Production method for a low-dislocation bulk aln single crystal and low-dislocation monocrystalline aln substrate

Abstract

A bulk AlN single crystal is grown on a monocrystalline AlN seed crystal having a central longitudinal mid-axis and disposed in a crystal growth region of a growing crucible. The bulk AlN single crystal grows in a growth direction oriented parallel to the longitudinal mid-axis by deposition on the AlN seed crystal. The crucible has a lateral crucible inner wall extending in the growth direction, a free space being provided between the AlN seed crystal and the growing bulk AlN single crystal on the one hand, and the lateral crucible inner wall on the other hand. Bulk AlN single crystals and monocrystalline AlN substrates produced therefrom are therefore obtained with only few dislocations, which furthermore are substantially distributed homogeneously. The growing crucible, inside which the crystal growth region is located, is an inner growing crucible which is arranged in an outer growing crucible. The two growing crucibles are provided with a crucible lid with a gap formed between the inner growing crucible and the crucible lid through which some of the AlN growth gas phase generated inside the crystal growth region escapes and is deposited on a crucible bottom of the outer growing crucible which lies opposite the crucible lid.