Ion beam fabrication of diamond probes for a scanning tunneling microscope

Abstract

Ion beam fabrication methods combined with mechanical lapping and ion beam dynamic mixing have been developed to obtain diamond probes for a scanning tunneling microscope. Diamond styli for a surface profilometer were sharpened to a tip radius of approximately 10 nm using a Kaufman-type ion beam machining apparatus and were then coated with gold or platinum film by ion beam dynamic mixing in order to increase the electrical conductivity of the probe surface. The sharpened styli can be used as probes to obtain atomic STM images of HOPG (highly ordered pyrolytic graphite) in ambient air. Moreover, diamond probes coated with a gold or platinum film after ion beam sharpening can also be used to obtain atomic STM images of HOPG and topographical STM images of a steel gauge block coated with gold film in ambient air.