Physical characterization of diamond pyramidal microtip emitters

Micropatterned diamond pyramidal tips have been demonstrated to have high emission current. This article presents in great detail the physical characterizations that have proceeded to characterize the topology, morphology, and microstructure of these diamond microtips using transmission electron microscopy (TEM), atomic force microscopy (AFM), scanning tunneling microscopy (STM), and Raman spectroscopy. The results show that the diamond microtips are indeed a polycrystalline diamond structure as evidenced by Raman spectroscopy and diffraction analysis of the TEM. AFM and STM results provide detail information as to the surface and tip shape of the diamond emitters. AFM/STM observations suggest a nucleation and growth process whereby the matter in which chemical vapor deposition diamond nucleates on the planar top surface of the tip substrate is distinct and different from the way the diamond grows in the cavity ''mold.'' Likewise, the TEM results contrast the diamond microstructure in the field area with that of the tip where distinct differences are observed. (C) 1997 American Vacuum Society.