  Parameters determining the performance of the crystalline oxides zirconia
(ZrO_2) and hafnia (HfO_2) as gate insulators in nanometric Si electronics are
estimated via ab initio calculations of the energetics, dielectric properties,
and band alignment of bulk and thin-film oxides on Si (001). With their large
dielectric constants, stable and low-formation-energy interfaces, large valence
offsets, and reasonable (though not optimal) conduction offsets (electron
injection barriers), zirconia and hafnia appear to have a considerable
potential as gate oxides for Si electronics.
