High-current electron optical design for reflective electron beam lithography direct write lithography

The authors present the latest design and results for the second generation column used in the reflective electron beam lithography program. The previous magnetic prism based concept to separate the illumination and projection beams has been replaced with a Wien filter that allows the column to be shrunk in size by a factor of 3, resulting in reduced Coulomb blur and energy spread. Experimental data from the column are presented and compared to simulation. The authors also discuss design considerations for this and future columns, including beam voltage, numerical aperture selection, and cathode optimization.