Fabrication and investigation of ultrathin, and smooth Pb(Zr,Ti)O(3) films for miniaturization of microelectronic devices

Abstract

Pb(Zr0.52Ti0.48)O-3 (PZT) thin films were fabricated on Pt(111)/TiOx/SiO2/Si substrates at 375 degreesC by radio frequency magnetron sputtering. A mixture of (110) and (100) orientations was found in all the PZT thin films. However, the in-plane grain size increased with an increase in film thickness, all films had smooth surfaces, and the root mean square roughness of the PZT films was in the range of 1-1.5 nm. As the film thickness increased, a decrease in residual stress and volume density of the PZT films was observed. PZT films become poorly crystallized with a decrease in film thickness. The magnitude of the maximum displacement from atomic force microscopy in local piezoresponse hysteresis mode increased from 187.25+/-9.363 in 40 nm to 418.5+/-20.925 in 152 nm. We suggest that the degradation in piezoelectric properties with a decrease in film thickness resulted from degradation of the crystallinity observed using transmission electron microscopy analysis, size effects derived from the grain size, and the residual stress evaluated using a laser reflectance method. (C) 2002 American Institute of Physics.