Effects of substrate negative bias voltages on preferred orientation and surface morphology of CrN films deposited by DC reactive magnetron sputtering

CrN films were prepared under different substrate negative bias voltages by DC magnetron sputtering. The preferred orientation, composition and surface morphology were explored by X-ray diffraction, EDS and SEM, respectively. The mechanism of bias voltages was also discussed. The results showed that the variation of bias voltages did not affect the phase composition of CrN films. However, when Ar and N2 flux were 6 and 30ml/min respectively, the preferred growth of CrN films changed from (111) to (200), then no clear preferred growth with the increase of bias voltages from -50 to -225V. In addition, as negative bias voltages increased, surface morphology of CrN films also changed from irregular shape with angular structure to globular structure gradually and the grain size decreased.