Microstructure of (Ba,Sr)TiO3 thin films deposited by physical vapor deposition at 480 °C and its influence on the dielectric properties

The orientation and microstructure of (Ba, Sr)TiO3 (BST) deposited via physical vapor deposition at 480 degrees C was studied using x-ray diffraction, atomic force microscopy, and transmission electron microscopy. Annealing Pt/BST (previously annealed at 400 degrees C) at 800 degrees C in O-2 results in grain growth, enhancement of the {100} texture and a 20% increase in the dielectric constant. The 400 degrees C annealed films become more textured in the {100} orientation as film thickness is increased. Finally, it appears that an interfacial capacitance, rather than the bulk dielectric constant limits the total capacitance density of the films. (C) 2000 American Institute of Physics. [S0003-6951(00)01532-1].