Chemical vapor deposition of high-k oxide films using novel anhydrous mental nitrates as precursors

Anhydrous Ti,Zr and Hf nitrates with good volatility have been successfully synthesized by the reactions of their corresponding metal chlorides with dinitrogen pentoxide.Using these carbon-free inorganic compounds as precursors,TiO2,ZrO2 and HfO2 films with good dielectric properties have been successfully deposited by the chemical vapor deposition(CVD)technique.Using these precursors,gate dielectric films can be directly deposited on Si substrates at lower temperatures without the introduction of oxidative gases such as O2,O3,and thus can effectively avoiding the formation of low dielectric constant interfacial layers.These results suggest that these anhydrous metal nitrates can be promising precursors for the CVD of high-k gate dielectric films.