Low k damage control & its reliability for organic hybrid dual damascene

A hybrid dual damascene interconnect approach with organic ultra-low-k for gap filling has been demonstrated. The traditional PR approach with via-first process for dual damascene suffers from ashing damage for CVD ultra-low-k. Our approach is able to circumvent the issues mentioned above without introducing process complication. Good sheet resistance control is obtained for trench etch without a middle stop layer. And good via resistance yield with good thermal stability is obtained as well. 21% of RC product reduction is obtained when it is compared with the PR approach for CVD ultra-low-k.