Copper post-etch cleaning process

A semiconductor processing method of forming an opening to a copper-containing material within a substrate, comprising:

• providing a substrate, the substrate comprising a semiconductor material having a first opening therein;
• providing a copper-containing material within the first opening;
• providing a mass over the substrate and over the copper-containing material, the mass comprising at least one of an oxide barrier material and a dielectric material;
• etching a second opening through the mass and to the copper-containing material, a surface of the copper-containing material forming a base of the second opening and thus defining a base surface of the second opening, said base surface being at least partially covered by at least one of a copper oxide, a silicon oxide and a copper fluoride;
• and
• cleaning the base surface with a mixture comprising, NO3−, F− and one or more organic acid anions to remove at least some of the at least one of a copper oxide, a silicon oxide and a copper fluoride from the base surface;
• wherein at least some of the organic acid anions comprise one or more carboxylate groups, and wherein the mixture has a pH of less than about 6.