Formation of crystalline diamond by ion beam deposition

Abstract

Direct ion beam deposition was used to study the effect of ion bombardment on the formation of carbon films. Amorphous carbon films were deposited on mirror-polished (0 0 1) silicon substrates by means of a low-energy ion beam of Ar/H 2/CH 4. High-resolution transmission electron microscopy, field emission scanning electron microscopy and micro-Raman microscopy were used to determine some of the properties of the samples. We found that the amorphous carbon film condensed to form clusters and the surface roughness of the film increased with increasing the ion dose. At ion doses ∼10 19/cm 2, crystalline diamond particles with sizes of 15–30 nm were formed in the matrix of amorphous carbon films. The formation of crystalline diamond particles may be due to the ion bombardment induced stress and energy fluctuation.