Atomic layer chemical vapor deposition (ALCVD) of hafnium silicate films using a precursor combination of tetrakis (diethylamido) hafnium,
Hf(normalN(C2H5)2)4
, and tetra-
n
-butyl orthosilicate,
Si(OnBu)4
was studied for high-dielectric gate oxides. The ALCVD temperature window in our study was 290-350°C with a growth rate of 1.1 Å/cycle. We investigated the effect of deposition conditions, such as deposition temperature, pulse time of precursor, and purge injection, on the film growth. The saturated composition of the Hf/
(Hf+Si)
ratio was 0.37, and the impurity concentrations were less than 1 atom %. The dielectric constant
(k)
of the as-deposited hafnium silicate film increased upon annealing at 600°C, but decreased for annealing above 800°C. Hysteresis in the capacitance-voltage measurements was less than 0.3 V before and after annealing. The leakage current density of the as-deposited, 600°C, and 800°C annealed films was
5.3×10−2
,
2.2×10−2
, and
2.7×10−60.3emnormalA∕cm2
, respectively, at a bias of −1 V.