Initial stages of praseodymium oxide film formation on Si(0 0 1)

Pr2O3 may be an alternative high-K gate dielectric material for silicon integrated circuits, i.e., it has a dielectric constant K⩾25 and is currently under consideration as potential replacement for SiO2 as the gate dielectric material for sub-0.1 μm complementary metal-oxide-semiconductor technology. Using scanning tunneling microscopy and X-ray photoelectron spectroscopy, we show that the initial stages of heteroepitaxial Pr2O3 grown on Si(0 0 1) consist of a mixed PrO2/Pr2O3 phase. First ab initio calculation results also indicate the formation of an ultra-thin Si–O interlayer between the Si substrate and Pr2O3. In the monolayer range of deposited Pr2O3, Auger electron spectroscopy measurements show that the oxide is completely decomposed above 780 °C.