Selective aluminum plug formation and etchback process

Abstract

An embodiment of the instant invention is a method of fabricating an electronic device over a semiconductor substrate having an interconnecting structure comprised of aluminum, the method comprising the steps of: forming a conductive structure (layers 120, 122 and 128 of FIGS. 1a-1d) comprised of a metal; forming a dielectric layer (layer 130 of FIGS. 1a-1d) over the conductive structure, the dielectric layer having an upper surface; forming an opening in the dielectric layer so as to expose a portion of the conductive structure, the opening having sidewalls; selectively depositing an aluminum-containing conductive material (material 136 and 137 of FIG. 1c) in the opening; and performing an etchback process so as to remove any of the aluminum-containing conductive material formed on the hardmask and so as to etchback any portion of the aluminum-containing conductor which is situated over the upper surface of the dielectric layer. In an alternative embodiment, the method further comprises the step of: forming a hardmask on the upper surface of the dielectric layer, the hardmask having an upper surface and is formed prior to the step of forming an opening in the dielectric layer; and wherein an opening is formed in the hardmask prior to the step of forming an opening in the dielectric layer.

Dependencies are inferred from the claim text.