Method for fabricating complex three-dimensional structures on the submicrometric scale by combined lithography of two resists

What is described is a lithographic method for fabricating three-dimensional structures on the micrometric and submicro-metric scale, including the operations of: depositing a layer of a first resist on a substrate; depositing a layer of a second resist on the layer of the first resist; forming a pattern of the second resist by lithography; depositing a further layer of the first resist on the previous layers; and forming a pattern of the first resist by lithography. The second resist is sensitive to exposure to charged particles or to electromagnetic radiation in a different way from the first; in other words, it is transparent to the particles or to the electromagnetic radiation to which the first resist is sensitive, and therefore the processes of exposure and development of the two resists are mutually incompatible to the extent that the exposure and development of one does not interfere with the exposure and development of the other.