DIAMOND FILM ORIENTATION BY ION-BOMBARDMENT DURING DEPOSITION

The influence of ion bombardment during microwave plasma chemical vapo r deposition (CVD) on diamond film orientation has been investigated. Two interesting findings were obtained: (1) The [001] axes of the grow n diamond grains are always along the ion flow direction, perpendicula r-to the substrate and independent of the crystal orientation of the s ubstrates and (2) for the crystallites which are homoepitaxially grown on the (001) diamond faces parallel to the substrate slight misorient ations were found. These new findings confirm the role of ion impact i n diamond CVD and can help us to understand the basic mechanism respon sible for the crystal orientation in heteroepitaxial diamond films pre pared using bias-enhanced nucleation. (C) 1996 American Institute of P hysics.