Interconnect issues post 45nm

Despite many projections on the inevitable post-PVD evolution of interconnect technology, it remains PVD-based for liner-seed through 45 nm and perhaps farther, with an ALD process change the obvious next step perhaps followed by a switch from Ta to Ru. Cu size effects are not critical to low-level (1times) line RC and the biggest performance opportunity is with the high level fat lines. CA technology, both barrier and fill, does not scale well and may evolve to more interconnect-like materials, potentially unifying two tooling areas