DECREASE OF DISLOCATIONS IN GAAS BY ISOELECTRONIC DOPING OF LIQUID-PHASE EPITAXIAL LAYERS

InxGa1-x,As layers were grown on (100) GaAs substrates by use of isoel ectronic doping of liquid phase epitaxial layers under optimal growth conditions. The dislocations in the GaAs substrate and the InxGa1-xAs epitaxial layer were revealed simultaneously by ultrasonic etching in CrO3-HF aqueous solutions. The dislocation density in the epitaxial la yer was decreased by a factor of 20 compared with that in the substrat e. An experimental based formula, which calculates the confining proba bility and the model of the combining network of dislocations growing into the epitaxial layer from the substrate, is also given. It is dedu ced that the optimal doping level of In occurs at x = 0.04 or 0.05.