High-density silicon and silicon nitride cones

High-density cone-shaped silicon and silicon nitride have been synthesized on Si(1 0 0) substrates via plasma-assisted hot-filament chemical vapor dep osition using a gas mixture of nitrogen, hydrogen and methane. Aligned sili con cones containing 3-10 at % C and N have been formed with less than 1 h growth. Further growth can lead to the increase of cone size and density, a s well as to the formation of polycrystalline silicon nitride films on the tip and surface. The formation of these materials is thought to be due to t he remodification of Si substrates under the effect of plasma and active C and N species. Different nucleation and growth styles were obtained under d ifferent growth conditions and reactive gas mixtures, (C) 2000 Elsevier Sci ence B.V. All rights reserved.