Journal of Vacuum Science & Technology B, Vol.20, No.1, 326-337, 2002
Microscopic characterization of electron field emission
We report on the functional capabilities of a scanning anode field emission microscope (SAFEM) which combined with a phosphor screen is used to investigate and correlate individual electron emission site characteristics of low threshold thin film electron emitters in the micrometer regime. Spatially recorded extraction voltage V(x,y) maps under constant emission current or emission current I(x,y) maps under constant anode voltage reveal spatially divergent emission properties on thin film emitters. The V(x,y) maps are used to derive the field enhancement 3(x,y) maps which give a better description of the thin film emission properties as compared to electric threshold fields which depends on anode-cathode geometry. Individual emission site current stability of thin film emitters can be investigated with the SAFEM, and a high-resolution field emission microscope to investigate the environmental stability of single carbon nanotubes mounted on filaments as a function of partial gas pressures and temperature.