Field emission characteristics of a graphite nanoneedle cathode and its application to scanning electron microscopy

Abstract

A high-brightness electron beam of more than 1011 A sr-1 m-2 was achieved from a graphite nanoneedle cathode, which was fabricated by simple hydrogen plasma etching of a graphite rod. A field emission was obtained at a high residual pressure of 10-6 Torr. The performance of this cold cathode was demonstrated by the fabrication of a scanning electron microscope, which was operated at a high residual pressure of 10-5 - 10-6 Torr. The brightness of this cathode offers a convenient field electron emission source that does not require a massive ultrahigh vacuum system. © 2006 American Institute of Physics.