Growth of bulk AlN crystals by vapor-phase epitaxy from atomic Al and NH$_3$

A new approach to obtaining bulk AlN single crystals by vapor-phase epitaxy has been tested. NH$_3$ and Al vapor were used as growth reagents. The following ranges of growth parameters were admissible for the laboratory equipment (experimental growth installation): temperatures of 1050–1500$^\circ$C at ammonia flow rates of up to 50 sccm and pressures on the order of 10$^{-5}$–10$^{-4}$ bar, growth rates of up to 200 $\mu$m h$^{-1}$. At a temperature of 1450$^\circ$C, samples of strained bulk block AlN crystals with thicknesses of up to 200 $\mu$m were obtained in the wurtzite phase in the [0001] direction on MBE templates based on sapphire substrates with a diameter of 2".