Integration of a k=2.3 spin-on polymer for the sub-28nm technology node using EUV lithography

In this work we integrate an advanced k=2.3 spin-on polymer at 40nm ½ pitch. K-value restoration techniques are investigated and complete k-value restoration is demonstrated using an in-situ HeH₂ plasma. An EUV compatible stack and a dielectric dual hard mask scheme is developed to pattern trenches with good uniformity and low litho-etch bias. The impact of scaling the dielectric spacing and of direct CMP on time dependent dielectric breakdown is also studied.