Metal-organic chemical vapor deposition of HfO2 by alternating supply of tetrakis-diethylamino-hafnium and remote-plasma oxygen

Sadayoshi Horii, Kazuhiko Yamamoto, Masayuki Asai, Hironobu Miya, Isao Kaneko, Toshinobu Ishihara, Shigenori Hayashi, Masaaki Niwa

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

HfO2 films were fabricated through an alternating supply process, which consisted of deposition using tetrakis-diethylaminohafnium (TDEAHf:Hf(N(C2H5)2)4), followed by oxidation using remote-plasma oxygen (RPO). Deposition rates were found to depend on temperature (above 350°C) and the supply duration of TDEAHf, which indicated a non-self-limiting growth mode. X-ray photoelectron spectroscopy (XPS) analysis revealed that as-deposited films fabricated by supplying only TDEAHf were unstable with the presence of carbon and nitrogen impurities, but these can be removed by supplying RPO. Sufficient supply durations of RPO produced stoichiometric HfO2 films accompanied by an efficient reduction in the leakage current of the films, but an excess RPO supply duration resulted in a larger equivalent oxide thickness (EOT) due to a decrease in the permittivity of the interfacial layer. By optimizing the supply durations of TDEAHf and RPO, a minimal EOT of 1.6 nm and a leakage current of 1 × 10-4 A/cm2 at -1 V relative to the flat-band voltage were achieved.

Original languageEnglish
Pages (from-to)6963-6967
Number of pages5
JournalJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
Volume43
Issue number10
DOIs
Publication statusPublished - 2004 Oct 1
Externally publishedYes

Keywords

  • Dielectric film
  • Hafnium oxide
  • MOCVD
  • Remote-plasma oxygen

ASJC Scopus subject areas

  • Engineering(all)
  • Physics and Astronomy(all)

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