Microstructure and Crystallization Behavior of Sol-Gel Prepared BaTiO3 Thin Films

Abstract

ABSTRACTThin films of BaTiO3 were prepared by the sol-gel route using barium titanium methoxypropoxide in methoxypropanol. Sols with water of hydrolysis varying between h=0 and h=2 were spun onto (100) Si and Ge coated (100) Si substrates. XRD and analytical TEM were used to study the microstructure and crystallization behavior of these films. Polycrystalline BaTiO3 was obtained by heat treating the films at temperatures between 600 and 750°C using either conventional furnace annealing or rapid thermal annealing. Films prepared from sols having the highest water content tended to crystallize first. The BaTiO3 thin films exhibited a fine grain size on the order of 25–50 nm. No preferred orientation was observed. The effects of the hydrolysis conditions of the sol, the type of heat treatment, and the choice of substrate on the final microstructure of the films are discussed.