The application of secondary effects in high aspect ratio dry etching for the fabrication of MEMS

With increasing aspect ratio of etched features, secondary effects of plasm a etching, such as RIE-lag or aspect ratio dependent etching (ARDE), become more important for etching processes for the fabrication of microelectrome chanical systems (MEMS). Furthermore, the etching behavior, which is repres ented in the profile slope, sidewall surface quality and etching rate, depe nds not only on the aspect ratio of the etched trenches or features but als o on their design and the pattern density. We discuss these effects and pro pose ways to use them in order to expand the variability of etching process es and to overcome their disadvantages. (C) 2001 Elsevier Science BY All ri ghts reserved.