Vapor-phase epitaxy of AlN layers on AlN/Si(111) templates synthesized by reactive magnetron sputtering

Epitaxial aluminum nitride (AlN) layers on Si(111) substrates have been grown by sequential application of several techniques including reactive magnetron sputter deposition to a thickness of 20 nm, metalorganic vapor-phase epitaxy (MOVPE) to a total thickness of 450 nm, and hydride vapor-phase epitaxy (HVPE) to a final thickness of 2 $\mu$m. Synthesis of AlN layers by this combined method provides a significant decrease in the residual strain and suppresses the formation of cracks in the epilayer.