E-beam lithographic procedures

There are both mask-based and maskless writing procedures in electron beam lithography. For direct, maskless writing, older systems use electron beams with Gaussian energy distribution, which are directed over the substrate in the grid. More up-to-date systems use defined beams with, by the application of masks, selectively adjusted geometrical cross sections or respectively profiles, which are deflected upon the various positions (vector scan mode). The deflection of the electron beam is achieved by electrostatic interdependence of the electrons.

The used, variously shaped electron beams differ with regard to their energy distribution in the beam cross section in fixed shape beams on one hand (round, Gauss beams, square shape, round spot with steady energy distribution) and, on the other hand, beams of variable shape (mostly triangles or quadrangles of various sizes and form. The shape of the beam is generated by an aperture or respectively a structured aperture plate.

Similar to photolithography, there are specific proximity exposure techniques in mask-based procedures, such as 1:1 projection or also other projections in which the structures of the mask are downsized.