3D-Printed, Non-Planar Electron Sources For Next-Generation Electron Projection Lithography

We report the first non-planar electron sources for electron projection lithography (EPL). Fabricated by 3D printing, the devices deliver confocal emission, achieving focusing and demagnification without needing electrostatic lenses. Emission is produced by a concave dish base with an array of carbon nanotube (CNT)-coated emitters aligned to the apertures of a concave extractor electrode; both are fabricated by vat photopolymerization 3D printing and modified by subsequent coatings. Our prototype device exhibits a startup voltage of 500 V, a peak emission current of 300 μA/cm2, and a field enhancement factor of 7.8×104 cm-1. Phosphor screen imaging of the devices in operation demonstrates that the emission is spatially uniform. This revolutionary paradigm enables compact design at industrially required emission specifications of next-generation lithography systems.