PHYSICAL CHARACTERIZATION OF DIAMOND PYRAMIDAL MICROTIP EMITTERS

Micropatterned diamond pyramidal tips have been demonstrated to have h igh emission current. This article presents in great detail the physic al characterizations that have proceeded to characterize the topology, morphology, and microstructure of these diamond microtips using trans mission electron microscopy (TEM), atomic force microscopy (AFM), scan ning tunneling microscopy (STM), and Raman spectroscopy. The results s how that the diamond microtips are indeed a polycrystalline diamond st ructure as evidenced by Raman spectroscopy and diffraction analysis of the TEM. AFM and STM results provide detail information as to the sur face and tip shape of the diamond emitters. AFM/STM observations sugge st a nucleation and growth process whereby the matter in which chemica l 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 diamon d microstructure in the field area with that of the tip where distinct differences are observed. (C) 1997 American Vacuum Society.