Various procedures, such as using a buffer layer or multi-growth mode modification, were
investigated for the growth of AlN layers on sapphire substrate at high temperatures by
metalorganic vapor phase epitaxy. Even though the top AlN layers were grown under the
same conditions, the each crystalline quality was different. There is a clear relationship
between the strain during growth and the quality of AlN films. AlN grown under the least
strain shows the highest quality. Furthermore, it was found that cracks were suppressed by …