Improvement of Ferroelectric and Electrical Properties of Sol-Gel deposited Bi_4Ti_3O_(12) Thin Films by Multiple Rapid Thermal Annealing Techniques

摘要

Ferroelectric Bi_4Ti_3O_(12) thin films were fabricated by sol-gel method with multiple rapid thermal annealing (MRTA) techniques on Pt/Ti/SiO_2/p-Si substrates. The effect of annealing temperature on crystallinity, ferroelectric and electrical properties of Bi_4Ti_3O_(12) films derived by MRTA and by normal RTA were investigated. The results reveal that the grain size and the roughness of surface increase with the annealing temperature increase, but the maximal remnant polarization of Bi_4Ti_3O_(12) films come forth when the annealing temperature is 650_i. The perovskite phase of Bi_4Ti_3O_(12) films were formed at lower annealing temperature and smaller grain size were obtained in the BIT thin films prepared by MRTA compared with that by normal RTA. The typical values of remnant polarization of Bi_4Ti_3O_(12) films derived by MRTA was 11μC/cm~2, which was higher than that derived by conventional RTA about 15%, while the leakage current density was 8.9 x 10~(-9) A/cm~2 by MRTA, which was lower than that by normal RTA about 90%.