Patent ID: 8764994
Filing Date: 2014-07-01
Classification: H01J

Abstract:
1. A method for fabricating a sharpened needle-like emitter, the method comprising: electrolytically polishing an end portion of an electrically conductive emitter material so as to be tapered toward a tip portion thereof; performing a first etching in which the electrolytically polished part of the emitter material is irradiated with a charged-particle beam to form a pyramid-like sharpened part having a vertex including the tip portion; performing a second etching in which the tip portion of the sharpened part is further sharpened through field-assisted gas etching, while observing a crystal structure at the tip portion of the sharpened part by a field ion microscope and keeping the number of atoms at a leading edge of the tip portion of the sharpened part at a predetermined number or less; and heating the emitter material to arrange the atoms at the leading edge of the tip portion of the sharpened part in a pyramid shape.