Characterization of Anisotropic Etching Effects of KOH Concentration and Temperature on Etching Profiles Properties of Silicon Corrugated Diaphragm

In this paper, silicon corrugated diaphragms with non-compensated mask layout have been designed and realized using anisotropic etching process simulator. The corrugated diaphragms have been etched on silicon (100) wafer by using potassium hydroxide solutions (KOH). The influence of the KOH etching temperature and concentration on the convex corner undercutting of corrugated diaphragm were observed. The convex corner behavior has been analyzed based on the geometrical parameters and the new emergent high index silicon planes. It was found that the convex corner undercutting phenomena is significantly reduced at low etching temperature and high KOH concentration respectively. It can be concluded that the prominent facets contributing to the undercutting of the convex corners of the corrugated diaphragm for the given etching condition coincide with the {411} plane.