Microstructured ceramic thin films are produced by spray pyrolysis of metal salt solutions onto micromachined substrates. The ceramic structures built on the substrate result from preferential assembly of particles on the edge of the initially micromachined structures, leading to smaller lateral dimensions (1-2 mu m in width) than the initial structures on the substrate (see figure). The assembly process amplifies the height of the initial structures by a factor of approximately thirty, resulting in features with an aspect ratio of three.