Patent ID: 6153531
Filing Date: 2000-11-28
Classification: H01L

Abstract:
A method for making reliable interconnect structures on a semiconductor substrate having a first dielectric layer, comprising:plasma patterning a first metallization layer over the first dielectric layer;forming a second dielectric layer over the first metallization layer and the first dielectric layer;forming a plurality of tungsten plugs in the second dielectric layer, such that each of the plurality of tungsten plugs are in electrical contact with the first metallization layer;plasma patterning a second metallization layer over the second dielectric layer and the plurality of tungsten plugs, such that at least a gap over at least one of the tungsten plugs is not covered by the second metallization layer;submersing the semiconductor substrate into a dilute acid solution until a tungsten oxide passivating film is formed over the at least one of the tungsten plugs that are not covered by the second metallization layer, wherein the tungsten oxide passivating film is insoluble to basic solutions; andsubmersing the semiconductor substrate into a basic cleaning solution after the submersing into the dilute acid solution to remove plasma patterning polymer residues, wherein the tungsten oxide passivating film that is insoluble to basic solutions prevents the at least one of the plurality of tungsten plugs from eroding in the basic cleaning solution.