Tomohito Matsuo

Electron wave interference induced by electrons emitted from Pt field emitter fabricated by focused-ion-beam-induced deposition

Fringelike electron emission patterns emitted from Pt field emitters fabricated by focused-ion-beam-induced deposition (FIBID) were investigated by field-emission microscopy and in situ field-ion microscopy (FIM). The FIM image with electron emission sites showed adjacent two emission sites within a diameter of a Pt nanocrystal. These results indicate that the origin of fringelike electron emission patterns of Pt field emitters fabricated by FIBID are the electron wave interference induced by electrons emitted from adjacent two electron emission sites within a Pt nanocrystal.

11.2: Electron emission properties of coherent field emitter for electron wave interference

The current-voltage curves of the Pt field emitters with interference patterns showed the saturation at higher applied voltage. The slope of the FN plots is also flattened at higher applied voltage. The reason for the flattened FN plots might be due to the finite reflection of ballistic electrons, when the energy barrier between the emitter and vacuum becomes lower than the Fermi energy under strong electric fields. These results indicated that the electron wave interference might take place by ballistic electrons emitted from the Pt field emitters

Electron-wave interference induced by electrons emitted from Pt field emitter fabricated by focused-ion-beam-induced deposition

The development of a coherent-field emitter for electron-wave interferences and its possible application have been investigated in our research. So far, electron-wave interferences induced by electrons emitted from a Pt field emitter fabricated by electron-beam-induced deposition (EBID) were reported.1,2 However, the field emission properties and electron-emission patterns of Pt field emitters fabricated by focused-ion beam (FIB)-induced deposition (FIBID) have not been characterized. The resistivity of a Pt nanowire fabricated by EBID was quite high and decreases by three to four orders of magnitude after annealing at 400° C.3,4 On the other hand, the resistivity of Pt nanowire deposited by FIB was very low even without annealing. The Pt field emitter fabricated by FIBID might be, therefore, more suited to the coherent-field emitter. In this study, the characteristics of Pt field emitters fabricated by FIBID and their electron-emission patterns of electron-wave interference were investigated.