According to one embodiment, the invention relates to a method for the anisotropic etching of patterns in at least one layer to be etched through a hard mask comprising carbon in an inductive-coupling plasma etching reactor (ICP), the method being characterized in that the hard mask is made from boron doped with carbon (B:C), and in that, prior to the anisotropic etching of the patterns in said layer to be etched through the hard mask of carbon-doped boron (B:C), the following steps are performed: realization of an intermediate hard mask situated on a layer of carbon-doped boron intended to form the hard mask made from carbon-doped boron (B:C), etching of the layer of carbon-doped boron (B:C) through the intermediate hard mask in order to form the hard mask made from carbon-doped boron (B:C), the realization of the intermediate hard mask and the etching of the hard mask made from carbon-doped boron (B:C) being done in said inductive coupling plasma etching reactor (ICP).