The present disclosure pertains to a method for
plasma etching a
semiconductor patterning stack. The patterning stack includes at least one layer comprising either a
dielectric-comprising antireflective material or an
oxygen-comprising material. In many instances the
dielectric-comprising antireflective material will be an
oxygen-comprising material, but it need not be limited to such materials. In one preferred embodiment of the method, the
chemistry enables the
plasma etching of both a layer of the
dielectric-comprising antireflective material or
oxygen-comprising material and an adjacent or underlying layer of material. In another preferred embodiment of the method, the layer of dielectric-comprising antireflective material or oxygen-comprising material is etched using one
chemistry, while the adjacent or underlying layer is etched using another
chemistry, but in the same process chamber. Of particular interest is
silicon oxynitride, an oxygen-comprising material which functions as an antireflective material. A preferred embodiment of the method provides for the use of a source of carbon and an appropriate
halogen-comprising
plasma, to achieve selective etch of one oxygen-containing material compared with another material which contains a more limited amount of oxygen.