New and extended possibilities of orientation dependent etching in microtechnics

Abstract

We will demonstrate that the simple and inexpensive process of orientation dependent wet chemical etching can also be used for the preparation of more complex shapes and elements in microtechnics. In this way it is possible to apply unusual or any mask directions, multi-step etch processes by changing the mask or the etchant between the single steps, modified etchants (like etchants with inorganic or organic additives). The etch rates, the inclinations and the surface qualities of slow etching sidewall faces growing along mask edges in different directions and with different etchants are estimated. With the knowledge of the rates the etching process can be simulated for given mask dimensions and etch conditions.