Reduced resistivity of NiAl by backthinning for advanced interconnect metallization

Abstract

NiAl lias been investigated as a potential alternative for Cu in future interconnect metallization schemes. Backthinning experiments of thick NiAl films (> 50 nm) by IBE or CMP leads to large grain sizes for small thicknesses. NiAl deposited at 420°C by PVD shows a resistivity of 17 μΩcm for a 10 nm NiAl film. Combining deposition of epitaxial NiAl on Ge (100) with backthinning experiments using CMP led to a lower resistivity than PVD Ru: 11.5 μΩcm at 7.7 nm and 10.6μΩcm at 17.2 nm.