Effect of heat-treatment on LaNiO{sub}3 film electrode of PZT thin films derived by a sol-gel method

摘要

Lanthanum nickel oxide (LaNiO{sub}3 or LNO) conducting thin films that could be used as electrodes for improving fatigue and aging properties of ferroelectric thin films were investigated. In this paper, LNO films were directly spin-coated onto SiO{sub}2/Si(1 00) substrates followed by thermal treatment in air and in oxygen. It was found that crack-free dense and uniform films with good crystallinity and medium grains were obtained, preferentially (1 00)-oriented LNO thin films could be formed at a lower annealing temperature of 550℃ and that with the increase in thermal annealing temperature the LNO thin film possessed better electrical properties especially at 750℃. However, the LNO film displayed a structure transformation above 850℃. A phenomenon was found that the first heat-treatment temperature and time played a key role to determine the crystallite size of LNO films. A subsequent deposition of a sol-gel derived Pb(Zr{sub}0.53Ti{sub}0.47)O{sub}3 (PZT53/47) thin film on the LNO-coated SiO{sub}2/Si(1 00) substrates was also found to have a (1 00)-oriented texture. Moreover, the Au/PZT/LNO capacitor was found to significantly improve the fatigue and the effects of the LNO electrodes to the fatigue were discussed.