High-resolution three-dimensional scanning transmission electron microscopy characterization of oxide-nitride-oxide layer interfaces in Si-based semiconductors using computed tomography

Shoji Sadayama, Hiromi Sekiguchi, Alexander Bright, Naohisa Suzuki, Kazuhiro Yamada, Kenji Kaneko

Research output: Contribution to journalArticle


Oxide-nitride-oxide (ONO) layer structures are widely used for charge storage in flash memory devices. The ONO layer interfaces should be as flat as possible, so measurement of the nanoscale roughness of those interfaces is needed. In this study, quantification of an ONO film from a commercially available flash memory device was carried out with a pillar-shaped specimen using scanning transmission electron microscopy (STEM) and computed tomography. The ONO area contained only low Z-and low STEM-contrast materials, which makes high-quality reconstruction difficult. The optimum three-dimensional reconstruction was achieved with an STEM annular dark-field detector inner collection angle of 32 mrad, a sample tilt range from-78° to +78° and 25 iterations for the simultaneous iterative reconstruction technique.

Original languageEnglish
Pages (from-to)243-251
Number of pages9
JournalJournal of Electron Microscopy
Issue number3
Publication statusPublished - Jun 1 2011


All Science Journal Classification (ASJC) codes

  • Instrumentation

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