Study of arsenic flux effect on thermal desorption of GaAs native oxide and surface morphology

In this paper we presents the results of studying the molecular arsenic flux effect on the processes of native oxide thermal desorption and the resulting surface morphology of GaAs(001) substrates. We have shown that the exposure of GaAs under As flux at the stage of oxide removal significantly modulates the decomposition of native oxide and its chemical interaction with substrate materials. Based on the obtained experimental results and analysis of possible chemical reaction in this system we have shown that in the presence of arsenic molecules on the surface, free gallium atoms bind with it and no longer participate in the decomposition of native oxide components. This leads to additional decomposition of the substrate materials as a result of its etching. As a result, nanoholes of lower density, but larger in size, are formed on the surface. We have also shown that a decrease in the oxide thickness leads to a decrease in the density and dimensions of the nanoholes.