IITC 2018
Conference paper

Modified ALD TaN Barrier with Ru Liner and Dynamic Cu Reflow for 36nm Pitch Interconnect Integration

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Integration of thermal atomic layer deposition (ALD) TaN films modified by physical vapor deposition post-treatment (PPT) and in-situ plasma treatment (IPT) was investigated on 36nm pitch BEOL structures. The PPT and IPT processes produce an interface more suitable for liner (Co/Ru) and physical vapor deposition (PVD) of Cu seed. This results in improvement in Cu gap-fill for both traditional Cu seed/plating process with 15 Å chemical vapor deposition (CVD) Co liner and dynamic PVD Cu reflow (DCR) on 20 Å CVD Ru liner. The PPT also decreased via resistance (R) by sputtering TaN at bottom of the via. IPT processes densify the ALD films and improve EM performance. A promising integration scheme of 20 Å ALD+IPT TaN/20Å Ru/DCR was developed with 20X improvement in electromigration.