Perforated workpiece especially an optical or mechanical filter with micron or sub-micron size pores

摘要

A perforated workpiece, comprising a silicon substrate (1) having a first region (6) with through-pores (4) and a second region (7) with blind pores, is new. An Independent claim is also included for producing a perforated workpiece by electrochemically etching one face (2) of a silicon substrate (1) to form pores (4) of depth less than the substrate thickness, providing the opposite substrate face (3) with a mask layer which exposes first regions (6) of this opposite substrate face, etching the exposed face regions (6) to the bottoms of the pores (4) and then removing the mask layer.