Chemical controllability of charge states of nitrogen-related defects in HfOx Ny: First-principles calculations

N. Umezawa, K. Shiraishi, Y. Akasaka, A. Oshiyama, S. Inumiya, S. Miyazaki, K. Ohmori, Toyohiro Chikyo, T. Ohno, K. Yamabe, Y. Nara, K. Yamada

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Relative stabilities of nitrogen-related defects in HfOx Ny have been extensively studied in terms of formation energies by using first-principles calculations. We have found that the two oxygen vacancies coupled with two substitutional nitrogen atoms at oxygen sites is the predominant defect in a low oxygen chemical potential (μO) with doubly positive [(NO) 2 (VO) 2] +2 and neutral [(NO) 2 (VO) 2] 0 forms for the p -type and n -type silicon substrates, respectively. On the other hand, the negatively charged substitutional nitrogen [(NO) 2] -2 predominates in a higher μO condition. A neutral defect, [(NO) 2 VO] 0, is found to be stabilized in the midregion of μO, which indicates that the oxygen partial pressure is an important factor to control fixed charges that cause malfunction in HfOx Ny -based devices. An electron counting concept is shown to be valid to predict the stable forms of the defects.

Original languageEnglish
Article number165130
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume77
Issue number16
DOIs
Publication statusPublished - 2008 Apr 25
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Chemical controllability of charge states of nitrogen-related defects in HfOx Ny: First-principles calculations'. Together they form a unique fingerprint.

  • Cite this

    Umezawa, N., Shiraishi, K., Akasaka, Y., Oshiyama, A., Inumiya, S., Miyazaki, S., Ohmori, K., Chikyo, T., Ohno, T., Yamabe, K., Nara, Y., & Yamada, K. (2008). Chemical controllability of charge states of nitrogen-related defects in HfOx Ny: First-principles calculations. Physical Review B - Condensed Matter and Materials Physics, 77(16), [165130]. https://doi.org/10.1103/PhysRevB.77.165130