High aspect ratio Si etching technique and application

Bulk silicon micromachining is becoming a hot topic in MEMS technology. This is mainly attributed to the breakthrough of high aspect ratio silicon etching. This article provides a new method of high aspect ratio silicon etching using fluorine based chemistries, SF₆ and C₄F₈, in an ICP system with a function of processing gases switching. The experiments demonstrate that the process results can meet most demands in bulk silicon micromachining processes. Two examples of a dry etching release process and fabrication of micro-silicon model are given to show the application of this technique