Cubic boron nitride (c-BN) films have been prepared by tuned substrate RF magnetron sputtering with different deposition times. The films have been characterised by Fourier Transform Infrared Absorption (FTIR) spectroscopy, X-ray Photoelectron Spectroscopy (XPS) and by Atomic Force Microscopy (AFM) measurements. The results show changes in composition and microstructure of the films with different deposition times that correspond to different growth stages of the BN films. By analysing the AFM images, we believe the BN layer formed at the early stages of deposition have a hillock morphology.