Electron Beam Lithography
Electron beam lithography (EBL) is a method for creating ultra-fine, nanometer-sized structures in modern nanotechnology. It is an important instrument in semiconductor technology, used to produce photomasks for photolithography, or stamps for other lithographic processes. The EBL is based on the conventional scanning electron microscope, but rather than scanning over the sample line by line as is the case for imaging, the beam path is defined by the structural geometry. Accordingly, it is a very flexible, albeit expensive, serial process.
One major benefit of the EBL is its very high resolution, which is not limited by diffraction. This is used in semiconductor technology to produce nanostructures on silicon: for this purpose, the silicon is first covered with a thin layer of photoresist, which is then structured by the electron beam (Figure 2b I). The structured photoresist is partially removed by development (Figure 2b II) and the inscribed pattern is subsequently transferred to the silicon through etching (Figure 2b III).