Directional Etching of Barrierless NiAl Lines on 300-mm Wafers for Interconnects Applications

This letter demonstrates the functionality of barrier-less 20nm NiAl for 100nm metal pitch interconnects fabricated on 300mm full wafers. We have developed an industry-relevant integration route consisting of a SiN hard mask patterned by reactive ion etching and directional NiAl etching by ion beam etch techniques. The resistivity for NiAl is found to be close to Ru, along with 99% electrical yield, impressive uniformity across the full wafer, and no bridging or line collapsing was observed.