Metallic submicrometer sieves fabricated by interferometric lithography and electroforming

We propose and demonstrate a low cost technique to fabricate submicrometer sieves using the association of laser interference lithography and nickel electroforming. The sieves are fabricated on glass substrates and are released from the substrate by adding a hexagonal sustaining structure, electroformed in nickel, using conventional lithography. The resulting sieves are free self-sustained membranes similar to those used in filtration devices, with typical diameters of the holes of about 250 nm and areas of about I cm(2).