摘要 |
A method of anisotropic etching of silicon, the method comprising the steps of: partially covering at least one silicon surface 203 of a material to be etched with copper metal 205; and exposing the at least one surface to an aqueous etching composition comprising an oxidant and a source of fluoride ions. The source of fluoride ions is hydrogen fluoride. The copper, Cu, may be formed using an electroless deposition process. The use of copper metal on the surface of the silicon results in the etching process producing a surface consisting of silicon pillars 207, which can be detached and used in the production of rechargeable lithium-ion batteries. |