First-principles theoretical evaluation of crystalline zirconia and hafnia as gate oxides for Si microelectronics

摘要

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