Properties of high-dielectric constant complex materials based on transition and rare-earth metal oxides

It was found in elemental transition or rare earth metal (TM/RE) oxides that the electrical and material properties are much poor than those of the conventional gate dielectric materials such as silicon oxide or oxynitride. It was also found that the electrical and material properties of the high-dielectric constant (high-k) films can be improved or compromised by using complex structures such as silicates, oxynitride, aluminate and titanate. This work reviews the properties of high-k MOS gate dielectric materials based on TM/RE complex oxides in either pseudo-binary or stoichiometric forms. The effects of doping with foreign atoms, such as nitrogen and aluminum, will also be discussed.