Methods of forming copper-comprising conductive lines in the fabrication of integrated circuitry

A method of forming copper-comprising conductive lines in the fabrication of integrated circuitry includes depositing damascene material over a substrate. Line trenches are formed into the damascene material. Copper-comprising material is electrochemically deposited over the damascene material. The copper-comprising material is removed and the damascene material is exposed, and individual copper-comprising conductive lines are formed within individual of the line trenches. The damascene material is removed selectively relative to the conductive copper-comprising material. Dielectric material is deposited laterally between adjacent of the individual copper-comprising conductive lines. The deposited dielectric material is received against sidewalls of the individual copper-comprising conductive lines. A void is received laterally between immediately adjacent of the individual copper-comprising conductive lines within the deposited dielectric material. Other embodiments are contemplated.