A method for producing patterns in a layer to be etched, from a stack including at least the layer to be etched and a masking layer overlying the layer to be etched, with the masking layer having at least one pattern. The method includes modifying a first area of the layer to be etched by ion implantation through the masking layer; depositing a buffer layer to cover the pattern of the masking layer; modifying another area of the layer to be etched, different from the first area, by ion implantation through the buffer layer, to a depth of the layer to be etched greater than the implantation depth of the preceding step of modifying; removing the buffer layer; removing the masking layer; removing the modified areas by etching them selectively to the non-modified areas of the layer to be etched.