Fabrication of Sio2-based microcantilevers by anisotropic chemical etching of (100) single crystal Si

Abstract

The undercutting process of thermal SiO2 microcantilevers with different orientations on (100) Si wafer was studied. The silicon substrate was removed by anisotropic chemical etching with a 25 wt. % aqueous solution of TMAH or a 30 wt. % aqueous KOH solution at 80 °C. It was found that [110] oriented cantilevers were undercutting frontally along the length and [100] oriented cantilevers experience undercutting along the width of the cantilever, which is a less time consuming process. The studies showed that the [100] orientation of SiO2 microbridges enables theirs fabrication on a (100) oriented Si substrate.

Keywords

• anisotropic wet chemical etching
• tmah
• koh
• sio2 microcantilever
• sio2 microbridge
• (100) oriented si substrate