Synthesis and properties of dielectric (HfO2)1 − x(Sc2O3)x films

• Published in: Inorganic materials Vol. 49; no. 2; pp. 172 - 178
• Main Authors: Yakovkina, L. V., Smirnova, T. P., Borisov, V. O., Kichai, V. N., Kaichev, V. V.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01-02-2013
• Subjects: Chemical vapor deposition; Chemistry; Chemistry and Materials Science; Crystal structure; Density; Dielectric constant; Industrial Chemistry/Chemical Engineering; Inorganic Chemistry; Insulators; Leakage current; Materials Science; Permittivity; Scandium; Dielectric Permittivity; Scandium Content; Leakage Current Density; Hafnium; Scandium
• ISSN: 0020-1685; 1608-3172
• DOI: 10.1134/S0020168513020234

(HfO
2
)
1 −
x
(Sc
2
O
3
)
x
films have been grown by chemical vapor deposition (CVD) using the volatile complexes hafnium 2,2,6,6-tetramethyl-3,5-heptanedionate (Hf(thd)
4
) and scandium 2,2,6,6-tetramethyl-3,5-heptanedionate (Sc(thd)
3
) as precursors. The composition and crystal structure of the films containing 1 to 36 at % Sc have been determined. The results demonstrate that, in the composition range 9 to 14 at % scandium, the films are nanocrystalline and consist of an orthorhombic three-component phase, which has not been reported previously. Using Al/(HfO
2
)
1 −
x
(Sc
2
O
3
)
x
/Si test structures, we have determined the dielectric permittivity of the films and the leakage current through the insulator as functions of scandium concentration. The permittivity of the films with the orthorhombic structure reaches
k
= 42–44, with a leakage current density no higher than ∼10
−8
A/cm
2
.