Ab initio screening of metallic MAX ceramics for advanced interconnect applications

The potential of a wide range of layered ternary carbide and nitride Mn+1AXn [an early transition metal (M), an element of columns 13 or 14 of the periodic table (A), and either C or N (X)] phases as conductors in interconnect metal lines in advanced complementary metal-oxide-semiconductor (CMOS) technology nodes has been evaluated using automated first-principles simulations based on density-functional theory. The resistivity scaling potential of these compounds, i.e., the expected sensitivity of their resistivity to reduced line dimensions, has been benchmarked against Cu and Ru by evaluating their transport properties within a semiclassical transport formalism. In addition, their cohesive energy has been assessed as a proxy for the resistance against electromigration and the need for diffusion barriers. The results indicate that numerous MAX phases show promise as conductors in interconnects of advanced CMOS technology nodes.