Growth of adhesive cubic phase boron nitride films without argon ion bombardment

Previously, in situ bombardment of massive ions (Ar+, Kr+, etc.) was considered to be necessary for the formation of c-BN films. Because of the accumulated stress, bombardment of massive ions has led to the formation of c-BN films with poor adhesion. Here we show that c-BN films can be grown without involving bombardment of massive ions. This is achieved by using plasma-assisted pulsed-laser deposition (PLD) in pure N2 RF plasma. Furthermore, we show that c-BN films can be grown in a vacuum (∼10− 5 mbar during growth) by PLD without auxiliary ion source. We show that these are possible at a reduced deposition rate. Energetic growth species initiated by PLD and the pure N2 plasma is sufficient to form adhesive c-BN films at moderate deposition rate as long as the energy transfer rate per growth species is sufficient.