Effect of low temperature and concentration KOH etching on high aspect ratio silicon structures

In this paper, the effect of low concentrated alkaline solutions etching on texturized silicon structures at low temperatures has been studied. The silicon samples have been previously etched either from regular arrays by HF anodization on prepatterned substrates or by Deep Reactive Ion Etching (DRIE). After immersion in a low concentrated potassium hydroxide (KOH) solution mixed with isopropyl alcohol (IPA), the quality of the silicon sidewalls has been improved by an anisotropic etching. Thus, the trenches wall surface has been smoothed and planed.