Stable Electron Emission from Graphite-Nanoneedles and Their Application to Scanning Electron Microscopes

Abstract

The authors demonstrate both the stable and high brightness field emission from graphite nanoneedle (GRANN) cathode fabricated by simple plasma etching of a graphite rod. Bright electron emission of the order of 1012 Asr-1m-2) is obtained from GRANN cathode. As well as the bright emission, a stable emission under high residual pressure (10-5 torr) is obtained by lightly heating the GRANN cathode (Thermal-FE operation). The performance of the GRANN cathode is demonstrated by the construction of an FE scanning electron microscope (SEM) with the GRANN cathode and clear FE-SEM images are obtained at high residual pressure of the order of 10-5 torr