Possibility of AlN growth using Li–Al–N solvent

The possibility of AlN growth using Li–Al–N 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: Li3N+Al=AlN+3Li. The results suggest that the reaction proceeds to form AlN on the substrate under appropriate conditions. Next, AlN growth using Li–Al–N solvent was carried out. The Li–Al–N 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 Li–Al–N solvent might be a key technology to obtain an AlN crystal boule.