Synthesis and structures of bis(2-dimethylaminoethyl)amine adducts of strontium bis(2,2,6,6-tetramethylheptane-3,5-dionate) and their use in the CVD of cubic strontium-doped hafnium dioxides

Bing Luo, Dan Yu, Benjamin E. Kucera, Stephen A. Campbell, Wayne L. Gladfelter

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

Monomeric, eight-coordinate Sr(tmhd)2[HN(CH2CH 2NMe2)2](EtOH) (1), where tmhd is 2,2,6,6-tetramethylheptane-3,5-dionato, is synthesized from the reactions of HN(CH2CH2NMe2)2, H-tmhd, and Sr(OEt)2(EtOH)4. Heating compound 1 at 130°C dissociates EtOH to form monomeric, seven-coordinate Sr(tmhd) 2[HN(CH2CH2NMe2)2] (2). A combination of thermogravimetric analysis (TGA) and thermal stability tests establishes that compound 2 is stable at temperatures below 220°C. In a cold-wall, low-pressure CVD reactor, 2 is used as a liquid precursor at 115 to 175°C to deposit high-k, dielectric, strontium hafnium oxide films in combination with the use of Hf(OtBu)4. The Sr/(Sr + Hf) atomic ratios of the films range from 0 to 0.83. X-ray diffraction (XRD) shows that films with low Sr doping, e.g., ≤ 0.15, exhibit a crystalline phase consistent with Sr-stabilized cubic hafnia, while films with higher Sr contents are amorphous. The dielectric constants of the films increase as the proportion of the cubic phase increases. A maximum value of 25 is obtained for the film with a Sr/(Sr + Hf) ratio of 0.07.

Original languageEnglish (US)
Pages (from-to)381-388
Number of pages8
JournalChemical Vapor Deposition
Volume13
Issue number8
DOIs
StatePublished - Aug 1 2007

Keywords

  • Hafnium oxide
  • High-k dielectric
  • Strontium oxide
  • Strontium precursor

Fingerprint

Dive into the research topics of 'Synthesis and structures of bis(2-dimethylaminoethyl)amine adducts of strontium bis(2,2,6,6-tetramethylheptane-3,5-dionate) and their use in the CVD of cubic strontium-doped hafnium dioxides'. Together they form a unique fingerprint.

Cite this