Phase equilibria in the system In-Ir-As at 600 °C

Phase equilibria were established in the In-Ir-As system at 600 °C using X-ray diffraction and electron probe microanalysis. InAs was shown to be in thermodynamic equilibrium with indium, IrAs₃, and IrAs₂. Owing to undesirable intrinsic properties, none of these phases is suitable as a contact material to InAs or to compound semiconductor alloys containing InAs as a constituent. However, a quaternary Ga-In-Ir-As phase diagram sample showed that Ir₃Ga₅ was in thermodynamic equilibrium with the solid solution In_xGa_1-xAs from x = 0 to at least x = 0.55. Therefore, Ir₃Ga₅ could be used as a thermodynamically stable contact material to In_0.53Ga_0.47As, one of the most technologically important compositions of the In_xGa_1-xAs semiconductor alloy.