Effects of zirconium substitution on the electrical and physical properties of metal-ferroelectric (BiFeO₃)-insulator (HfO₂)-silicon structures for non-volatile memories

Metal-ferroelectric (Zr-doped BiFeO₃)-insulator (HfO ₂)-semiconductor (MFIS) structures have been fabricated by magnetron cosputtering technique. The C-V memory windows of MFIS capacitors as functions of insulator film thickness, DC power for Zr, post-annealing temperature were compared. The leakage current that reduces with increasing the DC power results in larger memory window. The memory window increases with increasing HfO ₂ insulator thickness due to the effect of charge injection. In addition, the memory window increases with increasing DC power for Zr. A maximum memory window of 1.6 V is obtained at the swept voltage of 8 V. The temperature-dependent conduction currents of MFIS capacitors with Zr-doped BFO thin films were studied.