ANISOTROPIC ETCHING OF SILICON-CRYSTALS IN KOH SOLUTION .2. THEORETICAL 2-DIMENSIONAL ETCHED SHAPES - DISCUSSION OF THE ADEQUATION OF THE DISSOLUTION SLOWNESS SURFACE

Theoretical two-dimensional etched shapes are derived from numerical s imulations involving the equation of the dissolution slowness surface related to silicon crystals etched in aqueous KOH solutions. Theoretic al changes in cross-sectional shapes of starting circular sections and in x'1 and [001] profilometry traces with the angle of cut, phi0, are analysed in terms of the geometrical features of the slowness surface . The important role played by extrema in the dissolution slowness in determining the final two-dimensional etched shapes, is outlined. Theo retical etched shapes are systematically compared with the experimenta l shapes and the adequation of the proposed slowness surface is discus sed.