Method for indexing dies comprising integrated circuits

A method for indexing a plurality of dies obtainable from a material wafer comprising a plurality of stacked material layers, each die being obtained in a respective position of the wafer, the plurality of dies being obtained by means of a manufacturing process performed in at least one manufacturing stage using at least one lithographic mask for treating a surface of the material wafer through an exposition to a proper radiation, said at least one manufacturing process comprising at least two steps for treating a respective superficial portion of the material wafer that corresponds to a subset of said plurality of dies using the at least one lithographic mask through the exposition to the proper radiation in temporal succession, the method including providing a die index on each die which is indicative of the position of the respective die, said providing a die index on each die comprising forming an external index indicative of the position of the superficial portion of the material wafer corresponding to the subset of the plurality of dies including said die, said forming the external index comprising:

• forming in a set of material layers of the die a first reference structure that defines a mapping of the superficial portions of the wafer, said first reference structure comprising a plurality of transistors having control terminals electrically coupled to each other using a respective common control line;
• and
• interrupting the common control line in a position based on the position of the superficial portion corresponding to the subset of the plurality of dies including the die.