Abstract.
Makyoh-topography studies of the deformations in dielectric membrane structures are reported. First, a geometrical optical model of the Makyoh image formation mechanism is presented, and the fundamental properties of imaging are established. Methods for the measurement of overall curvature and the reconstruction of the surface profile from the observed images are described. The construction of a Makyoh-topography set-up is detailed. Then, the study of the deformations of dielectric membranes and structures is reported. It is shown that Makyoh is suitable to detect and quantify the deformations of the whole wafer, the individual membranes as well as the substrate areas adjacent to the membranes. For small membranes and strongly patterned structures, the imaging is limited by diffraction effects; however, qualitative study is still possible. Examples of process monitoring during membrane fabrication are presented as well.