Property Improvement of Mocvd-Pzt Films Deposited Below 400 °C

Abstract

ABSTRACTRuO2/(200-nm thick PZT)/RuO2 capacitors were prepared by MOCVD. RuO2 and PZT films were prepared at 350, and 395 and 445 °C from DER - O2 and Pb(C11H19O2)2 - Zr(O·t-C4H9)4 - Ti(O·i -C3H7)4 - O2 systems, respectively. Clear hysteresis loops originated to ferroelectricity was observed for the PZT films deposited at 445 °C but was not at 395 °C. However, by the addition of 10-nm thick Pt layer prepared on the RuO2 bottom electrode by e-beam evaporation, ferroelectricity above 30 μC/cm2 in remanent polarization (Pr) was obtained for the PZT films deposited at 395 °C. This shows that the existence of Pt layer improved the crystallinity of PZT phase. This capacitor shows hardly fatigue up to 1 × 1010 switching cycles, suggesting the fatigue free characteristics.