A VERY LOW ENERGY ELECTRON COLUMN FOR SURFACE STUDIES

摘要

We report on the development of a small size (9 cm in length and 4.5 in diameter) all electrostatic field emission column for use in surface analysis and very low energy studies. The column focuses a beam of electrons over the energy range 1-10,000 eV through the use of the cathode lens mode. The cathode lens mode employs an in-lens electron detector, which is placed between the gun lens and the objective lens. An electron beam diameter of 80 nm and beam current of order 10~(-9)A are predicted for a working distance of 5 mm and electron beam energy of 5 keV. When the column is operated in the cathode lens mode, an electron beam diameter <250 nm at 10 eV is expected.