In situ post etching treatment as a solution to improve defect density for porous low-k integration using metallic hard masks

H 2 , O 2 , NH 3 and CH 4 in situ post-etching treatments (PET) have been investigated as a solution to prevent the residues formation (TiFx based) on TiN metallic hard mask (MHM) after etching in fluorocarbon based plasmas. The PET impact on the residues growth reduction on the mask and on the porous SiOCH modification is presented and discussed. The compatibility of the different PET is also evaluated for C045 dual damascene level using trench first MHM integration.