Magnetic field emission gun with zirconiated emitter.
A magnetic-field-superimposed field emission gun with low aberrations and equipped with a zirconiated tungsten emitter has been developed for applications where very stable high probe currents are required. It has been tested on a conventional electron microscope at 10 kV and on an electron beam testing system at 1 kV. Probe current i = 250 nA in a probe size d = 0.4 micron is obtained at 10 kV; at 1 kV the resolution is 0.1 micron with i = 5 nA, and 0.4 micron with i = 30 nA. For these probe currents, the spatial broadening effect due to electron-electron interactions in the beam is the preponderant factor limiting the probe size.
Troyon
M
M
UFR Sciences, Laboratoire de Microscopie Electronique, U 314 INSERM, Reims, France.
D008280:Magnetics; D008433:Mathematics; D008854:Microscopy, Electron / Q000295:instrumentation*; D015040:Zirconium
D015040:Zirconium