Nonequivalent atomic step edges—Role of gallium and nitrogen atoms in the growth of InGaN layers

In this work we study the peculiar role of gallium and nitrogen atoms in the growth of InGaN by Plasma Assisted Molecular Beam Epitaxy (PAMBE). We investigate growth of InGaN layers on vicinal GaN (0001) substrates. Indium incorporation as a function of gallium and nitrogen fluxes was examined. We propose a microscopic model of InGaN growth by PAMBE postulating different indium adatom incorporation mechanisms on two nonequivalent atomic step edges of wurtzite crystal. The role of gallium and nitrogen fluxes during the growth of InGaN layers is discussed.

► Indium incorporation limits in plasma assisted molecular beam epitaxy.
► Phenomenological model of In incorporation into InGaN layers.
► InGaN morphology affected by presence of non-equivalent atomic step edges.
► The role of nitrogen flux in the growth of high indium content InGaN.