Interface Effects of Pb(Zr,Ti)O3Thin Film Capacitors with Pt, IrO2and SrRuO3Top Electrodes

The crystalline defects of electrode/ferroelectric interface of PZT thin film capacitors with Pt, IrO 2 and SrRuO 3 (SRO) top electrodes were investigated by TEM-EDX analysis. The interface of Pt/PZT and IrO2/PZT had an ideal interface structure, and formed good Schottky barriers. However, the Schottky barrier was not formed at the SRO/PZT interface. Because Ru diffused into the PZT surface, and this joint like Ohmic contact was formed. Moreover, a Sr-rich SRO layer of about 10 nm existed in interfacial neighborhood. This alteration layer influenced dielectric dispersion, and caused a remarkable bias dependency for the C-V characteristics.