Formation of fibrous structures on diamond by hydrogen plasma treatment under DC bias

Diamond films and powders were treated in microwave plasma of hydrogen at 1 .6 torr under a negative DC bias of 200 V for 3-6 It. As a result, a fibrou s structure was formed on the diamond surface along the direction normal to the surface, while diamond was simultaneously etched at a rate of approxim ately 1 mum/h. For a 3-h processing, the fiber diameter near the top end wa s less than or equal to 50 nm and the fiber lengths were 2-3 mum. Transmiss ion electron microscopy (TEM) indicated that the fibers consisted of random ly oriented nanocrystals with diameters of < 10 nm. The lattice spacings in the nanocrystals, obtained from TEM images, were 0.22 and 0.25 nm, and hen ce the structures were assigned to a strongly distorted diamond. An overgro wth of diamond on the fibrous structure resulted in an almost uniform coati ng of the fibers with crystal-faceted diamond. (C) 2001 Elsevier Science B. V. All rights reserved.