Dielectric breakdown in epitaxial BaTiO3 thin films
Abstract
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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 01, 2020
- Source ID
- 10.1116/6.0000237
Entities
People
- Alexander A Demkov
- Chadwin D Young
- David J Smith
- Edward L. Lin
- Hsinwei Wu
- John G Ekerdt
- Martha R. Mccartney
- Patrick Ponath
- Robert M Wallace
Organizations
- Air Force Office of Scientific Research
- Arizona State University
- University of Texas at Austin
- University of Texas at Dallas