| abstract |
A method of manufacturing etched silicon 103, the method comprising the steps of: electrolessly depositing a first metal onto a silicon surface 103, where the electrolessly deposited first metal (i.e. Cu, Au and Ag) partially covers the surface of the silicon 105; depositing a second metal (i.e. Cu, Au and Ag) that is different from the first metal over the silicon surface and the electrolessly deposited first metal. A film 107 of the deposited second metal covers the silicon surface 103 to be etched. The first metal and the second metal are removed from regions of the film of the deposited second metal 105, 107 that overlie the first metal to leave the second metal partially covering the silicon surface to be etched 107; and etching the silicon by exposing the silicon surface to an aqueous etching composition comprising an oxidant (ie O3,NO3,S2O8,NO2,B4O7 or ClO4) and a source of fluoride ions (ie HF) which may form etched pillars of Si 109 on the silicon surface 103. Porous or macroporous silicon may be used as a substrate. |