A field emission scanning electron microscope (FESEM) uses a focussed and scanned electron beam to produce a magnified image of a sample surface. The FESEM comprises an electron gun, a lens system, scanning coils, an electron collector, and a cathode ray display tube. The electron gun in a field emission SEM operates on the field emission principle and has a better resolution than the standard tungsten filament electron gun.
A Jeol JSM 7500F FESEM is available, which has a resolution of 1nm at 15kV, can operate between 0.5 and 30kV and the magnification can be varied from '100 to '1,000,000. The Jeol FESEM is primarily used as an in-line tool to image wafers after electron-beam lithography and etch. A field emission scanning electron microscope is also available as part of the Zeiss NVision40 focussed ion beam system. This FESEM has a resolution of 1.1nm at 20kV and is primarily used for sample characterisation on completion of fabrication.
