In contrast to photolithography, the solution of e-beam lithography is practically unlimited by wavelength. Electrons of an energy of 25keV have a wave length of less than 0,01 nm. The maximum resolution thus is crucially determined by the beam diameter, which itself is defined by the electron source, the aberration of the electron optics and the interdependencies in the beam (Repulsion of electrons due to the same loading). Modern electron beam lithography systems can produce e-beams with cross sections in the area of a few nanometers. The achievable solution, however, is furthermore limited by the forward scattering of the electrons in the resist and the formed secondary electrons as well. The formation of secondary electrons cannot be avoided but the effect of forward scattering can be diminished by using higher acceleration stress and the application of thinner resist layers. However, the use of higher electron energies simultaneously results in a decrease of sensitivity, since higher-energy electrons interact less strongly with the resist layer and are practically shot through the resist.
Overview E-beam Other Resists