Method for wet chemical etching of a semiconductor substrate

摘要

A method for wet chemical etching of a semiconductor substrate, in which convex structures (4) are produced on the surface of a semiconductor wafer (1) by using a suitable mask and a suitable etchant, is intended to make it possible to obtain convex geometries, especially those suitable for microlenses, on semiconductor substrate material with high reproducibility. An etching mask, consisting of an upper and a lower masking layer, is applied onto the semiconductor wafer (1). The upper masking layer (3) consists of photoresist and is used as a structuring mask for the lower masking layer (2). Using the structured two-layer etching mask (2, 3), etching is carried out in an etching solution with double etching action, in such a way that etching erosion of the lower masking layer (2), proceeding inwards uniformly from all sides, defines an etching front independent of the etching mechanism at the semiconductor material, and the structures (4) in the semiconductor wafer (1) take on a convex shape which is faithful to the mask. <IMAGE>