Electron beam lithography (EBL) is a type of nanofabrication technique used to pattern materials at the nanoscale. It uses a finely focused beam of electrons to draw patterns on a substrate, such as a silicon wafer. By controlling the beam's intensity and pattern, complex patterns can be created with very high resolution. It is used to produce intricate structures and patterns for circuit components in the semiconductor industry, as well as for a variety of other applications.