RMnO3 (R = Y, Yb) thin films were prepared by chemical solution deposition using alkoxy-derived precursors. The crystallization behavior, orientation and morphology of YMnO3 films depended on the annealing conditions. It v as confirmed that heat treatment in vacuum at the initial stage of crystallization affected the restraint of the perovskite phase and the formation of the hexagonal phase, and the following heat treatment in oxygen promoted c-axis orientation and grain growth. In contrast, YbMnO3 films crystallized in the hexagonal phase both in vacuum and oxygen. The orientation of the YbMnO3 films did not strongly depend on the annealing ambience compared with that of YMnO3 films. The substitution of Y ion by Yb ion made it easy to form the hexagonal structure. However, the surface roughness became larger. The lattice constant of c-axis increased and that of a-axis decreased as the Yb ratio increased. (C) 2002 Elsevier Science B.V. All rights reserved.