Low resistance W-contact for 32-nm node devices and beyond

A 40% reduction in W-contact resistance compared to the 45-nm node process has been achieved by using both ALD-TiN treated with N₂ remote plasma and B₂H₆-reduced W-nucleation, and thus the resistance of a 32-nm node W-contact could be kept the same as that of the 45-nm node process despite the 70% shrinkage in the contact diameter. To further shrink devices, low-resistivity CVD-W film was fabricated by avoiding anomalous W-growth on quite thin nucleation by treating the surface of the W-nucleation layer.