Charge transport in thin hafnium and zirconium oxide films.

The mechanism of charge transport in MIS structures on the basis of thin hafnium and zirconium oxide films is studied. It is shown that transport in the studied materials is limited by phonon assisted tunneling between traps. From the comparison of experimental current-voltage characteristics of MIS structures n-Si/HfO/Ni and n-Si/ZrO/Ni, the estimated, thermal, and optical energies of traps are determined. It is shown that oxygen vacancies are localization centers (traps) of charge carriers in HfO and ZrO. [ABSTRACT FROM AUTHOR]