Formation of cubic boron nitride films by r.f. magnetron sputtering

Boron nitride thin films have been deposited on silicon by tuned substrate r.f. magnetron sputtering from a sintered hexagonal BN target using a mixture of Ar (90%) and N2 (10%) as sputtering gas at different substrate bias conditions. The deposited films have been characterized by Fourier transform infrared spectroscopy (FTIR) and x-ray photoelectron spectroscopy (XPS). Both FTIR and XPS results show that the formation of nearly pure cubic boron nitride films were achieved when the films were deposited by a two-step process at a lower substrate bias voltage after the initial formation of the cubic boron nitride layer. Also, as indicated by FTIR measurements, this two-step process caused a reduction of the residual stress in the deposited films and no re-sputtering effects were present during the cubic BN growing process