Effect of the Arsenic Concentration on the Characteristics of the Growth Step Echelon in GaAs Epitaxy

The effect of the arsenic concentration in the vapor phase on the growth step distribution over the surface of GaAs epitaxial layers grown in a chlorine-hydride vapor-transport system on substrates with 4° (111)A and (113)A orientations is studied. It is demonstrated that the average distance between steps in the echelon depends on the arsenic concentration and increases with it up to a certain constant value. It is assumed that this is connected with the change in the kink density at the steps.     

Interaction of Growth Steps on the Surface of InAs Epitaxial Layers in Vapor-Phase Epitaxy

The influence of concentrations of vapor-phase growth components on the structure of singular, vicinal, and nonsingular growth surfaces of InAs epitaxial layers grown in the In–AsCl₃–H₂ system is investigated by the methods of electron microscopy. It is established that the average distance between steps in the echelon increases as the input pressure P _AsCl3 increases in the range 70–700 Pa and then approaches a constant value when P _AsCl3 > 700 Pa. The observed dependences (P _AsCl3) are explained within the framework of the model of diffusion interaction of steps.