Possibility of AlN growth using Li–Al–N solvent

The possibility of AlN growth using LiAlN solvent was investigated. Based on theoretical prediction, we selected Li₃N as a suitable nitrogen source for AlN growth. First, vapor phase epitaxy using Li₃N and Al as source materials was performed to confirm the following reaction on the growth surface: Li₃NAl=AlN3Li. The results suggest that the reaction proceeds to form AlN on the substrate under appropriate conditions. Next, AlN growth using LiAlN solvent was carried out. The LiAlN solvent was prepared by annealing of mixtures composed of Li₃N and Al. The results imply that AlN was formed under an Al-rich condition. Moreover, it was found that Li was swept out from AlN grains during growth. The results suggest that AlN growth using LiAlN solvent might be a key technology to obtain an AlN crystal boule.