Novel technique to study the wet chemical etching response of multi-crystalline silicon wafers

Abstract

This study is based on the application of a combinatory method for surface and crystallinity analysis of crystalline materials. The obtained results illustrated the effects of different additives (isopropyl alcohol (IPA) and sodium hypochlorite (NaOCl)) to a KOH solution, on the crystalline Si chemical etching process. IPA had a texturing effect for mono-crystalline Si, while NaOCl demonstrated a polishing effect for this material. For multi-crystalline silicon materials, we found that the etching rate of the individual silicon grains is affected by their crystallographic similarity with one of the three main crystal orientations (100, 110, 111). In addition, an optimal polishing effect of multi-crystalline Si was demonstrated by mixing IPA and NaOCl additives in the KOH based solution.