NaWoTec GmbH was a spin-off from the central research unit of Deutsche Telekom AG. The company developed a process to build surface structures at the dimension of nanometers. This was achieved by initiating and controlling highly precise chemical reactions at the focal point of an electron beam (e-beam). By controlling the e-beam, very complex 3D structures could be built with sizes down to 4nm. The NaWoTec Nano-structuring technology consisted of both deposition and taking away material by etching. Core applications for this technology were in the semiconductor manufacturing process and included the repair of photolithography masks for wafer processing. In May 2005 the company was very successfully sold to Carl Zeiss AG.