J. Aarik et al., Phase transformations in hafnium dioxide thin films grown by atomic layer deposition at high temperatures, APPL SURF S, 173(1-2), 2001, pp. 15-21
High-temperature cubic phase of HfO2 was observed by reflection high-energy
electron diffraction in nanocrystalline thin films grown by atomic layer d
eposition from HfCl4 and H2O at substrate temperatures of 880-940 degreesC.
The phase was formed at properly chosen precursor doses and it was observe
d on the surface of films, which according to X-ray diffraction data consis
ted of monoclinic HfO2. The thickness of the surface layer, in which the cu
bic phase appeared, was estimated to be 5-10 nm. According to Auger electro
n spectroscopy data, formation of the cubic phase was accompanied with an i
ncrease in the ionicity of O-Hf bonds. (C) 2001 Elsevier Science B.V. All r
ights reserved.