Mechanism of defects formation and surface smoothening of AlN films grown on Si(111) by an NH3 pulsed-flow method

In this paper, we investigate the growth of AlN films on Si (111) substrate by an NH3 pulsed-flow method. Compared with AlN films grown with a continuous NH3 flow, the AlN films grown by the pulsed NH3 flow method shows a smoother surface, and quasi-two-dimensional growth is achieved. But the (0002) and (10−12) FWHM show that the crystal quality of AlN films grown by the NH3 pulsed-flow method is slightly deteriorated, indicating that more defects are formed. The defects formation and surface smoothening mechanisms are discussed.