Design of an ultra-miniaturized electron optical microcolumn with sub-5 nm very high resolution

The achievement of a microminiaturized electrostatic electron optical column with very-high-resolution probe beam is an important challenge in the fields of electron beam lithography, metrology, and inspection for semiconductor and/or display devices. In this study, we propose an ultra-miniaturized, very-high-resolution electron optical microcolumn that can be assembled more easily compared to previous structures. The design mitigates the complexity of conventional manufacturing processes by eliminating the einzel lens without affecting the resolution performance. According to our numerical simulation results, the proposed ultra-miniaturized electron optical microcolumn produces superior performance with respect to probe beam size and deflection field size as compared to previously published results. A very high, sub-5-nm-resolution probe beam size and a deflection field size larger than 60 μm are achievable at the electron energy of 1 keV and a working distance of 1 mm by inserting a focusing electrode and removing the einzel lens.