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
✍ Scribed by B. Luo; D. Yu; B. E. Kucera; S. A. Campbell; W. L. Gladfelter
- Book ID
- 102138513
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 371 KB
- Volume
- 13
- Category
- Article
- ISSN
- 0948-1907
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✦ Synopsis
Monomeric, eight-coordinate Sr(tmhd) 2 HN(CH 2 CH 2 NMe 2 ) 2 (1), where tmhd is 2,2,6,6-tetramethylheptane-3,5dionato, is synthesized from the reactions of HN(CH 2 CH 2 NMe 2 ) 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(CH 2 CH 2 NMe 2 ) 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-j, dielectric, strontium hafnium oxide films in combination with the use of Hf(O t Bu) 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.