Influence of the Elemental Composition on the Surface of the GaN Layer on the Surface Energy in Ammonia MBE

The paper presents the results of a study of the effect of the elemental composition on the surface of the GaN layer on its surface energy. It was found for the first time that formation of GaN quantum dots on the AlN surface can occur with an increase in the temperature of the GaN layer in the ammonia flow. An analysis of the chemical reactions taking place on the surface of the GaN layer was carried out, and the bare surface of GaN was also considered. Based on the chemical analysis performed, a particle was identified, namely hydrogen, whose intense desorption from the surface of the GaN layer leads to a decrease in the degree of filling of the uncompensated bonds of the bare GaN surface. Thus, a kinetic model of the 2D-3D transition was proposed, in which an increase in the surface energy of the 2D layer is associated with an increase in the degree of depletion of broken gallium bonds on the surface with hydrogen atoms.