including degraded crystallinity as well as oxygen loss.
ISSN:2166-2746
2166-2754
DOI:10.1116/6.0000237