Retrograde openings in thin films

摘要

Retrograde openings in thin films and the process for forming the same. The openings may include conductive materials formed within the openings to serve as a wiring pattern which includes wires having tapered cross sections. The process involves a two-step etching procedure for forming a retrograde opening within a film having a gradient of a characteristic that influences the etch rate for a chosen etchant species. An opening is first formed within the film by an anisotropic etch process. The opening is then converted to an opening including retrograde features by an isotropic etch process which is selective to the characteristic. Thereafter, the retrograde opening is filled with a conductive material, in one case, by electroplating or other deposition techniques.