US Patent 7252773 Clean for high density capacitors

One aspect of the invention relates to a method of cleaning high density capacitors. According to the method, the capacitors are cleaned with a plasma that includes fluorine-containing radicals. The plasma removes a small layer from the capacitors, including their sidewalls, and thereby removes surface contaminants. The method is effective even when the capacitors include hard-to-etch dielectric materials, such as tantalum and hafnium oxides. In a preferred embodiment, the plasma clean is combined with a solvent clean.