Abstract.
Anisotropic wet-chemical etching of silicon in alkaline solutions is
a key technology in the fabrication of sensors and actuators. In earlier
work it was found that not only the etchant and temperature determine the
exact anisotropy of etched silicon; the angle between the silicon surface
and the mask was also shown to play an important role. In this paper this
phenomenon was quantified for several etching conditions. Also, the etch
rates of Si{ 100} and Si{ 110} were determined under these conditions,
together with the activation energies of these orientations. Finally, the
anisotropy ratios (etch depth/underetch) of the etched samples were determined.