Observation of fringelike electron emission pattern from triode Pt nano electron source fabricated by electron-beam-induced deposition

Fringelike electron emission patterns from Pt nanocrystalline field emitters fabricated by electron beam induced deposition (EBID) were observed. The electron emission sites were, further, observed by field ion microscopy, showing adjacent two emission sites within a diameter of a Pt nanocrystal. These results indicate that the origin of the fringelike electron emission patterns of Pt field emitters fabricated by EBID are the electron wave interference induced by electrons emitted from adjacent two electron emission sites on a Pt nanocrystal. In this study, a Pt nano electron source with a triode structure that has a gate electrode in order to control the intensity of fringelike emission pattern with low gate voltage has been fabricated. Characteristics of Pt nano electron source were measured at room temperature in a chamber with a base vacuum of 10^-8 Pa. The emission current was observed at a gate voltage of 30 V and showed a linear dependence in Fowler-Nordheim plots. Electron wave interference patterns observed were in good agreement with a Fraunhofer diffraction model.