Effect of the silicon content of aqueous KOH on the etching behaviour of convex corners in <100> single crystalline silicon

In this paper we investigate the effect of accumulating silicon in the aqueous KOH solution on the etching behaviour of single crystalline silicon. The etch rate of the {100} planes was not much affected by the silicon concentration. The bevelling planes that form at convex corners can not be identified as simple crystal planes. The appearance of etched convex corners begins to change when the silicon concentration is higher than 58 mg/cm³. When the silicon content exceeds 160 mg/cm ³ only rugged surfaces develop at convex corners. Undercutting of convex corners is much more pronounced with increasing silicon content