Etch process development for FLARE/sup TM/ for dual damascene architecture using a N/sub 2//O/sub 2/ plasma

In this article, the feasibility of via and trench etch of FLARE/sup TM/, a low-k organic material product from AlliedSignal Inc. in dual damascene architectures for 0.25 /spl mu/m applications is described. The effects of O/sub 2/ concentration and flow rate on the etch rate and the etch profile of FLARE/sup TM/ during etching in oxygen reactive ion etch plasmas have been studied. Best via and trench profiles are obtained for a 25/5 nitrogen-to-oxygen ratio; no undercut of the hard mask is observed at a good etch rate. The feasibility of via filling with a low temperature W process and Cu fill of the trenches in a damascene structure has been demonstrated.