Controlled focused electron beam-induced etching for the fabrication of sub-beam-size nanoholes

Sub-beam-size focused electron beam-induced etching of amorphous carbon membranes was achieved. The size of the tungsten filament generated electron beam was determined from the in situ stage current monitoring and verified by knife edge measurements. The in situ time resolved stage current measurements as an end point detection allowed the fabrication of nanoholes with a diameter of sub-20nm, corresponding to 20%–40% of the full width at half maximum of the incident beam.