A Silicon Texturing Technique Based on Etching Through a Liquid-Phase Deposited Oxide Mask

Abstract

This work presents an electrochemical etching technique for silicon ͑Si͒ surface texturing that simultaneously occurs during the liquid-phase deposition ͑LPD͒ of silicon dioxide ͑SiO 2 ͒ on the surface. The method relies on an isotropic electropolish etching through self-defined micropores evolved in the LPD oxide mask, leading to a uniform texture, without requiring any patterning. Hydrofluorosilicic acid/ethanol electrolyte has been used in the etching process. Orientation-independent texturing was successfully realized on spherical Si single crystals for potential application in photovoltaics. The characteristics of Si surface texture and LPD SiO 2 layer were investigated by energy-dispersive spectroscopy, scanning electron microscopy, atomic force microscopy, and Fourier transform IR.