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

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