Characteristics of ferroelectric Pb(Zr/sub 1-x/Ti/sub x/)O/sub 3/ thin film capacitors deposited on PtRhO/sub y/ electrode barriers

We present the feasibility of single-layer PtRhO/sub y/ thin films as electrode barriers for ferroelectric Pb(Zr/sub 1-x/Ti/sub x/)O/sub 3/ (PZT) (x = 0.2 to 0.8) thin film capacitors. PtRhO/sub y/ thin films were deposited directly on n+ Si wafers by means of the reactive sputtering method. PtRhO/sub y//PZT/PtRhO/sub y//n+ Si capacitors showed well-saturated P-E hysteresis loops. The remanent polarizations, as well as the polarization loss after the switching repetitions, were varied with the ratio of Zr/Ti. Especially, Pb(Zr/sub 0.4/Ti/sub 0.6/)O/sub 3/ thin film capacitor showed the superior ferroelectric properties, such as the shape of P-E hysteresis loops and the behaviors of the polarization fatigue. The typical remanent polarization and the coercive field of this capacitor were 22 /spl mu/C/cm/sup 2/ and 87 kV/cm, respectively, and the polarization loss was only less than 5 % after 10/sup 11/ switching repetitions. The chemical binding states of PtRhO/sub y/ films affected mainly the shape of P-E hysteresis loops. From the measurement of the depth profile and the microstructure of this capacitor, it could be convinced that single-layer PtRhO/sub x/ films behaved as high quality electrode barriers for PZT thin film capacitors.