Enhancement in ferroelectric properties of Pb(Zr0.4Ti0.6.O3) thin-film capacitors with PtOx electrodes

The characteristics of sputtered PtOx electrodes and the ferroelectric reliability of Pb(Zr0.4Ti0.6)O-3 (PZT) thin-film capacitors for memory application in relation to the oxygen content in the electrodes were investigated. The PZT thin films of 130 nm thickness were deposited on PtOx electrodes. Both Pt and PtO phases coexist and a compressive stress is also induced in the electrode after rapid thermal annealing (RTA) at 600 degrees C. The polarization-switching characteristics, including polarization value and switching rate of PZT capacitor, are improved by using the PtOx as electrodes, especially for the bottom electrode, in comparison to that made with Pt electrodes. In addition to the enhancement in polarization-switching characteristics, the properties of fatigue endurance were tested at room temperature. High fatigue endurance (97% of initial remnant polarization remains after 10(10) cycles) can also be achieved for the capacitors having both top and bottom electrodes made with PtOx having a high oxygen content. (C) 2006 The Electrochemical Society.