Effect of oxygen content and thickness of sputtered RuOx electrodes on the ferroelectric and fatigue properties of sol-gel PZT thin films

Sol-gel PZT thin-film capacitors with reactive sputtered RuOx electrodes were fabricated. The ferroelectric and fatigue properties of the capacitors were investigated with various oxygen content in the electrodes and different electrode thickness. Our results show that increase in oxygen content in the electrodes would improve the fatigue properties of the capacitors and the remanent polarization shows a maximum at a 10% oxygen partial pressure. These fatigue results are consistent with the oxygen vacancy model. Considerable degradation in ferroelectric and fatigue properties of the capacitors was observed when the electrode thickness was below 230 nm. Oxygen deficiency in the thin electrodes was detected through AES measurement. We propose that the effect of electrode thickness is attributed to the oxygen diffusion in the bottom electrode layers. (C) 1999 Elsevier Science S.A. All rights reserved.