Change in surface morphologies with pulsed-laser-deposition-temperature for SrTiO3 and Ba0.7Sr0.3TiO3 thin films on Pt electrodes

Change in surface morphologies due to the growth temperature at which SrTiO3 and Ba0.7Sr0.3TiO3 thin films are formed on Pt electrodes by pulsed-laser deposition was investigated. The SrTiO3 and Ba0.7Sr0.3TiO3 films crystallized at temperatures as high as 350 and 450 degrees C, respectively, and their dielectric constants reached values higher than 200 and 300, respectively, above these temperatures. Two types of surface roughening were observed: one was extreme surface roughening indicating insufficient grain growth near the crystallizing temperatures, and the other was surface roughening due to the grain growth of the Pt bottom electrode above 400 degrees C which led to an increase in the leakage-current. (C) 1998 Elsevier Science S.A. All rights reserved.