Method for etching silicon oxynitride and inorganic antireflection

Abstract

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.