E. Rokuta et al., Ferroelectric Bi4Ti3O12 films on Si(100) with an ultrathin buffer layer ofsilicon oxynitride: A comparative study using X-ray photoelectron spectroscopy, JPN J A P 1, 40(9B), 2001, pp. 5564-5568
Using pulsed-laser deposition, ferroelectric B4Ti3O12 (BiT) films were grow
n on Si(100) with and without an ultrathin buffer layer of silicon oxynitri
de (SiON), and the interface states were investigated using X-ray photoelec
tron spectroscopy. For both as-grown specimens, the additional oxidation of
the interface Si was observed, and their thicknesses were almost identical
. Due to the postannealing at 700 degreesC in an oxygen ambient, on the oth
er hand, a large difference in the Si oxidation was observed between the tw
o specimens. The BiT films on Si(100) without the SiON buffer layer failed
in preventing the significant development of the interfacial Si oxidation.
On the contrary it was clarified that the 1.3-nm-thick SiON buffer layers s
uppressed the additional oxidation to less than 3.5 nm.