METHOD FOR FORMING DUAL DAMASCENE PATTERN TO PREVENT VIA FACETING PHENOMENON AND VIA BOWING PHENOMENON CAUSED BY DIFFERENCE OF VIA HOLE DENSITY AND AVOID INCREASE OF DIELECTRIC CONSTANT OF LOW-K INTERLAYER DIELECTRIC

摘要

A kind of purpose: method, it is used to form the increase that a dual damascene pattern is arranged to prevention channel discrete phenomenon and the channel bow phenomenon as caused by a difference of channel hole density and avoids the dielectric constant of a low-k layer insulation, by preventing low-k layer insulation and a lower interconnection from being exposed to the oxygen plasma for removing an organic bottom arc (anti-reflection coating). Construction: a diffusion barrier layer (12), a layer insulation (13) and a cap layers (14) are formed in a substrate (10), have and are connected with each other. The exposed portion of cap layers and layer insulation is etched to form access opening (16) by access opening etch process. Mononitride separator is formed in the side wall in through-hole hole. One organic bottom arc is formed in composite structure. The exposed portion of organic bottom arc, cap layers and layer insulation is etched by a predetermined depth and forms a bar ditch (19) by a trench etch process. Nitride spacer is removed. The diffusion barrier layer contacted with the bottom in through-hole hole is eliminated.