Phase equilibria in In-Metal-As systems: Systematic trends in phase diagram topology and implications for the development of contact materials to InAs

Abstract

Isothermal phase equilibria are established in the InAs-rich regions of 16 In-M-As ternary systems, where “M” denotes a transition or noble metal. These new data, combined with work previously reported in the literature, provide a nearly complete picture of phase equilibria in In-M-As systems. The topologies of the In-M-As phase diagrams are found to vary systematically according to the position of M in the periodic table. This correlation may be rationalized using experimental thermodynamic data found in the literature, and reflects a systematic dependency of the relative thermodynamic stabilities of transition and noble metal indides and arsenides on atomic number of the metal. These phase diagram data are also utilized to select materials that are suitable as contact metallizations to InAs. Based on the criteria of thermodynamic equilibrium, ease of fabrication, and high melting point, W, Re, Os, RhIn3, PdIn and PtIn2 are identified as the most promising potential contact materials to InAs.