Method for removing etching residues

摘要

A method for removing fluorine-containing etching residues during dual damascene process comprises providing a dual damascene structure having a copper conductor structure therein, a cap layer formed on the copper conductor structure and the dual damascene structure, and a low dielectric constant dielectric layer on the cap layer. The low dielectric constant dielectric layer formed by spin-on polymer method has at least an opening above the copper conductor structure. The cap layer is etched by fluorine-containing plasma to expose the copper conductor structure. The dual damascene structure is cleaned with a solvent and then the fluorine-containing etching residues are removed by plasma sputtering treatment or baking, or by a combination of both. The addition of baking and plasma sputtering treatment can prevent poor adhesion between the subsequent metal diffusion barrier layer and the low dielectric constant dielectric layer.