Determination of In-Ga-As phase diagram at 650 °C and LPE growth of lattice-matched In0.53Ga0.47As on InP

The liquidus isotherm in the In-rich corner of the In-Ga-As system at 650 °C was experimentally determined by an improved seed dissolution technique using InP seeds. The solidus isotherms at this temperature were also determined in the composition range close to lattice-matched In0.53Ga0.47As on InP. The solidus data are strongly affected by the crystallographic orientation of the substrate, but are not significantly affected by the degree of lattice matching. The calculated phase diagrams have been compared with the experimental results. The conditions for equilibrium LPE growth of exactly lattice-matched ternary layers on InP (100) and (111) B substrates were obtained from the results of the phase diagram and lattice-constant measurements. It was found that the distribution coefficient, growth rate, and surface morphology are strongly dependent on the substrate orientation. The distribution coefficient for Ga and the growth rate at 650 °C are both larger on the (100) face than on the (111) B face. Hillocks often appear on the (111) B face irrespective of degree of lattice matching, but rarely appear on the (100) face.