Fabrication and characterization of metal-ferroelectric (PbZr0.53Ti0.47O3)-Insulator (Y2O3)-semiconductor field effect transistors for nonvolatile memory applications

Metal-ferroelectric-insulator-semiconductor (MFIS) field effect transistors with Pb(Zr0.53,Ti0.47)O3 (PZT) ferroelectric layer and yttrium oxide Y2O3 insulator layer were fabricated. The maximum C-V memory window of 1.5V was obtained at a sweep voltage of 8V. The dominating conduction mechanism through the MFIS structure is Schottky emission in the temperature range from 300to450K. The nonvolatile operation of MFIS transistors was demonstrated by applying positive/negative writing pulses. The retention shows that the transistors maintain a threshold voltage window of 1.2V without deterioration after 3×103s. The low leakage current and the high effective Y2O3∕Si barrier height of 1.85eV can well explain the size of memory window and retention properties. The effect of charge injection is reduced in this structure.