The nucleation of diamond on silicon (100) in a methane-in-hydrogen microwave plasma has been investigated by atomic force microscopy (AFM), scanning electron microscopy (SEM), and reflection high energy electron diffraction (RHEED). The nucleation of diamond was performed by application of an electrical substrate potential. It was found that three-dimensional non-facetted islands are initially formed whose sizes increase with the deposition time. In spite of their very small sizes of a few nanometers, RHEED reveals that the islands are of crystalline diamond structure. An induction time of about 6.5 min was necessary for the diamond nucleation, which is partly caused by the formation of a silicon carbide surface layer due to the carbon diffusion into the substrates. The time dependence of nucleation density was investigated and fitted with a model kinetics which considers the formation, destruction, and capture of active sites, germs, and nuclei. Analyses of the first nearest neighbor distance distributions reveal the formation of a depletion zone of nuclei around the existing islands. These results confirm the role of the adatom diffusion improved by the bias-enhanced ion bombardment. Analyses of the island size and the island height distributions show constant growth rate at beginning of the diamond deposition. From the nearly constant ratios of the island height to island size, independent of the nucleation time, one can deduce that the thermodynamics accounts not only for the growth mode, but also for the island shape during deposition. The bias-enhanced ion bombardment during deposition may increase also the diffusion of the surface atoms of the islands, allowing the system to approach equilibrium

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Electron-beam deposition in a f'eld-edssion electron microscope :s used to grow nigh aspect rat:o carbon contam'nat:on tips su:table f o r imaging in atomic force microscopy. Tip lengths of up to several microns, t p diameters between 100 ano 400 nm an0 cone half-angles of 3°-.50" are actieveo with typical raoii o f c"ture between 20 and 40 nm. The influence of the major depos:tion parameters, i.e. electron energy, beam current, deposition time and working distance, on the growth rate and shape (length, cone angle and cone length) d the t'p, are 'nvest'gated systematically. It is found that increasing beam cJrrent leads to a decrease in length growth probably due to enhanced thermal desorption of adsorbates and redJCed sticking coefficients. Electron energy ma'nly determ'nes cone angles and cone length wh'e the variation of working d'stance only has a small influence on the tip growth. Imaging capabi1:ties d the t'ps are verified on vert:caily wa eo, lithographically fabrcated panerns

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