Characteristics of (Pb,Sr)TiO3∕ZrO2 structures on Si and SiON∕Si substrates

The ferroelectric (Pb,Sr)TiO3 (PST) thin film with ZrO2 insulating buffer on Si and SiON(3nm)∕Si substrates was fabricated by rf magnetron sputtering. ZrO2 demonstrates excellent insulating properties on either Si or SiON∕Si substrates. The metal-ferroelectric-insulator-semiconductor structure shows low leakage currents and exhibits clockwise capacitance-voltage hysteresis loops which are due to the ferroelectric polarization of the PST films. The maximum memory windows of the hysteresis loops are 0.8 and 1.37V, respectively for PST∕ZrO2 films on Si and SiON∕Si substrates. This is of potential as memory devices. The charge injection effect under large sweeping voltages is discussed.