Thermal stability of ultrathin ZrO2 films prepared by chemical vapor deposition on Si(100)

As a function of thermal treatment, the chemical stability of ultrathin ZrO2 films prepared by chemical vapor deposition on a silicon substrate is investigated by x-ray photoelectron spectroscopy. The chemical structure is stable up to 800 degreesC in both vacuum and N-2 ambient, but a reaction forming zirconium silicide occurs above 900 degreesC in vacuum. The formation of silicide is accounted for by a reaction mechanism involving a reaction of ZrO2 with SiO, the latter formed above 900 degreesC at the interface between Si(100) and the thin layer of SiO2 formed during growth of the ZrO2. (C) 2001 American Institute of Physics.