Features of molecular beam epitaxy of the GaN (0001) and GaN (000$$ \bar 1 $$) layers with the use of different methods of activation of nitrogen

The results of comparative studies of the growth kinetics of the GaN layers of different polarity during ammonia molecular beam epitaxy and plasma-assisted molecular beam epitaxy (PA MBE) of nitrogen with the use of sapphire substrates and GaN(000\(\bar 1\))/c-Al₂O₃ templates grown by gas-phase epitaxy from metalorganic compounds are presented. The possibility is shown of obtaining the GaN layers with an atomically smooth surface during molecular beam epitaxy with plasma activation of nitrogen. For this purpose, it is suggested to carry out the growth in conditions enriched with metal near the mode of formation of the Ga drops at a temperature close to the decomposition temperature of GaN (TS ≈ 760°C). The conclusion is made that an increase in the growth temperature positively affects the structural, optical, and electrical properties of the GaN (000\(\bar 1\)) layers. A high quality of the GaN (0001) films grown by the PA MBE method at a low temperature of ～700°C on the GaN/c-Al₂O₃ templates is shown.