Acidic texturing of multicrystalline silicon wafers

In this paper, results from investigations of acidic texturing are presented. As-cut, multicrystalline and polished, single crystal Si wafers have been etched in a range of acidic mixtures. The mixtures contained hydrofluoric and nitric acid, with de-ionized water, phosphoric acid or sulphuric acid added as diluents. In the initial phases of the etching process, surface cracks originating from the wafer sawing were transformed into deep and elongated pits. The reflectance of such textures was low. However, as the etching proceeded beyond the damaged surface region, more reflective, bubble-like textures were obtained.