TY - JOUR
T1 - 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
AU - Luo, Bing
AU - Yu, Dan
AU - Kucera, Benjamin E.
AU - Campbell, Stephen A.
AU - Gladfelter, Wayne L.
PY - 2007/8
Y1 - 2007/8
N2 - 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.
AB - 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.
KW - Hafnium oxide
KW - High-k dielectric
KW - Strontium oxide
KW - Strontium precursor
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U2 - 10.1002/cvde.200606577
DO - 10.1002/cvde.200606577
M3 - Article
AN - SCOPUS:54949090028
SN - 0948-1907
VL - 13
SP - 381
EP - 388
JO - Chemical Vapor Deposition
JF - Chemical Vapor Deposition
IS - 8
ER -