Silicon oxynitride cap for fluorinated silicate glass film in intermetal dielectric semiconductor fabrication

摘要

A semiconductor device and method of forming a patterned conductive layer on a semiconductor substrate are provided so as to prevent fluorine substance outflow from a fluorinated silicate glass (FSG) layer thereon and simultaneously so as to suppress back reflection of light waves into a photoresist layer during photolithographic processing. The substrate is coated in turn with a conductive layer, a dielectric (e.g., silicon dioxide) liner, a FSG layer, a silicon oxynitride layer preventing fluorine substance outflow therethrough from the FSG layer and also forming an antireflective coating (ARC), and a photoresist layer. The photoresist layer is exposed and developed to uncover pattern portions of the underlying silicon oxynitride layer. The uncovered pattern portions of the silicon oxynitride ARC layer and corresponding underlying portions of the FSG layer and dielectric liner are then removed, e.g., by,a single dry etching step, to expose pattern portions of the conductive layer for metallization. Upon metallization, the substrate is provided with a combination of the FSG layer and silicon oxynitride layer, in which the silicon oxynitride layer prevents fluorine substance outflow therethrough from the underlying FSG layer to an overlying conductive layer.