| abstract |
The present invention provides a method for the simultaneous removal of an oxygen and/or nitrogen-containing dielectric antireflective coating ("DARC") during plasma etching of an underlying layer in a film stack. According to the method of the invention, the film stack is etched using a plasma containing reactive fluorine species. The concentration of reactive fluorine species within the plasma is controlled based on one or more of the following factors: the oxygen content of the antireflective coating, the nitrogen content of the antireflective coating, the thickness of the antireflection coating layer, and the thickness of the underlying film stack layer. The disclosure of the invention provides preferred combinations of plasma source gases which provide for the simultaneous removal of an oxygen and/or nitrogen-containing DARC layer during etching of an underlying etch stack layer, where the underlying stack layer comprises a metal silicide, polysilicon, or a metal. Also provided herein is a formula for determining the total amount of DARC removed using a given etch process recipe, based on the etch selectivity of the particular process recipe |