Method for making interconnect structures

Abstract

A method for making interconnect structures, particularly in a semiconductor integrated circuit, comprises the steps of: forming a conductive layer (3) forming of an insulating layer (4) above said conductive layer (3); creating a plurality of holes (6) in said insulating layer (4) and filling the holes (6) with tungsten thereby forming tungsten plugs (7), such that said tungsten plugs (7) are in electrical contact with said conductive layer (3); forming a patterned metallisation layer that overlies said insulating layer (4) by means of following steps: forming a continuous metallisation layer, forming an organic mask, etching in plasma said continuous metallisation layer, removing the organic mask in a dry way, and immersing the obtained wafer including the layers (3,4,5) and the tungsten plugs (7) in a cleaning solution to remove any post-etching residues is characterised in that, before immersing into said cleaning solution, the wafer is submitted to a plasma treatment containing F, H or a mixture of F and H. This plasma treatment may be combined with said dry removal of the organic mask, with the purpose of eliminating tungsten plug erosion.

Dependencies are inferred from the claim text.