Abstract

In this paper a study of the anisotropic dissolution of (hk0) and (hhl) silicon plates in a NaOH 35% solution is undertaken. Effects of orientation on firstly, the geometrical features of etched surfaces and secondly, on the cross-sectional shape of starting circular plates are systematically investigated. Conclusions of practical interest on the roughness of etched (hk0) and (hhl) planes are drawn. 2D etching shapes are then analysed in terms of the tensorial model for the anisotropic dissolution and of dissolution criteria. Finally a comparative analysis of results related on the one hand, to 2D surface profiles and on the other, to out-of-roundness profiles is made. This comparison shows that shapes observed for profilometry traces agree with theoretical shapes as derived when we use the resemblance in shapes between out-of-roundness profiles and polar diagrams of the dissolution slowness.