Ferroelectric Bi3.15La0.85Ti3O12 (BLT) thin films were fabricated on SiO2/Si3N4/SiO2 substrates by a sol-gel spin coating method. The orientations of the BLT thin films were controlled by an intermediate rapid thermal annealing (RTA) process. The BLT thin films prepared using the RTA process at,400degreesC showed the (117) preferred orientation, while films preannealed at greater than or equal to450degreesC showed a stronger (006) peak than a (117) peak. A nearly perfect c axis orientation was obtained by RTA at >500degreesC and a subsequent furnace annealing at 700degreesC. It was found that 400 Angstrom thin BLT films with one layer coating were partially crystallized at even for a rapid thermal process temperature lower than 500degreesC. Transmission electron microscopy analysis indicated that c axis oriented nuclei were formed at 500degreesC RTA and these nuclei function as seeds in the growth of BLT films with an almost perfect c axis orientation during the final furnace annealing stage. The surface morphology of c axis oriented BLT thin films showed smooth and plate-like grains while rod-like shapes were observed in the (117) oriented films. (C) 2003 The Electrochemical Society.