Pseudopotential study of PrO2 and HfO2 in fluorite phase

Praseodymium and hafnium oxides are prospective candidates to subsitute SiO2 in decanano MOSFET transistors. We report first ab initio pseudopotential band structure calculations for these materials. We find that fluorite phases of PrO2 and HfO2 have similar electronic structures, The important difference is a narrow sub-band forming the conduction band bottom in PrO2, but absent in HfO2. Electrons in this f-type sub-band have large masses. This explains why ultrathin epitaxial Pr oxide films have low leakage in spite of a relatively small conduction band offset (similar to1 eV) between the oxide and the Si substrate. (C) 2001 Elsevier Science Ltd. All rights reserved.