Realization of 3D silicon structures using a DRIE technique

3D manufacturing at micron scale with very low roughness is a key enabling technology for the realization of micromechanical parts both for mechanical devices and for critical components such as printer head nozzles and high precision molds. The only currently available technique in the field of IC micro technology is nanolithography by two photon absorption [1]. We report the implementation of a technique based on multiple Deep Reactive Ion Ecthing (DRIE) [2] that allows to realize complex 3D geometries in silicon with a limited number of lithographic steps. A mold is demonstrated with 1/30 aspect ratio, 6 depth levels, including wafer-through features, with a dimensional accuracy of 5um.