A method to evade silicon backside damage in deep reactive ion etching for anodically bonded glass–silicon structures

Abstract

Due to the microloading effect, an overetch in through-wafer etchings by deep reactive ion etching (DRIE) has to be considered in the fabrication of glass–silicon structures, which results in damages of the silicon surfaces exposed to an ion bombardment. This paper reports on a new method, in which a metal layer is located on the glass surface and electrically connected with the silicon substrate. Although, structures are overetched for a long time, the silicon surfaces remain intact. The results show interdependency between the position of the metal layer on the glass surface and the gap separating the silicon and glass surfaces.