Method for producing patterns in a substrate

A method for structuring a front face of a substrate by producing at least one pattern on the front face of the substrate, the method comprising:

• providing a substrate having a front face surmounted by at least one masking layer;
• defining at least one mask pattern in the masking layer such that the masking layer comprises adjacent regions having different height levels;
• producing an ion implantation of the substrate by the front face and at least to the right of the mask pattern, so as to form at least one first zone modified by implantation and at least one second zone not modified by implantation or less modified than the at least one first zone, the implantation conditions being selected such that after implantation, the at least one first zone has a resistivity ρ1 less than a resistivity ρ2 of the at least one second zone;
• removing the masking layer such that the front face of the substrate is stripped;
• and
• at least the following successive steps:
• after the ion implantation, immersing the substrate in an electrolyte such that the stripped front face of the substrate is fully in contact with the electrolyte, and
• removing the at least one first zone selectively at the at least one second zone so as to form on the front face of the substrate, the at least one pattern of which a geometry is according to the mask pattern, said removing comprising at least an application of an electrochemistry step on the substrate to cause a porosification of the at least one first zone selectively at the at least one second zone, said removing being carried out such that at least during the electrochemistry step, at least one rear face of the substrate opposite the front face has charge carriers.