Method for producing and/or renewing an etching mask

A method for etching a substrate, which comprises:

• a) applying a reflective layer to the substrate;
• b) applying a first photoresist layer to the reflective layer;
• c) producing an etching pattern on the first photoresist layer and developing the first photoresist layer to form the first etching mask;
• d) etching the reflective layer with the first etching mask;
• e) etching the substrate with the first etching mask;
• f) interrupting the etching process before the first etching mask formed by the first photoresist layer or before the reflective layer is consumed;
• g) applying a second photoresist layer;
• h) exposing the substrate coated with the second photoresist layer, such that areas which have been exposed once are not yet completely exposed and areas of the second photoresist layer which have been additionally exposed due to the reflective layer are exposed completely;
• i) developing the second photoresist layer to form a second etching mask corresponding to the first etching mask;
• and
• optionally repeating the sequence, starting with the etching of the coated substrate but with the second etching mask, until a desired structure depth is achieved in the substrate.