Cell projection lithography with scattering contrast

A scattering-type cell projection method is proposed and its characteristics are estimated by simulation and experiment. In this method, a mask consisting of thin scatterers and apertures is used to shape an electron beam. Thus, this method has advantages over the conventional cell projection method. First, a high aspect ratio is not necessary to fabricate the mask. Thus, the mask pattern is easily fabricated and its experimental dimensional accuracy is better than 0.2 µ m. Second, the simulated heat deposition on the mask drastically decreases. In addition, simulation and experiment show good contrast of over 10 5 related to using a limiting aperture to intercept scattered electrons. As a result, this method is considered to be a key technology in future electron beam lithography systems.