Condensed phase equilibria in transition metal–In–Sb systems and predictions for thermally stable contacts to InSb

Abstract

InSb is useful for a wide variety of devices including infrared detectors, imaging systems and high-speed electronic devices. However, very little work has been done to address the issue of contact metallurgy for InSb. To assist with the design of shallow and/or thermally stable contacts to InSb, we have performed thermodynamic calculations to estimate ternary phase diagrams for many of the transition metal–In–Sb systems. Similar phase diagrams have been valuable tools in the development of contacts to other III–V semiconductors. We present the results of our estimates of the phase equilibria in transition metal–In–Sb systems for which no diagrams were previously available, describing the necessary approximations we made. We have categorized these phase diagrams according to the dominant features in their tie-line configurations to highlight trends in the contact metallurgy across the periodic table. For comparison, we have also applied the same method for estimating phase diagrams in the Ni–, Pd– and Au–In–Sb systems, for which some experimental work has already been reported. Very good agreement was found between the types of tie-line configurations predicted and those reported from experiments. According to our calculations, Cr, Mo, W, Re, Fe, Ru and Os are the transition metals anticipated to be in thermodynamic equilibrium with InSb under the conditions considered in our calculations.