Investigations of crystallinity and residual stress of cubic boron nitride films by Raman spectroscopy

With a spatial correlation model, a simple method was established to evaluate the crystallinity and stress of cubic boron nitride (cBN) films from the variation of linewidth and peak shift of Raman spectra. An increase of crystallinity and a decrease of stress of the cBN films with growth time were demonstrated. As a reference, the Raman spectra of cBN single crystals synthesized by a high-pressure, high-temperature method were also investigated. Our cBN film deposited for 1 h revealed a low stress of about 1 GPa and a comparable crystallinity to that of 4-8 μm commercially available cBN single crystals.