Realization of perfect silicon corrugated diaphragm using KOH etching

This article presents corner compensation mask design in order to realize perfect silicon corrugated diaphragm using KOH etching technique. The corner undercutting of silicon (100) in KOH is quite serious and without compensation it is difficult to construct a complete convex corner structures since the silicon diaphragm is etched from both top and bottom directions in order to form the corrugated structure. The introduction of the additional mask layout for the protection of convex corners at all convex-mask geometry of the corrugated diaphragm during the KOH etching process has been proved by simulation to produce almost perfect square corners.