Construction of STM Aligned Electron Field Emission Source

We constructed a scanning tunneling microscope aligned field emission (SAFE) source by using silicon micro-fabricated electrostatic lenses. The system consists of an STM aligned field emitter, 5μm extractor, 100μm accelerator, beam dump, quadrupole deflector and einzel lens. The microlenses were made by using silicon processing techniques. The system can be operated from 200 to 2 kV, resulting in a beam current of tens of nA and with the diameter of ∼ 0.1 μm when a sample was placed less than 2 mm away from the exiting einzel lens. In order to measure the spherical and chromatic aberrations, a detector and cylindrical electron energy analyzer were attached to the micro-column.